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This is an EIR and Sitka build that I pore filled with Epoxy and then finished with Shellac. To be more specific, I put on a couple of coats of Seal Coat and then a couple of coats of Hard Shellac (the stuff from Australia). I let it cure for a month and today I decide it was time to sand and polish.

I was using my random orbital sander and used 320 and 400 before switching to the micro mesh pads. My normal order was top, back, then sides, and then swap out to a finer grit. On the top and back this seemed to work fine, with the exception that I probably needed to level things better before switching to the micro mesh.

With the sides, I had issues with random gummy spots developing. It really looked like gum that had been stuck to your shoes and turned black, but was very hard. I thought I might have been burning the finish and started using the micro mesh wet. This seemed to be working better, but then more of these hard gummy areas developed. I had to get a scraper out to get the stuff off, which means I am probably down to wood in a few spots that will need to be repaired.

Questions:
1. What did I do wrong? Is the issue with using the ROS rather than sanding by hand, or is it the case of using premixed shellac, or is it something else entirely. This only seems to be happening on the sides.

2. Where do I go from here? I am thinking that I need to start back at the beginning with the sanding and do a better job of leveling before I move to finer grits - maybe even do this by hand with a block until it is pretty level. At that point, I will probably still need to do some fixing - around the sound hole it looks like I may have gone down to bare wood with the sanding.

One option I am considering is sanding the back and sides as level as possibly then switch to Tru-Oil which may be an easier finish for me to apply flat. Even after sanding back, I would think the wood should still be sealed pretty well with the Shellac.

Will appreciate all comments and advice.

Greg

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Greg Hatcher
North Carolina

When any finish becomes gummy-to much heat was put to it.
Also what cut was the Shellac?
Was it a waxed or dewaxed ?

The sides are a smaller area than the back or top .
The ROS puts more pressure on this smaller area.
Good thing is shellac is a workable finish.
Fix the bare spots and sand by hand .

Mike

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Mike Collins

I wonder if you've sanded through the shellac? Seems 320 and 400 are pretty rough when you have only four or so coats on. Maybe the hard shellac works differently than the shellac I'm used to.

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A higher purpose for wood.
Rich Smith
Issaquah, WA

Mike: The SealCoat is a 2 lb cut and I believe the Hard Shellac is a 3 lb cut. I will try to level sand the sides by hand and scrape off the gummy spots if needed then I will touch up the bare spots and let it cure for a while longer.

In general, is it safe to use to ROS on the top and back with Shellac? I get much better results with the sander than I do by hand.

Ricardo, I was not being specific when I said a couple of coats. I probably did 2 or 3 coats of deal coat for two days, and then the same with the hard shellac for 3 to 4 days. At times, I sanded back a bit to level things off, so not sure I can say how many coats are on there, but I think I had a good build up, until I had to start scraping it.

Thanks, Greg

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Greg Hatcher
North Carolina