Do you want to make your own resin table? In our offer you will find the ideal resin Veropal UV Plus 100, which is directly developed for casting tables, doors, headboards and luxury furniture. But creating a wooden table with resin is a long shot. That is why we have prepared a detailed guide for you on how to create an epoxy table. And that from the very beginning - that is, from the selection of wood, its pre-treatment, to the final surface treatment of the cast table. A table with resin is created thanks to several consecutive steps:
Selection, preparation and penetration of wood
The first step in creating your own resin table is choosing the right and attractive piece of wood for your project. You can make a table out of anything, but you will probably want a piece of wood that has an interesting color, pattern, shape, etc. However, the selected wood must be properly matured, dry (preferably below 12 %, ideally below 10 %). Wood moisture is measured by wood moisture meters, either invasive types of meters where measuring tips are inserted into the wood, or non-invasive, which are simply attached to the wood and the device reads the moisture value from the measured conductivity values. There are a large number of meters of different quality – from cheap hobby ones starting at 12 EUR to professional ones at over 600 EUR, however, it is good to have a hobby meter so that you have a clear idea of whether the wood you have chosen is suitable for immediate work with epoxy, or whether the sawmill claims something different than what they sell. They have moisture meters on the sawmills, and have the wood you buy measured in several places on the wood. Wood moisture below 15 % can only be achieved in a dryer. When watering wood above 12 % moisture causes tension in the wood and it may (but may not) happen that the wood will bend, twist or even crack.
The wood should also be as flat as possible and as level as possible. Bowed timbers or twisted timbers in the propeller should be leveled with a router before making the epoxy table, or if we want to preserve as much as possible of the thickness of the material, level the planks using a special procedure with Veropal Fixwood resin.
So you have wood that is dry enough, interesting and straight. Now it needs to be pre-processed. First, you cut the wood to the required dimensions, get rid of loose parts, we remove rotten and weathered parts of the wood. In case you want to preserve the bark, only the cohesive bark should be preserved. You must take into account the fact that it will need to be properly penetrated due to its porosity and the consequent danger of bubbles escaping during the curing of the resin. You have to fix it to the wood as much as possible (either with nails with a small head or with a low-viscosity stabilizing resin Veropal WSB E-LV) to locally stabilize the bark and wood (both the bark and the wood become saturated and the hardened epoxide forms a very strong bond and everything becomes tougher). Fixing with resin is done by drilling a 3mm drill bit at a slight angle (to allow air to escape) through the bark into the wood at distances of approx. 7 cm. We blow out the dust and then coat the bark with Veropal WSB E-LV. We try to get as much resin as possible into the drilled holes. The resin then difuses in the hole along the wood fibers and, after it hardens, forms such anchor.
Before casting, you should roughly sand the wood with 80-100 grit sandpaper to get rid of possible loose wood fibers, but some people don't sand at all and leave a completely natural look, all according to taste. Before the next operation, the wood must be cleaned of dust, sawdust and other impurities.
Closing of wood – penetration
Next operation is very important if we want to obtain a resin with a minimum of bubbles or completely without bubbles after curing. Wood naturally contains a large amount of air in the pores and micropores. The wood must be sealed in the places that will be in contact with the resin to prevent releaseing of air during the curing of the epoxy system and creating of bubble. There are several options for doing this (e.g. the use of lacquers), however, for the best possible creation of bonds between epoxy and wood, we recommend using an epoxy system for sealing or penetration as well. Ideal material is Veropal PEN 10 – it is a compatible and fast epoxy resin with a mixing ratio of 100 : 40 and curing in a thin layer after application on wood in 4-5 hours. Especially suitable when you need to save time. It is suitable both for strongly absorbent surfaces, porous surfaces or slightly dusty wood, as well as for solid cohesive substrates. We apply the penetration with a brush, let it dry on the wood, and we recommend doing the process twice (for bark or very porous materials, carefully and several times).
Prepare VEROPAL PEN 10 penetration in smaller volumes, e.g. 100 ml, so that you can apply it immediately after mixing for about 2 minutes, occasionally mix slightly when wetting the brush. Mix in a wide-bottomed container to keep the column of resin as low as possible (this will extend the pot life a bit) and quickly apply to the wood with a brush. When a larger volume is mixed and left to stand in a column, the system in the cup can come to an uncontrolled exothermic reaction starts in the center of the volume, the resin hardens, cracks and turns yellow very quickly due to the release of heat. The temperature can reach a temperature exceeding 150 °C. If you ever want to use the brush again, wash it in xylene or xylene/acetone 2 : 1 and wipe it with a rag or paper.
Making of a mold and separation
Polypropylene (PP)
The best material is polypropylene, because it does not require the use of a separator or separation tape – epoxy resins do not adhere to it (so does silicone, but silicone molds are not used for tables widely). Polypropylene (PP) is relatively expensive – about 3-4 EUR per 1 mm board thickness and 1 m2 surface area (depends on suppliers). Prooved suppliers of these materials are Omniplast or Multiplast.If you plan to cast repeatedly, the investment in this mold material is definitely worth it, at least as material for the bottom of the mold. Regarding the thickness of the PP board, thicknesses from 2 mm to 10 mm are commonly used. PP with a thickness of 2-4 mm is used via sticking to other mold materials such as laminate, and as material for the bottom of the mold (the sides are then made of cheaper and dimensionally more variable wood, laminate, etc.). In the case of this thin PP plate as the bottom of the mold, removal of the casting is easier. Thanks to its flexibility, the casting with the mold is pushed over the edge of the table when removed, and by pressing the PP plate downwards towards the floor, the casting is easily removed. All-polypropylene molds make the casting work very easy, you don't have to think about separators, etc. In the e-shop, we also have ready-made molds made of polypropylene, which are designed for repeated use (or, in case of serious interest, a custom-made mold can be made).
Preapartion of material for mold
If you do not want to use polypropylene for the mold, wooden boards or laminate are most often used. However, these materials must be treated with a separator or separating polypropylene tapes during mold preparation. For wood as material for the form, we first sand the wooden boards (grit P80 or P100). The trick is to get rid of the protruding fibers and the separation tape adheres well. The tape must adhere perfectly to the wood, because if it does not adhere and the resin gets into the wood of the mold, it will act as glue. We always choose the dimensions of the mold at least 1 cm larger than the dimension we want to achieve. We choose a larger size so that the wood fits well into the mold, and we also have to take into account that 5 mm will have to be cut from each side when removing the mold for a better appearance of the edges.
Completion of mold
After cleaning the side of the plates that will be inside the mold, we have to decide how to separate the casting from the mold. We basically have two options, either to use a chemical separator (based on wax, Teflon, silicone, etc.) or to use a polypropylene separation adhesive tape.
Mold with polypropylene separation tape
Polypropylene separates well, but polyethylene tapes are not safe enough in ensuring of goon insulation of mold due to many edges. Use of printed separation tapes is risky even if the print is of high quality and has a top layer over the print – the print is stuck to the casting (but it can be sanded off). When using separation tape, the inside of the mold is covered with polypropylene adhesive tape, both the bottom and the sides. The individual strips are laid next to each other on the bottom with an overlap of at least 5 mm (after removing, these overlaps will stick to the bottom of the casting and will be visible, but could be sanded off). For side panels, the first strip is placed on the bottom edge of the side panel along its entire length with a slight overlap, then the entire side panel is taped with a slight overlap, mainly the inner part that will be in contact with the epoxy. On the outer part of the side, the separation tape will help to prevent the hot-melt adhesive from being absorbed into the wood and thus to better remove it from the side after demolding. Then the form will be assembled. First, the individual side panels are glued together in the corners with a hot melt gun and a frame is made from them. A continuous bead of silicone or acrylic sealant is then applied to the bottom of the frame, and the frame is pressed to the bottom of the mold with this sealant. Subsequently, with a hot melt gun, we apply hot melt glue from the outside of the sides around the perimeter of the contact between the sides and the bottom of the mold. The hot melt glue prevents the mold from leaking, and the solidified one comes off very well when the mold is taken apart. Once we have it, we apply another layer on top of the layer just applied and then one more layer, but this one is placed more next to the first layer with a half overlap with the first layer. It is done in 3 layers because one layer is not enough in most cases and leaks. It is better to use up a few extra fusible rods than if the resin starts to flow through the mold, and you find it leaking on the ground. At the same time, from the outside, we also go through the individual joints between the sides with hot-melt glue (but only from the outside). To close the internal contact surfaces, we use silicone or acrylic sealant (use white rather than transparent, it is easier to see where you have already applied and where not, and you can also see any holes, etc.), with which all the internal contact surfaces of the bottom and sides or sides putty well and smooth. After that, it is necessary to let the silicone sealant or acrylic cure, which in most cases takes about 1 day.
Mold with chemical separator
If you do not want to use polypropylene separation tape, chemical separators can be used to create a separation layer, most often based on wax, siloxane, oil, Teflon, etc. These separators are applied directly to an already assembled form (whether assembled similarly as described above, or screwed together). The separator is applied with a brush or cloth on non-absorbent surfaces (laminate, hardwood, steel, glass...). After its application, a continuous microlayer forms, which will separate from the mold after the epoxy has hardened. Separators are applied only on surfaces where the epoxy will be in contact with the mold. Work carefully and in the entire necessary area, because the epoxy acts as an adhesive and the unseparated part will be firmly attached to it. The most widely used separators are wax-based. Our separator V11 applies and dries relatively quickly and creates a high-quality separation microlayer of white wax. Do not touch the surface after application, as you could break the continuous layer of wax and the resin could adhere. It is important to always shake these wax separators in the bottle before application, because present wax settles to the bottom.
Veropal RA 100 shows even better separation effects. It is an industrial separator based on siloxanes, which is used on a large scale, for example, when casting large transformers or insulators for power plants. We prepared it in a spray for easier application. But when using it, be very careful about the applied amount. If too much separator is applied to the mold, and you pour the epoxide into the mold, the excess release agent will rise to the surface of the casting and create a greasy layer. Excess oil can shrink as if poured into the corners of the resin in the mold, creating such oil pockets. After the casting hardens, the oil will release, but you will be left with that empty pocket in the casting. Therefore, it is always important to take a paper towel after spraying Veropal RA 100 and spread the droplets on the surface to a continuous, slightly oily film forms on the surface of the mold.
Be very careful when assembling the mold and ensuring the separation, it will prevent leakage (resin on the ground + mess + complicated demolding in case of curing). These casting resins are very fluid and tend to find their way through even just micro-cracks, especially in the early stages of casting. Over time, as epoxy bonds form and the polymer crosslinks, the resin thickens and leakage is less risky. It often happens that, even with experienced people working in the field for years. Therefore, care is always necessary.
Calculation of resin consumption
How much resin is needed for your project? By subtracting the volume of the wood from the volume of the mold:
Calculation of the internal volume of the mold
Internal mold volume Vf = length (m) x width (m) x depth (mm). The resulting volume is in (L).
Calculation of the volume of wood
Wood volume: Vd = length (m) x width (m) x thickness (mm). From this volume of wood, subtract the approximate volume of cavities and gaps in the wood (in liters).
Calculation of resin volume
VP = Vf - Vd (in liters) and you get a very good estimate of the resin volume needed.
We always mix a little more resin than we calculate, mainly because of the shrinkage of the resin during curing. If you used tinted resin and you mix in an extra dose to fill in the depressions, you are very probably not able to match the shade. We recommend about + 5 to 10 %. The density of the VEROPAL UV PLUS system is very close to the density of water, so we can calculate that the weight of the mixture is approximately equal to the volume of the mixture.
Mixing and pouring of a resin
The temperature during casting should be 20-23 °C. The parameters described in the technical sheets are evaluated at this temperature. The resin and mold should also have approximately this temperature, so it is recommended to let the resin temper in the work room. At a lower temperature of some of the parts of the system, there is a risk of poor and uneven curing, formation of bubbles, etc. The room during the curing of the casting should be kept at a constant temperature. At a temperature below 19 °C, hardening slows down, and each degree down significantly increases this time, but the resin will harden. On the other hand, each step up accelerates the curing. There is a risk of overheating of resin and quick exothermic reaction. It is necessary to monitor the temperature of the resin with a thermometer and, if necessary, to solve its cooling if the temperature increases. In carpentry workshops it is usually not possible to maintain a constant temperature throughout the curing period, the temperature there, especially in winter, fluctuates during the day from e.g. 8 °C to 18 °C. When the temperature rises to 18 °C, polymerization, i.e. curing, will accelerate, when it drops to 8 °C at night, it will slow down again. Curing will take place in such a sinusoid, however, when comparing a product with the same bond conversion achieved (% bonds formed) cured under sinusoidal temperature conditions with a casting cured at constant temperature, the properties will be the same. It's just going to take a lot longer. For your imagination – curing in the refrigerator at 4 °C lasts up to 6 days compared to 17-20 hours at 21 °C!
Mixing ratio between component A and component B for epoxy systems is calculated for the given properties of the system and must be strictly respected (e.g. Veropal UV Plus 100 has ratio 100 : 40 by weight). Resins are mostly weighted, not measured by volume. Warning: When mixing, the mixing ratios set by the manufacturer must be followed exactly. It's pure chemistry. It is about linking the exact number of free groups in the resin with the exact number of free groups in the hardener. If you do not follow the mixing ratio and there are more of some components, there will be more free groups of some type in the system and this may cause the casting to harden incorrectly or unevenly and may be permanently flexible or too brittle. Weight as accurately as possible – the deviation should not be more than 2 %, otherwise there is a risk that the epoxy will harden poorly, stick or not harden at all.
We first pour the weighed amount of component B into the prepared container of the corresponding volume and into it the corresponding weighed amount of component A. We have empirically proven that the amount of mixed bubbles is smaller when component A is poured into component B compared to vice versa. In the case of pigmentation, we add Veropal PR pigment solution or Veropal PP pigment paste to the mixture in the ratio we have already tested, or use a metallic, pearlescent or alcohol pigment depending on the effect we want to achieve (see the following Resin pigmentation).
The mixture is then carefully mixed either with a ruler by hand for small volumes or with a slow speed drill propeller for larger volumes. This epoxy stirrer should have the correct shape to push the mixed mixture towards the bottom and prevent the resin from splashing out of the mixing container. We stir the mixture so that the two components are homogenized as much as possible and we also focus mainly on the places near the walls and at the bottom of the container. We recommend pouring the mixture into another container and repeat the mixing. It should eliminate risk of imperfect mixing of the two components and the formation of possible unhardened or badly hardened areas in the casting (there are still unmixed components of resin or hardener on the walls and bottom, and these then cause unhardened areas in an otherwise hardened casting or constant sticking of the casting).
After mixing, the mixed mixture is left to stand (about 45 minutes for Veropal UV PLUS 100), the majority of the mixed air in the form of bubbles will release. (ATTENTION! Faster epoxies, e.g. resin for thin layers or for jewelry, cannot be left to stand for 45 minutes, because they would come to strong exotherm, they could be left only for 7-10 minutes).
If we have a vacuum chamber, we put the mixed mixture in the container into the chamber and let it evacuate. Be careful, there will be a lot of air in the mixture and it will foam, so when raising the foam, regulate its height by releasing the vacuum. Wait until it stops foaming.
After standing, we start careful and slow pouring the resinous epoxy mixture in the prepared form with the anchored wood according to your wishes. Ideally, we pour through a 190µm lacquer filter, which will help us break the bubbles when pouring by touching the filter (a bubble larger than 190 µm will break after contact with the filter). Using a hot air gun, carefully run the heat over the surface of the cast surface. This eliminates bubbles, as we reduce the surface tension of the resin level. Bubbles burst when they come in contact with a stream of warm air. However, it must not stand in one place with warm air or flame, but constantly move the gun over the surface of the cast surface, otherwise you can start an exothermic reaction of the resin. Ttake into account the shrinkage of the material and pour it a little higher level. Due to shrinkage, the level of the hardened material will drop by approx. 1-4 mm, depending on the cast layer.TIP: The material shrinks slightly during hardening, so we recommend casting a larger amount of resin to compensate for these losses (these losses are directly dependent on the thickness or volume of the casting). For a 3 cm thick casting, it will be approximately 1 mm, for a 5-6 cm thick casting, we count on 3 mm. If we are filling the gaps between the timbers and our goal is to have the cured resin at the level of the boundary timbers, we recommend that the edges of the boundary timbers be treated with a stripe of neutral acrylic (to create such a barrier that the resin does not spill onto the boundary timbers) and that the resin be cast up to the height of the acrylic border.
The first visible changes in viscosity due to crosslinking will be seen after approximately 6-10 hours (depending on ambient temperature). Such a long open setting time allows further work on effects (further pigmentation, adding of glitters, etc. according to your imagination).
Faster systems, either Veropal UV Plus 121 (with the mixing ratio between component A and fast component B for Veropal UV Plus 121 is 100 : 20 by weight) or Veropal UV Plus 130 (with the mixing ratio between component A and B 100 : 30 by weight), can be cast up to a thickness of 1.5 cm at a time (for 130 it is 5 cm) and such layer hardens in 8-10 hours (for 130 approx. 1.5-2 days). Subsequently, various objects can be placed on the surface of the hardened system and covered with another layer (objects are best fixed with fast epoxy glue – e.g. Veropal QUICK, Veropal RAPID). So this procedure is used if we want to make a product with objects fixed at different levels. The interface between the hardened and new layer disappears when viewed from above. It is necessary to remove as much dust as possible, because dust on the surface of the hardened layer would reveal that the material has been poured several times. Viewed from the side, the interface will be visible (especially if we do not match the shade). To make interface not visible from the side, it is necessary to pour the next layer carefully during the gelation, so that the layers connect nicely and the interface disappears from the side as well (again, assuming that we have the same shade).
The following procedure may also be interesting for products with greater thickness. The product can be filled with resin to its desired height or just below (e.g. 2 - 3 mm) with the slow system of Veropal UV Plus 100. After curing, the volume lost due to shrinkage can be added to the desired level using the fast system. We will get an identical and harder surface, but on the other hand (compared to the slower system) it will be a bit more fragile.Pigmentation of the resin
The basic colors of Veropalu PR in the assortment are yellow, red, green, blue, orange, brown, black, burgundy, pink. Pigment solutions can also be mixed together in different ways to create other interesting colors. The color saturation in the cast is regulated by the amount of pigment solution. We recommend first dosing the solution drop by drop into a smaller amount, e.g. 100 ml of the system, and always mix and look against the light so that we can see the shade well. We repeat this until the desired color saturation. By calculating the amount of color solution consumed in 100ml, we will then obtain a fairly accurate amount of the pigment solution needed for the volume of the entire cast. For any conversion, the empirically obtained value of the volume of one drop of water = 0.05 ml can be used.
The basic and most commonly used colors of Veropal PP pigment pastes are white and black, but other colors are also available. Color saturation in the cast is ensured by exactly the same procedure as in the case of pigment solutions. The maximum dosage for pigment pastes is 2 % by weight. However, a small amount of pigment paste is sufficient to color the resin.
Beautiful effects are created by metallic or pearlescent pigments. Important for these pigments is the size of the mica particles (5-60 µm), which cause this effect. The size of these particles is directly responsible for the ability of the pigment to sink to the bottom or to remain floating in the resin, therefore, in order to avoid problems with the pigment settling to the bottom, it is necessary to use pigments that have been tested and recommended many times in applications (e.g. MyResin, Black Diamond Original, Eye Candy Pigments, Veropal Mica Pigments).
Different fillers, pearls, glitters, grains, powder pigments, phosphorescent pigments, etc. can be added to the system to achieve different effects. You can experiment with different times of addition, with different amounts, different combinations, mixing or not mixing, etc. We create a very interesting effect when we inject air into the resin during the starting gelatinization (gelation) – which results in effective clusters of bubbles remaining frozen in the resin after curing.
The removal of the mold must be done carefully, and we will do it no earlier than 5-7 days after the start of casting (in the case of Veropal UV Plus 100), but if we are not in a hurry, we can remove the casting only after 14 days. Processing of demolding should be done when the epoxy is fully cured, when it has reached the highest bond conversion values (% bonds formed). Patience will definitely pay off in the speed of sanding, in the low consumption of abrasive material and, last but not least, in a much more unified and beautiful surface after processing.
If you used our reusable polypropylene mold, unscrew all the wing nuts and use a rubber stick or a hammer over a block to separate the sidewall. Then lightly tap the other sides with a stick, turn the mold upside down and bang it upside down on the table 2-3 times. The casting should separate from the bottom of the mold and the sides and should be easy to remove.
If you used another mold that required separation, it will now show how well you coated the mold with the separator, whether you used a suitable separation method or whether you closed all the gaps with silicone and the resin did not leak or leak anywhere. If by chance it happens that the sideboard (e.g. from MDF) does not want to be separated, then you will have to use a chisel and a hammer, and patiently and carefully cut off the sideboard so as not to damage the casting (this is also why we already counted on a reserve during casting). The bottom plate is separated by gradually prying and bending the plate, in the case of a more flexible bottom, we pull the casting with the bottom of the mold over the edge of the base table and try to separate the bottom from the casting by pressing the bottom of the mold downwards. If we have a compressor, we can blow compressed air into the gap made between the casting and the bottom of the mold, and the casting will bounce off the mold. After removing from the mold, let the casting rest for a few more days. In general, if the casting will be processed further (milling, grinding, drilling, polishing), it is necessary to let the casting fully harden naturally – approx. 14 days after casting, as already mentioned. The point is that the conversion (the degree of cross-linking or the degree of epoxy bonds formed in the polymer chain) is as high as possible, because then this casting is machined very well and faster, the consumption of abrasives is lower and we also achieve a nicer appearance compared to castings processed prematurely. This time can be shortened by increasing the ambient temperature to 45 °C.
Milling
If we need to remove material from the hardened board to even out the unevenness after casting (for example, due to the shrinkage of the epoxy, its level dropped a little below the level of the wood during curing, or the resin ran under the boards, and we don't want that), it will be good to cut the board unilaterally or milling on both sides. Diffence in height of resin and wood is the next reason for this process. In professional workshops with a leveling sander or stretcher, this matter is solved quite elegantly and quickly, but the ordinary handyman does not have such a machine in his workshop. In the case of a draft, a razor mill is definitely better (thanks to the position of the blades in a helix) than a knife mill, because a razor mill does not cut the epoxy and does not make microcracks in the material. Even professional NC machines with appropriately selected milling tools are able to mill castings perfectly.
In hobby conditions, an ordinary router can be used quite reliably for this purpose. However, you need to make a simple router guide and an auxiliary guide along which the router guide will move. There are many materials for the production of such a guide, from planed wood, to aluminum profiles, metal traverses, etc. An average skilled person working with metal materials or wood should not have a problem making such a frame, the strength of the guide rails is important for the construction (they must not bend) and their flatness. There are already modular systems for the production of such frames, and there are also companies that will professionally manufacture such a guide to order.
We fasten the auxiliary line to the work table with carpentry clamps, we also fasten the casting to the work table. We place the router in the guide of the router and place it on the auxiliary guide, along which the guide of the router moves as needed. We clamp a suitable tool into the milling machine, e.g. a shank router for wood, e.g. 2-3 cm in diameter, set the material removal thickness (maximum 1 mm) and slowly (really do not grab) and patiently mill the surface of the entire board flat. If you have the option of vacuuming, vacuum the sawdust. It is important not to remove the material with the entire diameter of the milling machine, ideally with the radius, because if too much removal is done in one step, unsightly depressions may form on the surface of the wood and epoxy due to the cutting of the tool in the material. When removing material, it is also necessary to work very sensitively with the feed of the milling machine. Especially when transitioning between wood and epoxy, we have to respond to the change in material stiffness by changing the feed rate. It is ideal to work with a milling machine with electronic regulation for constant speed. Set the rotation speed to medium to slightly higher, it is necessary to check whether any melted spots are formed. It's slow, but take your time.
TIP: When you are at the end, we recommend reducing the removal once or twice, this time by only 0.1 mm, and milling the entire surface with this. You will make it significantly smoother and it will greatly speed up and facilitate rough sanding.
Be very careful – do not forget about work safety and protection of hearing, sight and respiratory tract!
Repairing of wood
After milling, small defects usually appear on the surface, caused in part by the decomposition of deeper layers of wood that were not visible before, and in part by the pulling out of the wood fibers by the milling machine. Rotten wood must be removed. All decay holes are then plastered or filled with resin, sometimes several times. Fast epoxy systems (5-30 min) are used, which can be pigmented and further sanded after approx. 2 hours after application. Ideally, sanded wood dust is mixed with such an epoxy to create a wood-colored putty that is applied to the torn area with a spatula. You can also use commercial sealants, e.g. Osmo Holzpaste, where we try to choose a shade of sealant that is as similar as possible to our wood. Interesting novelties are also sealants in the form of hot melt sticks that can be applied with a hot melt gun.
Reapiring of epoxide
Places in the epoxy can sometimes be torn out after milling. These areas can be repaired by re-potting with the same epoxy system that was used for the first pour. First, however, the damaged area must be properly blown away from the dust, then the mixed system is applied pointwise to the damaged area and blown with a hot air gun as needed. Let it harden. The advantage is the same refractive index and thanks to this the visual disappearance of the defect after curing. The disadvantage is that it will take several days for such places to cure. For this operation, it is also possible to use faster versions, e.g. Veropal UV Plus 120, when these small defects can be sanded after 1.5-2 days (the refractive index is almost the same). Quick epoxies with a working time of 5 to 30 minutes are also used, which can be sanded after 2 hours of application (e.g. Veropal QUICK). Someone recommends using instant glue, however, in the vast majority of cases, the repaired area is then visible. After hardening, these local repairs are roughly sanded.
Repairs of hardened bubbles on the surface
We first open the hardened bubbles on the surface with a sharp chisel, then clean the edges of the resulting hole. We clean it of dust (blow it with air), mix a little epoxy system, fill the hole after the bubble and let it harden. If necessary, sand and polish after hardening.
Sanding of the table made of epoxy resin
Manual sanding
For manual sanding of epoxy surfaces (e.g. jewelry, small castings), we recommend using sanding formats of sandpapers with different grit. The sanding formats must be attached to the sanding pads, and this can be done in three possible ways:
1) Use a small Super Assilex hand block with an intermediate layer measuring 72 x 125 mm. This block fits well in hand, is slightly flexible and the sanding format is easily attached directly to this block using the integrated micro velcro. For sanding larger surfaces, SUPER ASSILEX HARD INTERLAYER with a micro zipper is added to the hand block, which excellently ensures that the plane is maintained, which as a result ensures a higher quality and even surface.
2) Use a flexible Super Assilex hand pad. Thanks to its flexibility, this hand pad is especially suitable for processing round surfaces, radii, and differently shaped castings. The abrasive format is simply attached to it directly using the integrated micro velcro.
3) Use a hard Super Assilex hand pad, which is used especially for small areas. Abrasive formats are attached to it and then attached directly using the integrated velcro.
Based on the quality of the surface, we decide on the lowest grit to start sanding. The lower grain size will remove a larger amount from the surface, then it is necessary to take more subsequent steps with other grain sizes to flaten the entire surface. From the CRA KOVAX products, we recommend using the proven Super Assilex self-adhesive formats for combined wood and epoxy surfaces, thanks to the excellently uniform and shallow sanding marks formed by the innovative and unique grain structure. We recommend to start sanding with K240 or K360 grits. Paper tension is important for sanding. We sand with uniform movement and pressure in the direction of the wood fibers. Cross grain sanding is only used in special cases or to achieve a special effect. When sanding small objects, we use the reverse method, we stretch the sandpaper on a flat table top and move the sanded object along it. During sanding, we gradually alternate the sanding grits from a lower number to a higher number and do not skip the grits in a row by more than one grit. The basic recommended procedure is in these steps for Super Assilex formats: K240-K320-K400-K500-K600-K800-K1000-K1200-K1500. For effective fine sanding and polishing, we will subsequently use velcro-attached Buflex Dry formats with grits K2000, K2500 and then K3000. If the abrasive becomes clogged with sawdust, we clean the clogged abrasive and the surface with a microfiber cloth or an ordinary clean cotton cloth and use it again. Both Super Assilex and Buflex abrasives excel in their long service life and sanding speed for both wood and epoxy.
Machine sanding
The effect of the selected surface treatment on sanding
How much sanding is necessary is determined by the chosen final surface finish. If it is planned to protect the wood of the table with a surface treatment in the form of oil or wax, it is necessary to sand the wood to a maximum of 320 so that the oil or wax soaks into the wood. If we were to sand the wood up to 3000 like an epoxy, we would achieve a beautiful shine to the wood, but after applying oil or wax, nothing would soak into the wood. All the pores and micropores would be clogged with microdust after sanding and the wood would absorb almost nothing from the oil or wax, so it would not be protected in any way in the final stage (e.g. against water flowing from the glass, etc. – marks from the glass). Therefore, sand the entire surface to 320, and then sand with other grits, but only epoxy. It is better to cover the interface between the epoxy and the wood with masking tape. Very detailed shapes must be made by hand. Another possibility is the reverse procedure, and sand all this to 3000 even with the wood, and then glue the epoxy-wood interface and roughen the wood by re-sanding with 240 or 320 grit, but this unnecessarily increases the time and wears out the abrasive.
If we decide to protect the table with varnish (only varnish is able to protect both wood and epoxy), then it is sufficient to sand the wood and epoxy to a grain size of 600-800, then clean the surface properly (vacuum cleaner...) so that there is no dust on it, ideally and degrease with a degreaser (e.g. degreaser for epoxy and other surfaces LV PC 213) and then varnish (ideally varnish certified for contact with foodstuffs LV CC 250).
Proper machines for sanding
Eccentric sanders with an oscillating motion are used for machine sanding (for efficient use of the abrasive, a 5 mm range), as this type of sanding ensures a perfect surface of the sanded surface and simple application. However, for sanding the edges of the casting, a belt sander or a hand planer is more effective, or if these devices are not available, it is necessary to reduce the speed of the eccentric sander and thus reduce the removal and heating of the material (care must be taken not to create an eccentric sanding curve). Don't forget to protect hearing, sight and respiratory tract! Use a suitable vacuum cleaner. We do not recommend a drill for grinding, its rotational movement results in poorer surface quality.
Proper abrasive for sanding of epoxide
We searched intensively for 8 months for a suitable abrasive and epoxy sanding procedure. In the end, we evaluated the Japanese KOVAX abrasive as the best abrasive for epoxy in terms of the resulting surface, in terms of the lifetime of the abrasive and in terms of time savings, and in the final stage also in terms of the comprehensive economy of the grinding process. Of these, abrasives with holes have proven to be the most effective, as the holes serve to extract dust particles during sanding (ideal are Super Assilex discs with 15 holes for a sander diameter of 152 mm or Super Assilex with 7 holes for a sander diameter of 125 mm). However, if the abrasive does not have holes, or the sander does not have suction, the sanded surface and the abrasive itself must be cleaned more often. A regular cotton cloth or microfibre cloth is usually sufficient. Herewe will use a Super Assilex hard intermediate layer as well (15 holes for a sander diameter of 152 mm) with micro Velcro (for sanding with grit K240-K1500) or a Super Assilex intermediate layer with 7 holes for a sander diameter of 125 mm for efficient grinding. In the e-shop, you can already find complete sets of this abrasive with intermediate layers or intermediate layers.
Technique of sanding of epoxy resin
Epoxies should be cured before sanding, so sanding should be done after properly long time. The longer the time that elapses after curing, the harder the materials become and the better they work. We recommend starting sanding epoxy surfaces ideally 14 or more days after casting. Epoxies generally don't like high temperatures when sanding, so we choose a reasonable speed and don't put pressure on the sander to avoid excessive heating. Just as we don't put pressure on the saw, we shouldn't put too much pressure when sanding. At a high temperature, the processed materials become softer, the abrasive clogs more and it is harder to sand or polish, in extreme cases they even start to pull the polymer fibers. It is important not to stay in one place for too long when sanding the resin, as there is a risk of overheating and subsequent melting (the resin will return near the transition to the gel), excessive sanding of the abrasive and pulling of the fibers of the molten resin. Optimally, the sander should be moved continuously with slow movements. It is also necessary to pay attention to the variety of sanded materials and to stay more on harder or stiffer material, in this case wood. Failure to do so may result in cavities at the point of contact between the two dissimilar materials. When the sandpapers are clogged with epoxy sawdust (especially with higher grain sizes), these papers can be occasionally wiped with a cotton cloth, microfibre or knocked out.
Hard sanding
We sand the hardened epoxy in individual steps from the roughest grain to the finest. In the first phase, we are talking about hard sanding with abrasives (ideally use products from the TRI-PRO or Premium series, both with 15 holes) with grain sizes from P100 to P600 with the basic procedure P100-P120-P240-P320-P400-P500-P600, eccentric sander with velcro. We choose the individual sanding steps according to the state of the surface, but do not jump in grain size by more than 120, because otherwise traces of the previous step will be visible on the surface. The more grinding steps, the better the quality of the work. When changing to a finer grain of sandpaper, you must always thoroughly check the sanded surface to see if there is a deeper groove somewhere, because subsequent finer sandpapers will no longer be able to remove it and it will shine even more after the final polishing.
Soft sanding
In the second phase, we talk about soft sanding. Here we will use Super Assilex discs, again with 15 holes (for grinders with a diameter of 152 mm) or with 7 holes (for grinders with a diameter of 125 mm), with grits K600, K800, K1200 and K1500, also with Super Assilex hard intermediate layer (15 holes) with micro Velcro (in case of 125 mm interlayer with 7 holes). Subsequently, we replace it with a soft Super Assilex soft intermediate layer (with 15 holes for 152 mm or 7 holes for 125 mm) with micro Velcro to eliminate the formation of scratches, and the castings are gently sanded and polished using the attached Buflex Dry disc with grit K2000, K2500 and then grit K3000. For this soft sanding, we follow the same principles as for hard sanding. The resulting casting will already be very similar to transparent glass, but it will not be completely clear yet, it will be opalescent. Complete transparency and clarity is only achieved by polishing.
The most common surface treatments of epoxy tables are oils, waxes and varnishes. When choosing these materials, it is important that the materials are certified for contact with food, after all, these are tables where food will also be handled. Of these 3 types of products, only varnish protects both wood and epoxy. Epoxy after curing is an inert material resistant to acids, alkalis, oils, chemicals, etc., therefore it is used, for example, on floors in chemical and food processing plants, warehouses, etc. Thanks to this inertness, oil does not soak into the epoxy and is easily wiped off the surface, however, the epoxy brightens up for a while. That is why oils are used to treat wood and to bring out a beautiful wood pattern. Waxes in wood have a similar effect to oils, although they create a layer on the epoxy, which becomes shiny (to make the epoxy as transparent or shiny as possible), only a micro-layer remains on the surface of the epoxy, which is very easily removed from the surface (sometimes even with just a fingernail). Varnishes form a layer on the surface of wood and epoxy (the thickness of the layer depends on the method of application – compressed air or roller, brush) and after curing, this surface layer protects both types of materials. A varnish certified for contact with food (e.g. LV CC 250) should better protect the epoxy against scratches and, in addition, extend the life of the table thanks to increased protection against UV radiation.
Protection of wood with oil
There are a number of oil-based products on the market, and it depends on everyone what kind of surface they like and what kind of wood it is applied to. It is also good to find out in advance whether the product is suitable for contact with food and has a certificate. Among the most widespread wood surface treatments are oils, which are rubbed into the surface of the wood with applying beige pads. The wood should therefore be sanded to a maximum grain size of 120 to 180 in order to get enough oil into the wood. Separation of the epoxy and wood surface for sanding can be made with masking tape. The oil does not react when in contact with the epoxy surface, it does not soak into the epoxy and is wiped off with a wiping (polishing) white pad or microfiber cloth. The oil is usually applied in several layers with certain intervals, waiting for the oil to soak into the wood as much as possible. Then, after the interval defined by the manufacturer (e.g. for Howard oil, the interval between layers is 20 minutes), another layer is applied. After the last layer of oil, the excess oil is either wiped off with a suitable pad or simply wiped off with a rag and a protective conditioner is applied, which will seal and protect the wood. The exception is Rubio Monocoat 2C Oil, which is very effective and probably the best oil for surface treatment of wood, which is a two-component oil that has full protection of wood after a simple application in one layer. At the same time, it exists in 40 different color variants, so when applying the surface treatment, the shade of the wood can also be fine-tuned (lighten, darken, etc.).
The important thing after applying all the oils and waxes is to put all the rags, sponges, papers that you used when applying the oil or wax into a plastic bag and tie it (blocking the air) to prevent them from spontaneously combusting.
Protection of wood with waxes
Protecting wood with wax is very similar to oil, only the intervals between individual layers are longer (sometimes even 24 hours), it is good to apply individual layers and wipe off the excess wax.
Coating
When coating, it is necessary to ensure that it is as dust-free as possible, because you cannot hide much on the surface of the paint. This is often very complicated, but not impossible. Sometimes it is simply better to have such a board professionally coated in a paint shop. In hobby painting, a lot depends on the composition of the paint, which is directly proportional to the application method (viscosity is especially important). The majority of surface coatings for this application are two-component systems and again should be a food contact coating. E.g. varnish LV CC 250 with silicon nanoparticles for increased abrasion resistance meets the condition of contact with food, and 2 variants have been developed – a variant for spraying and a variant for brush or roller. Since this is the last operation, the result of which is actually sold, it should be flawless, and therefore for large tables and castings, we recommend and prefer spraying paint, because this way the paint is applied very evenly over the entire surface. Application with a roller is more suitable for smaller castings or products, because even if the flow of the paint is very good, on a large surface, in a detailed view, marks of brush or roller strokes can be seen. If you have never spray-painted before, it would be better to have someone more experienced do this, because you could end up ruining the product. Spray application is done in 2 layers of 25-30 minutes, with the second spray being applied so-called wet on wet – i.e. after spraying the first layer, wait approx. 15 minutes for the solvents to drain and then apply the second layer to the still wet layer. The varnish is then allowed to harden.
Polishing the epoxy table is a very important step, as it is the evaluation of all that effort. In addition, surface treatment sells, so this step must also be approached.
For polishing, it is best if the surface of the casting is previously sanded with fine-grit paper. In the event that we did not fine-grind up to 3000 grit and ended up before 1500 grit, we must continue soft-sanding. We will use Buflex 2000 abrasive on a soft intermediate pad. It is necessary to occasionally wipe the abrasive from dust with a microfiber cloth or cotton cloth, or use suction. After this sanding, we change the abrasive to Buflex 3000 on a soft intermediate pad and vacuum or wipe the abrasive again. This will prepare the surface for final polishing.
It is also necessary to have a suitable tool – i.e. a rotary polisher with a buffer between the layer and the polishing disc. You can also find a selection of very good polishers in our e-shop. An eccentric sander is not used for polishing, because it leaves behind traces of micro scratches even in the case of polishing pastes – the appearance is then "holographic" thanks to the small regular micro scratches. It is also possible to use a drill with a polishing attachment, but the work is then much more strenuous, it is not the best to manipulate, and it is also more difficult to react to pressure and revolutions. If possible, it is better to borrow a polisher. When choosing polishing pastes, it is better to choose an oilier base with the finest grain as possible, because they dry more slowly. Don't underestimate the choice. We recommend using the Finixa POL10 polishing paste, which is a one-step nanotechnology-modified paste that polishes from the roughest grain to the finest and achieves a high gloss of 95 %. Another great advantage of this paste is that it remains moist for a long time and reduces the risk of dry powder residues. We apply the Finixa POL10 paste ideally to a short fiber or at least to an orange POP 714 polishing disc with a diameter of 150 mm with a maximum speed of 700 RPM, but less is better, and rub it over the polished surface. At lower speeds (up to 700 RPM), we also control the temperature of the surface beautifully and prevent possible local softening. We press only slightly and proceed with a slow and even movement over the entire surface of the table. Definitely don't stop there. At the end of the polishing process, clean the surface either with a polishing cloth or with a black POP 914 disk with a diameter of 150 mm, attached with velcro asymmetrically, in order to obtain the so-called orbital movement. Then wipe with a microfiber cloth.
UV radiation, direct sun
The Veropal UV Plus epoxy system is a system that is characterized by excellent resistance to UV radiation, especially compared to other epoxy systems and in the long term. However, products from this system are intended for interiors and it is recommended to be placed out of direct sunlight – this prolongs the product's appearance.
Hot objects
When using the Veropal UV Plus system on table tops or bar counters, we recommend placing potentially hot objects on heat-resistant mats, otherwise the resin could be damaged at the point of contact with the hot object (color change, wheels, etc.)
Scratching
In the event that a scratch occurs due to contact with a sharp object, this scratch can always be repaired locally by re-coating the area with resin and re-polishing the damaged area to its original appearance. Re-sanding and re-polishing is also recommended if micro-scratches from normal wear during use have already destryed the original shine from the table.