How to fix a sticky or tacky epoxy surface
If the entire surface is soft, wet, or sticky after 48 hours, there are two possibilities:
- The epoxy product was under-mixed. Unfortunately, as much as we stress this as the most important part of the project, it can still occur and is the most common cause of this problem. If you do not mix epoxy long enough or fail to scrape the sides and bottom of the container while mixing, you will find under-cured epoxy. The resin component tends to sit on top of the mixture while in the bucket. If it is not rigorously pushed down into the mixture with the stir stick during blending, you can end up with areas that are hard/dry and other areas that are sticky or tacky and can't harden.
- The product was inaccurately measured. You must follow the strict 1 to 1 ratio by volume for table top epoxy. Do not guess or eyeball these measurements. Merely dumping the product from their original containers is not a proper measurement. The product MUST be measured with properly using a graduated tub.
- If the surface is hard but only slightly tacky, a new flood coat can be applied over the entire surface. The new product will dry hard as long as procedures have been precisely followed.
- If the surface is wet and soft, you'll have to remove as much of the material as possible with a paint scraper or knife. Use denatured alcohol or acetone when necessary to help remove the wet epoxy. Mix a new batch and apply it as a new flood coat. The new coat will cover up almost all the effects of the previous error. Be certain to follow the proper mixing procedures.
If the surface has small sticky or soft spots:
The most common cause of this is scraping or brushing from the side or bottom of the mixing container while pouring. It is natural to want to use up every last drop you have mixed. However, when you pour onto the surface, you should just dump it out and set the container down.
When you pour, don't attempt to scrape any residual epoxy out of the container. If it isn't pouring out naturally without assistance, it's because it wasn't blended well enough. Just leave that residual mix inside the container. If you use a stick or brush to try and use every drop, you will very likely end up with sticky spots.
You may also end up with sticky areas due to the mixture not being completely blended. The resin component tends to sit on top of the mixture while in the bucket. If it is not rigorously pushed down into the mixture with the stir stick during blending, you can end up with areas that are hard/dry and other areas that are sticky or tacky and can't harden.
- If the sticky spots are hard and only slightly tacky on the surface, you can do another pour over the entire surface. The new product will dry hard as long as you've followed the mixing and pouring instructions precisely.
- If the sticky spots are soft and wet, you'll have to scrape or cut out as much of the soft material as possible using a paint scraper or knife. Use denatured alcohol or acetone when necessary to help remove the wet epoxy. If you are left with deep depressions, your next coat should be used just to fill in the areas in which you scraped. Let this coat settle for four hours, then a new full coat can be completed. This will hide the imperfections and leave you with a hard, glasslike surface.