Question re: Urethane Caulk for Crack Filling...

[Perry H]

I have put urethane caulk in several cracks in my floor in preparation for laying down epoxy (Epoxy Guard). I have already pressure washed, degreased, and acid etched.

The caulk on the crack repair is about 1 inch wide while the crack itself is much smaller. This happened when I used a putty knife to scrape across the top of the filled in crack and the excess caulk was spread out.

My questions are:

1) Should I use lacquer thinner/mineral spirits to wipe off the excess that extends beyond the edge of the actual crack or is it better to leave as is?

2) Is there any need for me to do anything to the surface of the urethane to ensure that the epoxy adheres to it? E.g., should I abrade it? Can you abrade cured urethane caulk?

 

[LegacyIndustrial]

I don't like to put urethane under epoxy, ever.
The other contributors on the post have their own feelings regarding this practice.

Some caulks will act as bond breakers to epoxy as well.

 

[Perry H]

Well....

FWIW - urethane caulk is what I was directed to use by the manufacturer of the product I used.

I had a drum floor sander for hardwood floors sitting around from another project. I put an 80 grit drum on it and leveled the caulk bead with the floor. It turned out fine. Something less elastic than the urethane would probably be better, but as long as your crack isn't too wide it works.

My only serious problem was with the moth attack. I had 30+ of them stuck in the floor when I woke up - along with the evidence trail of their death throes. Live and learn I guess. They were attracted to something in the resin. I had a small bit of resin at my mixing table (in the dark) and several found that so it wasn't just an issue of them being attracted to the light. It took me a day to get them all out with a Dremel tool and tiny buffing wheels.

Anyone considering the DIY route would be well served by finding/making a friend that has put down a floor before. I feel like I could do it far better now with the experience of having done it once. I'm sure you get progressively better the more floors you have finished.

 

[wickeral]

I 'm in the process of using Epoxy Coat on our garage. EC said to not use any urethane product for crack repair. FWIW. Al W.

 

[Perry H]

I 'm in the process of using Epoxy Coat on our garage. EC said to not use any urethane product for crack repair. FWIW. Al W.

Even if you do (at least with the product I used), there is no horrible chemical reaction, the earth doesn't fall off of its axis, and the sky is still blue. I have little doubt that there is something superior though.

After I got the bugs out (which had nothing to do with the urethane caulk) my floor looked (and continues to look) great. I'll be putting more down in my basement in a couple of weeks.

 

[Mel M]

Would it work as well to just let the epoxy run into the crack? Nothing will really stop the cracking.