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Forum topic by moose1 posted 09-21-2015 10:48 PM 684 views 0 times favorited 8 replies Add to Favorites Watch
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moose1

4 posts in 487 days


09-21-2015 10:48 PM

Hey guys i have a cedar slab that I have put 2 coats of epoxy resin. I still have very tiny spots that the resin is sticky at. Almost like air bubbles that popped. Is there a way I can neutral the tiny spots so it’s not sticky anymore ? I don’t want to put on another coat and risk more spots to pop up.


8 replies so far

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bobasaurus

2675 posts in 2651 days


#1 posted 09-21-2015 10:52 PM

How long has it been curing? Maybe wipe it with a solvent like acetone or mineral spirits, then let dry? Or use a heat gun to accelerate the curing? I’m just guessing, I don’t have any experience with epoxy finishes.

-- Allen, Colorado

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MrUnix

4242 posts in 1666 days


#2 posted 09-21-2015 10:53 PM

Heat speeds cure time.

Cheers,
Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

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moose1

4 posts in 487 days


#3 posted 09-21-2015 11:48 PM

It’s only been a day to dry. But in comparison the rest of the bar surface will hardened within a day. And I’ve been fighting correcting small spots for about a 2 weeks. I will try the acetone to see if it will just neutralize the “sticky spots”

If I use my heat gun it creates a bubble over the surface.

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MrUnix

4242 posts in 1666 days


#4 posted 09-22-2015 12:11 AM

Sounds like you didn’t mix it well enough or didn’t use the correct ratio of hardener to resin. If left to cure at room temp, you should not need more than 24 hours. And applying heat should not create a bubble of any kind. I doubt acetone would help any other than to remove the sticky portion. Epoxy doesn’t ‘dry’, it cures through a chemical process – and if you don’t mix the stuff right, it may never fully cure.

Cheers,
Brad

PS: On large batches, mixing is critical. Mix until you think it’s good, and then mix some more.

-- Brad in FL - To be old and wise, you must first be young and stupid

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bigblockyeti

3668 posts in 1187 days


#5 posted 09-22-2015 12:16 AM

To speed the popping of entrapped air bubbles, I use an acetylene torch to rupture them as they surface to allow the epoxy more time to level before curing.

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moose1

4 posts in 487 days


#6 posted 09-22-2015 12:22 AM

Well the areas where the sticky spots popped up on. Is from the same batch where their aren’t any issues . Its not really a liquid bubble with the heat hitting it. More like air gets trapped underneath while the heat is being applied. SO you believe the acetone will help remove the sticky portion ? The spots are no bigger than a tear drop.

View shipwright's profile

shipwright

7175 posts in 2265 days


#7 posted 09-22-2015 02:09 AM

Sticky after 24 hours at decent temperature means poor mixing. Epoxy needs to be mixed at a precise ratio and mixed well. Just because some of the mix hardens does not mean it was well mixed.

Better explanation here.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees. http://thecanadianschooloffrenchmarquetry.com/

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Tennessee

2410 posts in 1981 days


#8 posted 09-22-2015 12:36 PM

Lots of people who are not used to these types of products almost always don’t mix enough.

I did it a couple of times, and days, even a couple weeks later had sticky spots.
The answer? Almost always had to remove it, (usually by rough sanding the epoxy off then resanding the wood surface to make it right again.

Then MIX! Brad is right. When you’ve mixed until you are absolutely sure it is all mixed – it is NOT. Mix some more. I also found over the years that some containers you might choose, such as cups can trap either resin or hardener in the corners at the bottom of the cup. Make sure your mixing tool can cleanly scrape that area during the mixing process.

As far as bubbles, my best results have come with heat guns or propane torches lightly waved over the bubble until it just pops, then get the heat away from it immediately.

It is all tedious and time consuming, and nowadays I try to avoid the whole doggone process, unless a customer is willing to pay big time.

-- Paul, Tennessee, http://www.tsunamiguitars.com

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