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Epoxy in expansion joints...

Reflex

Well-known member
Joined
May 19, 2015
Messages
49
As some of you have read, I botched an epoxy job on a large portion of my shop floor (link here: http://www.garagejournal.com/forum/showthread.php?t=296309). Now, two weeks later, I've got the the floor almost all re-prepped, have ordered new primer and epoxy, and I'm in the process of cleaning up the dust.

Yesterday, when I walked into the shop, I noticed that the smell of epoxy was almost gone. I realized that what I had been smelling was likely uncured epoxy. It appears that when I cleaned out the expansion joints, I removed the majority of uncured epoxy reducing the scent. Since I could still smell some residual epoxy, I reasoned that there must be some uncured epoxy left in the joints. I was right.

When I cleaned (or cleared) the joints I used a Skillsaw (circular saw) with a masonry blade. The blade fit nicely into the joint with just a few thousands left on each side. I set the saw to almost the full depth of the expansion joint. Where the epoxy was hard, removal was dusty but not to tough to do. Where the epoxy wasn't cured, it was extremely difficult to move forward.

I stuck a screwdriver down into one of the cracks and found some very uncured epoxy at the bottom. The depth of the expansion joints is roughly 1 1/2". I set the saw to about 1 1/8". Even if the saw was set to full depth, the blade does not clean the gummy stuff completely. My questions are:

1) Do I need to remove this or will the new primer and epoxy harden over it?
2) If I need to remove it, any idea on how?

The width of the expansion joint is approximately 5/32". I can't think of any tool that I could get down in there to either remove the balance of the epoxy or scrub with xylene once balance of the gummy stuff is cleaned out.

Thoughts are ideas are appreciated.

Thanks,

Reflex
 
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Reflex

Well-known member
Joined
May 19, 2015
Messages
49
Guys,

Entrapping by using some sort of backer-rod is a great idea. Thanks a bunch!

I'm assuming your talking about foam backer-rod shoved into the slot??

Reflex
 
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CNGsaves

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Joined
Sep 26, 2012
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13,233
Location
KS and OK
Question for Flooring guru's - - - - if OP were to use foam backer rod to fill bottom section of that expansion joint, then fill rest of joint with silkaflex that he let cure fully, would he then have prepped floor ready for epoxy ???
 

benwah

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May 21, 2014
Messages
980
Location
Crested Butte, Colorado
Question for Flooring guru's - - - - if OP were to use foam backer rod to fill bottom section of that expansion joint, then fill rest of joint with silkaflex that he let cure fully, would he then have prepped floor ready for epoxy ???

If you're talking about the Sikaflex polyurethane caulking, No. Sikaflex should not be used UNDER epoxy. If you'd like to go that route, finish coating your floor then fill joints with caulk afterwards.

If you want to fill your joints prior to coating, use a 100% solids epoxy filler/surfacer or a polyurea with aggregate or sand.

If you're worried about cracking, use a flexible epoxy.
 
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