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Adhesion issues, PLEASE HELP!!!

#1
I am painting a tank and fenders off a Harley for my buddy. They have been stripped with an 80 grit disc, 3 coats epoxy, blocked to 320, lightly rubbed with red scotchbrite, sealed with 25% reduced epoxy, set 8 hours @ 68 degrees, sprayed activated intercoat clear, then nason Wimbledon white, then intercoat again. Waited 4 hours, started taping out graphics, and it peeled up, leaving the primer exposed.

This is the second time this has happened, the first time I had just scuffed the original finish, sprayed epoxy, blocked, sealed, then nason white, then tape peeled it up.

I thought that it was because I had the parts setting in front of the heater and the air blowing on them cured the sealer too quickly, but this time the parts were on the other side of the shop

Please help, I'm at a loss. This was supposed to be a quick job and I've gotten an insane amount of hours into it.
 
#4
generally you shouldnt have had a problem here. some things to note though. intercoat is not needed before the base goes down. its not going to increase adhesion. its base just like the white is. #2 when you activated the intercoat, how much did you use? activator really helps adhesion BUT adhesion is weaker in the beginning then its increases as the activator hardens prob a week later as the paint sits. the more activator the worse this is. #3, no need to wait 8hrs after the epoxy sealer goes down. not that waiting caused the issue. just saying no need to wait. if you do 1 even and very thin epoxy sealer coat then put your white base on after it flashes dull. 15min or so. once your base is all on then let it sit 8hrs before you tape on it.
 

Barry

Paint Fanatic
Staff member
#6
Jimc is correct, I have run into this many times with the cheaper bases and the bottom line is the cheaper ones taking more coats to cover and a lot slower to dry, the answer is let the base when doing custom work set longer to get more solvents out.
Also activate the base when doing further taping, if you had gone to clear over the next few days the adhesion would have continued to get better.

Now how to test if I'm right?
where you peeled the next day test and it will be harder to continue peeling or not at all because the solvents rushed out once you broke open the paint.
 

orangejuiced86

Garage hack at night.....
#7
I had the exact same thing happen with Nason. The tape time on that base is stupid long. I had to repair where the paint pulled up. then when I rebased it i did one coat of intercoat on top and then let it sit over night. after that it was good to tape on.
 
#9
Thanks everyone. I don't like blaming the product because usually it's me! However, it seems like Nason might be to blame? I am using it for such a small part that I didn't want to buy a nicer base, guess I learned...

Everything was activated. I waited 8 hours on sealer simply because I was tired and needed sleep once I sealed! This morning it was hard on the edges. I smoothed the edges with 400, then put a coat of clear over it. I'll let it set a couple hours, then lay my stripe a touch lower where it is still the Wimbledon White, the rest of the tank is going to be dark green and black so it should easily hide the difference in the white sealer and base.

Probably overkill putting clear down, but I want it locked in before I try again. The base has cured for about 18 hours now.

Learning is so frustrating sometimes.

Can I spray my other bases directly over the fresh clear or do I have to scuffed?
 
#10
So the moral is: saving money can cost more.
And: slower is faster
I thought I was being slow...

I am not even sure it was about saving money. Its been a couple months but I think the reason I went Nason was because the paint code I wanted couldn't be mixed with DuPont in pint cans, and a quart for a pinstripe color seemed excessive. That or they couldn't find a paint code in Dupont

I don't have a paint distributor within 60 miles. I work at a parts store and we can have paint mixed and sent overnight with our freight. However, the people who run the refinish supply aren't the most knowledgeable, they just lost some good workers and only have 2 "old timers", all the rest are new this year. It's a struggle ordering a part that I have a number for, mu
ch less trying to get paint mixed to a certain code.
 
#17
The question that Jim C asked was how much activator did you use. They have told us a cap per a quart of mixed paint right? If you are doing a little bit do a few drops really help that much?
 
#18
activator makes a huge difference in adhesion and durability. it doesnt take much. figure a a cap full being maybe 1/2 oz so you would be around 1/2-1oz per ready to spray base. that actually quite alot considering that rts quart is probably 90% solvent.

for the peel up problem that mitch was having, i used to get this happening all the time with diamont base so its not just cheap bases. diamont would flash dull very fast and would be dry but would take a good 24hrs before the base would actually harden up. its that last tiny bit of tail solvents that need to come out. diamont was also so rich in polyester that until it had really hardened well it wouldnt adhere worth a crap. now with wanda all those problems went away.
 
#20
IIRC, they recommend 1 oz per sprayable quart. There is 29.5 ml per ounce so I just do 1 ml per mixed ounce. I have a small measuring glass for when I mix small amounts
 
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