Baking a Sawdust Cake on Wooden Planks

I tried something new that I have wanted to do for quite some time now. I tried filling an engraving with resin. I have played with UV light cured resin for a few small pieces, but nothing as big as this project. I often have folks asking for outdoor signs and have been apprehensive because everything that I have tried so far, hasn’t endured the weather very well. I am making an outdoor sign to place near the driveway with our house number on it. My choice of wood is cedar for its weather resistance. I wanted to darken the numbers for better contrast and visibility. 

At first, I considered black spray paint to fill the engraving and sand any overspray off until a crisp line is achieved. This is a fairly common method, but I wanted to try resin. I chose a black mica powder to color the resin. This particular powder dye has a certain amount of metallic flakes in it that should allow for a little sparkle when headlights hit it at night.

I am a little impatient by nature, so waiting for resin to cure was going to test my restraint from trying to work the board before the resin has a chance to cure, usually days rather than hours. I followed the instructions on the resin, which was a 1:1 ratio, mixing 1.5 oz of part A and 1.5 oz of part B for two minutes before adding the mica powder to color the resin. The resin stated that I had 20 to 25 minutes of “Work” time where the resin could be poured before it begins to “cook off” and harden. When working with resin there is a clock that starts as the chemical reaction of the two components takes place. This process can be timed with a clock, but the resin itself has a vote in whether or not you will be able to get everything done before it hardens. Let’s just say that that I chose poorly in my application method, and the resin began releasing smoke and off-gassing as it heated up in the container. It had begun hardening before I could get it all poured into the engraving. It got so hot that the cup melted and distorted and the resin hardened inside the syringe that I was using to carefully place the resin in the grooves. 

Once the resin gets cured enough, for about two days, I will begin sanding and flattening the board out to see how it did. Applying heat from a Heat gun is used to smooth out the resin and force air bubbles to come to the surface and disappear rather than stay inside the resin. When the surface is smoothed out, a trapped air bubble can make a nasty blemish that is hard to smooth out. It is difficult to smooth out the board without removing a lot of surface material, which may reveal more air pockets that would need to be fixed.

I think that is the most frustrating part, I must wait two days before I can even see if it failed. In my other projects, I can usually tell right away when things are going wrong. This is where it feels like baking a cake. Baking is so much more involved than stove top cooking. The ingredients must be blended together in the correct order, the ratio of each ingredient must be correct, and then you put it in the oven and wait. More than once, I have waited the time required, only to find that it was overcooked, undercooked, or just plain ruined (there is a difference between Baking Powder and Baking Soda, just sayin’). Most of the time though, I can eat the mistakes to hide the evidence when baking, that is not a good idea with wooden signs.

Now we wait. It is time to wait on the resin to cure enough to sand down flat and wait to see if the numbers will be riddled with air pockets. Maybe for future projects I will find a resin that has a longer working time. With a longer working time, that will also entail a longer cure time. I do believe that resin will open up more products that we currently offer, but the learning curve is real. Just like cooking and baking, there is a learning curve. Watching videos can only flatten that learning curve so much, the rest must be learned through trial and error.