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Help needed: handling issue in epoxy resin finish on table top

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Forum topic by contento posted 02-19-2018 02:43 AM 2850 views 0 times favorited 38 replies Add to Favorites Watch
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contento

46 posts in 1678 days


02-19-2018 02:43 AM

I’ve built an ash table top and finished it with epoxy resin following the directions provided to me previously for another project by Charles Neil (prep, seal coat, flood, wet sand, rubbed, etc). I have the top buffed down to a beautiful buttery satin, but I’ve got a couple of strange issues that came up….literally.

First, I’ve got some pits in the epoxy. Normally, i would have that it was bubbles that came up during curing that didn’t get taken care of, but I was diligent with the torch. It’s possible I missed them and now I have to deal with them. Charles suggested previously to abrade the pits slightly then drip a bit of resin in to fill with a toothpick. That’ll be the plan unless depending on the answers/suggestions I get to the next part.

the bigger issue is that I’ve got a couple of areas (a couple small and one pretty large) that appear to be raised “bubbles” of resin. They are higher than the surface and appear wavy (not glassy smooth like the rest). Something obviously happened to these areas during the pour or curing, and I have to figure how to handle them.

What I’m considering:
- trying to sand them down as flat and close to the surface as possible and hope I can sand and buff them to look like the rest of the table. If I can’t get those areas to look and feel like the rest, can I do another flood pour over the entire top to resolve it?

- remove the epoxy in those areas down to bare or nearly bare wood. Obviously, this might be a very tricky prospect (trying to sand a hole in the epoxy). Then, fill those areas back up to surface level and return to finishing. Will I be able to hide the hole with the new epoxy or might it look dramatically different from the rest of the top?

I would love to hear suggestions as to what might have caused it and what you think is the right way to attack it.

thanks all.


38 replies so far

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contento

46 posts in 1678 days


#1 posted 02-19-2018 02:46 AM

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Woodknack

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#2 posted 02-19-2018 05:14 AM

I would do what Charles Neil suggested and then scrape down the high spots and rebuff the whole thing.

-- Rick M, http://thewoodknack.blogspot.com/

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contento

46 posts in 1678 days


#3 posted 02-19-2018 12:15 PM



I would do what Charles Neil suggested and then scrape down the high spots and rebuff the whole thing.

Thanks, Rick. I did do what Charles said originally to get the top finished. I’m hoping to hear from him and other experts like you here on how to tackle the problems.

When you say “Scrape” what do you mean? scrape with a blade or sand?

There may be another “sticking” point – excuse the pun. I tried sanding down one of the small high spots (smaller than a dime), and when I did, it was sticky underneath. Granted, this was only a couple of days after the pour, so if that high spot was indeed some kind of bubble, I could see how it wasn’t cured thoroughly. I’ve let it sit now for a few more days and that sticky spot has hardened up. I’m hoping that if I do cut into those other spots, they don’t become a gooey mess.

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CharlesNeil

2433 posts in 3985 days


#4 posted 02-19-2018 01:58 PM

this is either a contamination issue, but more likely a mixing issue. Meaning for whatever reason the hardner didnt get fully mixed .
With that in mind the question is will it ever really cure ( just the spots ).
If it were me I would take a chisel and using it like a scraper , scrape out the soft material, then using some acetone, scrub down in the divot, . My reasoning here is so you dont have to did it all out and risk scratching the wood, , the acetone should remove any remaining uncured material.
Once clean, repour the divot , just slightly over full ,. When cured block sand it back to level and re buff .
My experience has shown that the repair will be invisible.

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Tennessee

2880 posts in 2629 days


#5 posted 02-19-2018 01:59 PM

There may be another “sticking” point – excuse the pun. I tried sanding down one of the small high spots (smaller than a dime), and when I did, it was sticky underneath. Granted, this was only a couple of days after the pour, so if that high spot was indeed some kind of bubble, I could see how it wasn t cured thoroughly. I ve let it sit now for a few more days and that sticky spot has hardened up. I m hoping that if I do cut into those other spots, they don t become a gooey mess.

- contento

Since epoxy cures chemically, not with the help of open air, my bet is you have a spot that didn’t get mixed well enough, and it will stay sticky for a long, long time. If the one spot finally cured, it had enough hardener in it to finally set. Only time will tell on the other areas.

-- Tsunami Guitars and Custom Woodworking, Cleveland, TN

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contento

46 posts in 1678 days


#6 posted 02-19-2018 02:10 PM

Thanks all. Sounds like I have a plan of attack. Appreciate the time to chime in.

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BobAnderton

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#7 posted 02-19-2018 02:41 PM

The OP didn’t say there were areas that didn’t cure or were soft, or sticky.

-- Bob Anderton - Austin, TX - Nova 3000 lathe, Alaskan Mark III mill, Husqavarna Saw

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contento

46 posts in 1678 days


#8 posted 02-19-2018 02:49 PM


The OP didn t say there were areas that didn t cure or were soft, or sticky.


Yes he (I) did, just not in my first post.


There may be another “sticking” point – excuse the pun. I tried sanding down one of the small high spots (smaller than a dime), and when I did, it was sticky underneath. Granted, this was only a couple of days after the pour, so if that high spot was indeed some kind of bubble, I could see how it wasn t cured thoroughly. I ve let it sit now for a few more days and that sticky spot has hardened up. I m hoping that if I do cut into those other spots, they don t become a gooey mess.


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contento

46 posts in 1678 days


#9 posted 02-22-2018 02:11 PM

Well, unfortunately, I was not very successful in removing the 1 of the uncured areas. I’ve come to the conclusion that the top needs to be sanded and re-poured. I’m going to tackle that (sanding) tonight.

I need to mix a large batch of the resin for this table (40” x 84”). Obviously, I have to insure thorough mixing to avoid this issue again. Are there any tricks of the trade I can implement? I’ve read that a wider container (not taller) will slow the curing time down. I mixed previously only by hand, but should I use a mixing bit in my drill (low speed to avoid introducing too much air)? Finally, can I thin this mixture a bit with acetone to make it flow easier like with the seal coat? What % is safe that won’t effect the finish hardness but effective enough to aid in the resin flowing and leveling?

thanks again all!

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CharlesNeil

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#10 posted 02-22-2018 05:24 PM

Im curious as to what became the issue .. ?

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contento

46 posts in 1678 days


#11 posted 02-22-2018 06:03 PM

craftsman inadequacies. LOL

I went about lightly scraping the soft spots and did fairly well on a couple of the major ones. Was able to get through the soft top layers and sanded/feathered the edge smooth. Those areas would take the re-pour ok. One area was very problematic. As I removed material near the edge of what I thought was the edge of the affected area, the area adjacent would begin to peel a bit. So, I had to extend my scraping a bit further. This went on and on. Ever pick at a small paint chip only to peel the paint off an entire surface? My half-dollar sized area quickly became double that with no clear end in sight. I couldn’t get a good edge on the area that I could sand and feather out. I tried creating a hard edge by using a razor blade and that worked a bit, but not great.

Charles, do you have any recommendations on preparing and pouring a large volume of epoxy? I picked up a wider plastic tub instead of a taller, narrower one. I also have acetone, mineral spirits, denatured alcohol. Can I/should I think the mix a bit to help it flow and if so, with what and to what percentage?

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CharlesNeil

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#12 posted 02-22-2018 06:05 PM

What epoxy are you using ?

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contento

46 posts in 1678 days


#13 posted 02-22-2018 06:18 PM

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CharlesNeil

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#14 posted 02-22-2018 06:23 PM

ok , so as i understand it , this is raw wood, you did the seal coat, no dyes no stains, just well prepped raw wood , am i correct ?

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contento

46 posts in 1678 days


#15 posted 02-22-2018 06:28 PM

yes sir.

I’m thinking the issue comes down to trying to mix, spread, and pour such a large volume of resin the first time. I know not to scrape the barrel to get more out, but I did everything else I could to get every drop on the table. That’s why I want to mix a very big batch this time. I’d rather throw an unused mixed pint away than come up short.

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