Monday, May 16, 2011

Epoxy Moon

Weather Underground (the Web site, not the domestic terrorists) reported rain for today, so I planned not to work. As it turned out, the weather was not bad at all, but the die was cast; Lydia and I watched the Angels drop a groaner in Arlington, then we got some long-deferred shopping done. 


After dinner, the evening was so fine, and the waxing moon so bright, that I decided to get the apron pieces all epoxied up.

Here is the customary nifty stratification picture (Part A on the bottom):


Here it is all mixed up:


To review: I used a container in which the volume of epoxy is taller than it is wide. The mixed epoxy needs to sit like this for a ten-minute induction period before use, so that the reaction between resin and hardener is able to get underway in earnest. The reaction generates heat, and heat accelerates the reaction; keeping the surface area small in this way keeps the reaction heat from dissipating too quickly. Notice that the mixture is completely uniform throughout; if it is not thoroughly mixed, it won't harden properly.


After the induction period, I poured the epoxy into a disposable styrofoam cup for ease of application and to avoid my wasting the measuring cup. I placed the apron pieces into a pan I fashioned out of aluminum foil in order to contain the epoxy, and then I began to apply the epoxy with a glue brush. Yes, pouring it on would have been faster, but I wanted to keep track of the absorption of epoxy into the wood. I didn't want to end up with a lot of epoxy sitting on top of the wood, which I would only have to sand off, and I wanted to see if there were any areas that soaked up more epoxy than others.

As it turned out, the wood was not anywhere near as degraded as I had feared. It didn't absorb much epoxy at all on the front; it all just stayed on the surface.


But the big surprise for me was that it absorbed more on the back side than the front. Sometimes this is a learning experience for me too.


I had anticipated that the front would be thirstier for the epoxy, because it is the side that has been exposed to the elements for 126 years. The fact that it was the back that was needier reveals the importance of back-priming wood; despite having been in total darkness all that time, the simple process of oxidation did plenty of damage on its own.


You'll notice in these pictures that the pieces are elevated above the foil; for this, I used these nifty items called "Painter's Pyramids." They are made of a neato plastic to which nothing sticks; the aprons will thus be able to drain and set on all sides without sticking to anything, and I'll be able to peel the cured epoxy right off the pyramids and use them again when I prime the aprons.

7 comments:

  1. Otis,

    Those aren't pyramids. Pyramids are quadrilateral. Those things are trilateral. I don't know what you call them, but they aren't pyramids.

    ReplyDelete
  2. Me,

    I didn't name them pyramids. The maker did. And don't bring up your conspiracy theories here.

    ReplyDelete
  3. You know, Otis, they say that talking to yourself isn't cause for worry, but answering yourself is.

    ReplyDelete
  4. Me,

    You started it. And stop with the italics already.

    ReplyDelete
  5. I like the wood carvings, they look like donut holes! Maybe I'm just hungry.

    ReplyDelete
  6. Never read this blog on an empty stomach.

    ReplyDelete

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