How many days from fresh epoxy to get single stage down?

DanMcG

Promoted Users
I should know this but I guess I don't.
On Monday I shot 2 coats of epoxy over180 sanded epoxy and hoped to be sanding with 400 and sealing with a reduced epoxy sealer tomorrow (Thursday) followed up with the SS the same day, But the weather is looking bad so it might not happen till Saturday (5 days) The truck is outside but under a UV50+ canopy which is suppose to block almost all UV light, (if you trust the Chinese guy who made it. )
So how long can it go before I have to hit it again with 180 and reprime it?
 
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Epoxy sticks to itself well. I don't see there being any issues Dan. The whole recoat window thing gets confusing. I get confused over it sometimes. Essentially though it has to be well out of the window for any possible adhesion issues. Being you have sanded the epoxy, will be applying epoxy as a sealer and only 5 days out then you will be fine. Where you might get into trouble is being 14 days or longer from when it was applied.

Google search for more reading on this
 
Thanks Don, Weather here is on and off crazy, but I bet you're experiencing a lot more of it then I am.
The whole recoat window thing gets confusing.
Thank you Chris for reassuring me I'm not the only one, and also for showing the google search method again... that works a lot better then the search here on the site.
 
Dan be sure to apply the sealer shortly before you go to single stage. Meaning don't seal then wait 2 or 3 days. If you have a solid uniform surface then you can reduce the epoxy 1:1:1 and go to single stage in 30 minutes. If you reduce it 1:1:25% (1/2 part) then you want to wait 4 hours minimum to overnight. You could possibly go to SS sooner than that at that reduction but 4 hours would be "safe". 12 hours "ideal". Be sure to not have any missed spots, meaning get very even and complete coverage (spraying wise not actual hiding coverage.) 1:1:1 is not going to cover (hide) completely. 1:1:25% should cover (hide) well. Unless it's white.
 
The recoat window does get confusing, and more so when the vehicle has been outside under a cover of unknown effectiveness. If there is any question, use of a lesser reduction improves the effectiveness of the epoxy in adhering to aged substrates. It's almost on a case-by-case basis what can be done. Personally I might use a 25% reduction if the rig has been sitting outside for close to a week, (1:1:0.5) but it's a pretty subjective call. For another example, if something has always been inside, you're okay using 1:1:1 for up to a month after the last epoxy was applied, as long as it has been well and recently sanded.
 
Thanks Don, Weather here is on and off crazy, but I bet you're experiencing a lot more of it then I am.

Thank you Chris for reassuring me I'm not the only one, and also for showing the google search method again... that works a lot better then the search here on the site.
Beryl missed us completely. Our fellow member @RosharonRooster was not so lucky and took a direct hit but they are well and now have power.

Don
 
All really depends on whether you need to seal to get a uniform base or if you already have a uniform base. 1:1:25% is better for getting hiding coverage. If it's uniform already then 1:1:1 works really well and less wait.
 
Will the 1:1:1 epoxy that I just mixed up for sealer still be good (in a sealed mixing cup) tomorrow?
I know if it was unreduced it wouldn't be an issue but wasn't sure about it added reducer.
No sooner did I mix it and my A-fib kicked in. Going to call it a day and try again tomorrow.
 
It will settle horribly, but I think it should still be usable. Try keeping it in something with a tight lid and somewhere cool (not cold) if possible.
 
Out of curiosity, if you sanded the cured epoxy, wouldn't paint still have mechanical adhesion and be fine? Just no option of not scuffing it? Paints do still have the option of mechanical adhesion, don't they?
I understand that we prefer to have both, but paints still "grab" the old school way too, don't they?
 
Yes, sanded epoxy does still have the mechanical adhesion. It would be fine to spray over that. If it's been over a week or so a red scotch brite pad would be advised to go over it just in case it has " healed itself " .
 
Out of curiosity, if you sanded the cured epoxy, wouldn't paint still have mechanical adhesion and be fine? Just no option of not scuffing it? Paints do still have the option of mechanical adhesion, don't they?
I understand that we prefer to have both, but paints still "grab" the old school way too, don't they?
Most paint other than epoxy adheres with a combination of chemical (solvent softening the surface) and mechanical adhesion. Even on paint (primer, clear, whatever) that is cured. Problem you encounter with epoxy that is nearly or fully cured is that it is completely resistant to solvents therefore you have to rely solely on mechanical adhesion. 180 grit scratches are enough to give strong adhesion, which is why they are recommended in combination with applying more epoxy.

Where it gets iffy spraying over fully cured epoxy is when you are sanding with 400 or 600 to then topcoat. Adhesion will be compromised. To what extent? It's hard to say. Adhesion will definitely be less than ideal and you can encounter problems down the road because of it.

Epoxy is a completely different animal than other refinish products and care must be taken when using it to ensure success.
 
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