Applying A Second Coat Epoxy Resin
Many who have ever worked with epoxy have likely attempted to layer it. Frequently, this is the only way to achieve a desired smoothness or thickness. What happens after the initial coat? Can you wait six months and then add additional layers to repair scratches or other damages? Are you able to repair imperfections from the first layer? Yes to all, which makes epoxy an even more attractive coating application.
Why You Might Need a Second Coat of Epoxy?
Sometimes it takes time for imperfections to show up in an epoxy finish. The right lighting or the right set of eyes can reveal an imperfection. Luckily, applying another coat of epoxy resin (after correcting the imperfections) can often leave a perfect, high gloss finish.
However, a cloudy or discolored finish cannot be fixed with a second coat. This particular problem will require removal of the imperfect/discolored epoxy and starting from scratch.
How To Apply The 2nd Coat
In most cases, preparing for a second coat requires sanding. The exception to this rule is if the second layer is poured while the previous layer is still tacky. Usually this is 4-6 hours depending on the temp/environment. If more than 12 hours has passed between coats, a light sanding will help to ensure the next layer properly sticks.
Step 1: Clean the Epoxied Surface
Remove debris, sticky areas, and anything else that is on the surface. Isopropyl Alcohol or Denatured Alcohol are common choices for cleaning.
Step 2: Fill Large Divots/Voids
If you have a large divot/void, you need to mix a tiny bit of epoxy and fill it first. This will seal the void (which is likely due from a crack/hole in the substrate) and ultimately help to achieve a level top coat.
Step 3: Sanding
Sanding epoxy is not difficult, but it does require patience for an even/thorough coverage. Prepping the surface of the epoxy so that another coat can “grip” the glasslike surface is critical. This means sand evenly across the entire surface area. Take Note: sanding the surface of epoxy will remove the high gloss finish. However, the next layer of epoxy will fill in all these areas, leaving the desirable high gloss finish. Be sure to clean the surface thoroughly after sanding, before pouring the next coat. Isopropyl Alcohol 99% works great to clean.
Step 4: Pouring Epoxy
Each brand is slightly different offering slightly different directions. In order to achieve the best possible results, the directions for use must be followed precisely. Most epoxies require waiting at least 4-6 hours before applying an additional coat. If correcting imperfection due to uncured or tacky epoxy (from the original coat), be sure to properly measure/mix/pour on the second coat. Repeating mistakes from the first coat will result in another imperfect finish.
Finishing Your Epoxy Project
Ideally, the second coat will have corrected any imperfections. The biggest hurdle is prepping the (imperfect) surface prior to pouring the second coat. The great aspect of epoxy is that it is can be layered. If over time the surface develops scratches, it can be sanded and recoated for a high gloss shine.