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Joe Hendershott
11-27-2018, 9:05 PM
Hello all. Trying to get a nice smooth finish with epoxy and always have some bubbles like in the photo. It is a test piece of mahogany veneer with West 207 special clear. Brushed on inside at about 68 degrees and 45% humidity. It flows out nicely but as you can see does not look good. The first coat was worse and was sanded down, wiped clean and this coat applied. What's the method you all use to get this done without the bubbles? Please point me in the right direction

Doug Hepler
11-27-2018, 11:11 PM
The photo looks better than anything I ever achieve initially. Maybe a two-part epoxy varnish will give you smoother results.

I expect two-part epoxy (West System or MaxClr) to develop surface irregularities. Normally, I like to use epoxy on the wooden mugs that I make. I scrape them & sand them out. Since they have a handle I can't finish the surface on the lathe.

I use a sharp card scraper to remove the bumps and then sand to 300 or finer, then 0000 steel wool. Wax will fill the remaining fine scratches. I have been known to give the surface a final rub with pumice or rottenstone instead of wax. I have been very pleased with the result.

I have tried thinning the mixed resin but that just slows down the cure rate. The finish flows and flattens well when freshly mixed anyway, so thinning seems to address the problem at the wrong stage of curing.

The surface area I work with is not huge, but the shape is a bit awkward, so it takes a bit of work to get it nice. I think that two part epoxy boat varnish might work better, but I know that MaxClr is claimed to be food safe when it has cured so I have not made the switch.

Doug

Doug Garson
11-28-2018, 12:38 AM
Try using either a hot air gun or propane/butane torch to heat the surface and pop the bubbles.

Wayne Lomman
11-28-2018, 2:41 AM
Air entrapment is addressed by filling the grain before you start, applying a thin coat followed later by a full coat, or as Doug says, gently warming the areas to pop the bubbles. Solvent less epoxies don't like thinning so you are best to go with option 1 or 3. Do it in a clean environment and it will work well. The sample is not far off the mark. Cheers

Joe Hendershott
11-28-2018, 7:26 AM
Thanks Doug, I will keep at it.

Joe Hendershott
11-28-2018, 7:27 AM
I also tried the hot air gun- had no effect.

Graham Wintersgill
11-28-2018, 9:50 AM
Joe

Another question is where the bubbles are coming from. Mix the epoxy gently then leave it to one side for a while, 207 is a slow hardener. While waiting for the mix to settle use the heat gun to warm up the veneer, this so that any air in the wood expands and then contracts as the veneer cools Apply a very thin coat with a flexible plastic spreader or putty knife. Keep applying coats. West is susceptible to UV breakdown and depending on the final use may need a coat of varnish for protection.

Graham

Joe Hendershott
11-28-2018, 7:36 PM
I'll heat it up and try again. I usually do not get good results getting it even with the plastic spreaders when it is so thin, hence the brush. I'll work on it more. I planned on using the Sikkens Cetol door and window on it.