One of the things I’ve learned as an entrepreneur is to keep innovating and experimenting. Some things work out and others, not so much. You just press on. One of the recent experiments I’ve tried was using epoxy resin to fill in voids in my work. Ever wonder how they get those really awesome thick “bar top” finishes on tables and bar tops? In many cases, those are epoxy resin finishes (click here if you’d like to do more research on epoxy resins). Resin is also very useful for dealing with knot holes, cracks, and other voids. I recently took the dive into experimenting with resin finishes and thought I’d share some lessons learned to help you get started. I’ll also provide specific product recommendations you can purchase directly from Amazon and have delivered right to your door.
The most important step is protect yourself before beginning. These finishes are very toxic so make sure you are in a well-ventilated area. When I applied my first resin finish it was in the basement shop, so I flung the outer door wide open to let the air in and applied the finish at a table that was very near the door. In addition, make sure you are wearing long sleeves and are wearing gloves. You definitely don’t want this stuff on your skin. I also recommend wearing safety glasses, just in case you splash some up toward your face. This is not likely with the resin since it’s so viscous, but might happen with the hardener or dye.
The materials you’ll need are the resin, a hardener, and dye. The particular resin I’ve been using (System Three’s MirrorCoat) is mixed two parts resin to one part hardener (also MirrorCoat). One of the advantages of MirrorCoat is that it’s clear, so you can add dye (I’m using TransTint’s product) to make it any color you like. I chose black because I was filling in some voids in the black walnut gun cabinet I’ve been telling you about. Clear resin without the dye might make for an interesting finish in the black walnut as well. Here is the list of materials with links to Amazon if you’d like to purchase them:
I also recommend a plastic cup, measuring spoon, and scrap stick to use as an applicator. If you wipe the measuring spoon carefully with a paper towel, you can reuse the measuring spoon indefinitely. I like to use a plastic cup because it’s disposable and doesn’t require clean up. I’ve tried a couple different applicators, and a long thin piece of scrap wood seems to work just about as well as anything else.
The procedure. This stuff is very expensive so you only want to use the bare minimum required. I recommend finding a piece of scrap wood with a small knot hole to practice on. A small knot will not require much resin to fill in. During my first experiment I used two 1/4 teaspoons of resin, one 1/4 teaspoon of hardener, and one drop of dye. Start by pouring the resin into the cup. Then add the hardener. Then add the dye until the color has the opacity you like. Mix with the scrap stick and let one drop fall from the scrap stick into your void. Then add another drop, then another until the void has been filled. You want to slowly add drops, rather than pouring the resin so the air has time to escape and the resin has time to slowly fill all the gaps in the void. Fill the void to the top then wait about 5 minutes to check it again. You’ll probably have some settling. Then add more resin to top off the void. The resin will take about 24 hours to set and 72 hours to cure completely.
This is very important: make sure you set aside a time period when you have a few days in a row to check on the settling of the resin. You’ll typically find that overnight the resin has settled, and you’ll need to add some more the next day to level it off with your wood surface. If you wait more than 24 hours to do this, your resin may not bond together and you could end up with air gaps in your resin which would create an issue during sanding.
The finish. You may have a slightly convex shape over the void, but not to worry. You can sand the resin just like you sand the surrounding wood. I like to use 80 grit, then 120, then 180 as discussed in the post about my go-to finish on the cherry coat rack. As you can see from the picture, the resin really added some pizzaz to what could have been a distracting knot hole.
One caveat: the directions recommend using a propane torch to heat the resin and pop any air bubbles at the surface, but I’ve found that in the proportions recommended, the air bubbles escape before the resin hardens.
If you haven’t tried resin, but have always wanted to, give it a shot. For less than $70 you can be up and running in no time. This is consistent with our entrepreneurial mantra of fail fast and fail cheap which we wrote about here. If you have any questions, post below. I look forward to hearing from you about your experience with resin finishes.