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Hey all, I wonder if anyone has experience using microbaloons in epoxy as pore fillers. I’ll be filling Wenge soon and wonder if this may work. I am a bit skeptical about the long term effects on the wood.


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From what I've read, you should also be thoughtful about the long term effects on your lungs, so make sure to use an effective mask when handling. I know people who have been using these for a numbers of years with no ill effects on the wood apparently.

About 20 years ago when he was still building Mike Doolin had an epoxy tutorial on-line on LMI's (RIP) site. He used System III and microbaloons as the thickening agent.

I was at my witt's end trying to learn a decent method of pore filling and very close to giving up on building over not being able to find a solution for pore filling that worked. I followed Mike's method and it worked great the first time and saved building for me.

Later on I found that the microbaloons are not necessary (but for your application Wenge they may be a good idea) and finished many guitars after that with just straight up, quality epoxy including Pacer Products, West, Bob Smith and System III.

Long term effects I've got that guitar with microbaloons in my living room and it looks great. In fact some have experienced epoxy shrinking back into the pores, I have not but it would seem to be that microbaloons would be a good hedge against shrink back too.

There is a good tutorial by Todd Stock on epoxy pore filling in the tutorial section of the forum and on Youtube. Todd uses a squeegee and others including me have had good results with a credit type card used as a Squeegee.

Expect two sessions, maybe three depending on your viscosity and squeegee technique. I found that simply getting all the pores wet in the bottom of the pore was the key to the first session and the goal. Epoxy sticks great to itself so the second coat was the heavy filling once the bottom of the pores was covered with epoxy in the first session.

Epoxy also greatly pops the figure in the wood making the wood even more beautiful and at times dramatic.

Yes microbaloons are not to be inhaled so a mask is a good idea!