poor adhesion spraying base next day

B

bmxpegan411

Hi Guys,

I sprayed some epoxy as a sealer, then the next day sprayed nason base the next day. This was the inside of some doors. About a month later I taped the inside of the doors off to not get overspray on them, but pulling the tape up pulled the clear and base right off of the epoxy. Is this because the base had no catalyst in it? I've never had this issue before and read on this forum that spraying base the next day is OK to do. Any ideas?

Thanks!
 
generally you are ok the next day with epoxy BUT if sprayed very thin like a sealer, 1:1:1, it was fairly warm and the base was sprayed light with a fast reducer then yes it is possible. the thinner epoxy is the faster it will set up. as a sealer you generally spray it like its your first coat of base. let flash dull and your ready to go. 1 coat at 1:1:1 i wait maybe 10-15 min in summer months.
 
thanks Jim, that's what I was hoping the issue was because I sprayed all kinds of other stuff with the same base and they seem OK. Do you ever wait overnight to clear base or have extended time between coats of base? I think to avoid possible issues from now on I'll go sealer to clear all in one day
 
bmxpegan411 said:
thanks Jim, that's what I was hoping the issue was because I sprayed all kinds of other stuff with the same base and they seem OK. Do you ever wait overnight to clear base or have extended time between coats of base? I think to avoid possible issues from now on I'll go sealer to clear all in one day
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Treat basecoat and clear as separate steps, but seal and shoot activated basecoat at the same time. Clearing can be done hours later or let sit overnight and clear the next morning.
 
Jorge M. said:
Treat basecoat and clear as separate steps, but seal and shoot activated basecoat at the same time. Clearing can be done hours later or let sit overnight and clear the next morning.
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If the base is activated, it has a window also. Ive heard 12 hours
 
thanks for the replies! I've never personally activated base, but I've read on here that there are a lot of advantages to doing so.
 
The last Nason base I used had a mandatory activator. Maybe there is more than one kind of Nason base, but it's always a really good idea to activate. Not sure if that would have helped you here or not, I personally have never experienced that kind of adhesion loss. It almost sounds like it might have been a bit of solvent trapping that would resolve itself with some time in the sun.
 
I ruled out the theory of base not sticking because of the sealer closing up....After this issue I media blasted the inside of the doors, cleaned, sprayed epoxy as a sealer and base maybe 20 minutes later, then finished them off...that was about 2 weeks ago and now after taping the inside of the doors off the tape pulled the base right off of the sealer again, just as bad as last time. I can take an air hose and just blow the base right off of the sealer. Any ideas why this happened again? I'm at a loss for words. Never had this issue with Chromabase, and I've used nason a few times on door jambs without this issue.
 

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bmxpegan411 said:
I ruled out the theory of base not sticking because of the sealer closing up....After this issue I media blasted the inside of the doors, cleaned, sprayed epoxy as a sealer and base maybe 20 minutes later, then finished them off...that was about 2 weeks ago and now after taping the inside of the doors off the tape pulled the base right off of the sealer again, just as bad as last time. I can take an air hose and just blow the base right off of the sealer. Any ideas why this happened again? I'm at a loss for words. Never had this issue with Chromabase, and I've used nason a few times on door jambs without this issue.
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You don't mention activator. Ful-Base has mandatory activator:
http://www.axaltacs.com/content/dam...ments/TDS/NSN-TDS-Ful-Base-IF-Quality-Eng.pdf
 
I see two issues here, one is putting base over 20 minute old epoxy could very well be the problem.
2nd thing is no base or clear will have full adhesion the next day.
 
Barry, should the flash between the epoxy as a sealer and base be shorter, once the epoxy is dull shoot the base?
 
here is the deal with epoxy....if you spray it as a sealer and you spray it just a little heavy then it will need to sit the 2hrs to be safe but if you reduce it down and mix 1:1:1 and spray just a super thin coat then as soon as it flashes dull you are fine to go right to base. the 2hrs noted in the tech manual is the safe zone. this will insure the epoxy has had enough flash time before base is applied no matter who sprays it and how much. what you really want to avoid is spraying epoxy, go right to base then go right to clear. i have put epoxy on heavy plenty of time with only 10 min between but at that point i let it sit overnight for all solvents to flash before i clear. now if i would have cleared right after then the solvents are trapped and solvent trapped in epoxy slow its cure down to a major crawl.
 
shine said:
prospray will do the same thing.
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Thats twice you said that in two separate posts, can you please explain better. If you like please PM me as i could use the information if you dont want to post.

Sorry OP but I have/had same problem seems to have cost me a paint job.
 
Its a solvent issue, so most likley first cost of base not allowed to flash long enough or to fast reducer for temp used in the base.
Nason is slow so you may test a spot by letting first coat of base set 30 or more minutes and don't rush the epoxy.
 
It's always a good idea to stack the odds since so many things can go wrong. Adding activator to the base, extending flash times, using slow enough reducer, not piling on material, etc, make for a more sure result.

Just like many other things that end in disaster, paint failure is not usually just one cause, but a pile of little things going wrong all at once.
 
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