Epoxy as sealer recoat

Say08

Promoted Users
So was spraying engine compartment with base after epoxy sealer was going down. I got about halfway through and electric went off. Tank pressure didn’t get me finished. I can’t get back to for a week or more. It’s in a garage but not an ideal environment. Can I just wet sand base and reseal on top of it or does it need to be sanded completely off? It as worried as going over the base already there but the sealer that wasn’t covered.
 
I would just wet sand, wipe it down and recoat with base and continue on. Just my $.02
 
It’s automotive art. I’m not as worried about the base side it’s leaving the sealer uncoated that long and going over top of it. I can reseal what hasn’t been sealed but I didn’t know of the sealer going over base was a good idea
 
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So you have half base half sealer? Did you activate your base?

I'd be inclined to sand/scuff with 600 and re-seal with epoxy reduced 1:1:1.
 
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I agree with sprint. When I reduce epoxy, I use a 1:1:1 mix proportion which means equal parts epoxy, activator, and reducer. I think this is what sprint means, but there has been confusion on using percentages vs ratios on this site so I wanted to clarify that.
 
The base is activated. That is what I spray it at. My concern was spraying the sealer over the base coat as part of it is sprayed.
 
I would do whatever it takes to make the time to scuff/clean it up a bit and get base on the rest of it ASAP. Waiting over a week just invites a lot of extra work, imo.
 
I wish I could do that but had to be a few states away today and won’t be back until next week.
 
If temps are cool and the vehicle is inside, you can scuff it all down real good and proceed with base without issue. Although, I'd like to hear from Barry on this one to be sure. Putting epoxy back over base really isn't ideal, and the 7 day window is a rule of thumb that tries to capture all conditions. In cool weather, complete cure is much slower.
 
I agree with sprint. When I reduce epoxy, I use a 1:1:1 mix proportion which means equal parts epoxy, activator, and reducer. I think this is what sprint means, but there has been confusion on using percentages vs ratios on this site so I wanted to clarify that.

I technically probably under reduce as I only reduce the epoxy portion when mixing for sealer. For whatever reason I do sealer that way. I changed my post above as this gets confusing when discussing different methods.

If temps are cool and the vehicle is inside, you can scuff it all down real good and proceed with base without issue. Although, I'd like to hear from Barry on this one to be sure. Putting epoxy back over base really isn't ideal, and the 7 day window is a rule of thumb that tries to capture all conditions. In cool weather, complete cure is much slower.

I'd be curious to learn more on this as it was my understanding that when reducing epoxy the 7 day window no longer applied. I also thought that after 24 hours the adhesion benefits of epoxy sealer for basecoat were significantly diminished.
 
...I'd be curious to learn more on this as it was my understanding that when reducing epoxy the 7 day window no longer applied. I also thought that after 24 hours the adhesion benefits of epoxy sealer for basecoat were significantly diminished.
I think JimC has said that, and I don't have a reason to say one way or another whether it's significant to longevity, although I do have it on authority that long-term adhesion success may not be precluded by short-term adhesion failure (masking tape pulling the base off). The epoxy window is not easy to understand. I think that a good scuffing and proceeding is better than making a mess of things by shooting epoxy back over base, which would happen at least in the overlap areas if not completely. I don't like to cover soluble materials with catalyzed ones unless I'm doing a non-warranty job, it's just not a good idea. If it really came to that, in our shop we might just wipe the base off with solvent and start over, but that also seems pretty extreme in the circumstance, which is just an engine bay.
 
I am pretty sure Barry has told me once the reducer causes the epoxy to cure much faster and the window is much shorter. I has sprayed a reduced epoxy on a bumper once and sent him a photo. I did it outside. He told me to get it out of the sun if I was going to wait a few hours to spray the base on it because I reduced it 30%
 
Crash, if I decide to remove this would wet sanding or reducer be easier? It’s not that much but I did use activator in it.
 
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@Say08 , it's pretty tough to decide what would be the better route. I was hoping we could hear from @Barry on this on, it's not really a cut-and-dried situation and not one I have had to deal with. Being in a everyday shop environment such things simply don't happen. We'd just continue basing as soon as we could get air pressure going again.
 
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