10 replies to this topic

[tractor1]

Hi All

We had a relativly mild night in the west country last night so i decided to put some high build primer on my mini ready for it to be flatted at the weekend.

the trouble is it had a massive reaction with the etch primer, it's all blistered.

The only thing i can think it may be is that when i put the etch primer on i forgot to use the thinners that came with it i just used standard thinners and so when i put the high build on the same standard thinners melted the etch primer below.

could it be something as simple as that?

i bought all the paint from the same guy who assured me it was all compatable with the final cellulouse top coat.

does the thinners that come with the etch primer have a special hardener in it or something?

Thanks

[ginger_monkey]

I had a reaction with my high build primer. Bubbled up around the edge of my roof. I think it was a little wet in that area after some wet and dry work. Could this be the problem with yours.

[tractor1]

yeah mine looks like that

perhaps i didn't leave it long enogh to set then, i sprayed the etch primer on sunday night, and it's been cold and wet ever since so i guess it may not have set

i would say how long shold i leave nut how longs a piece of string beacause i'm not in temperature controlled booth it's weather dependent i guess.

[Paul Wiginton]

Did you put degreaser on the etch primer?
if you did, it probably absorbed a bit and wasnt completely dried out before applying the high build

Paul

[tractor1]

ah good shout i ran over the whole body with panel wipe then only left it about 10 mins (or however long it took mix the pimer) i'll leave it a bit longer next time just to elimate that possibility.

I've ordered some etch primer so hopefully ill have the old stuff sanded off by the weekend

[Paul Wiginton]

Etch it, leave it 20 mins then high build, dont degrease inbetween.

Paul

[tractor1]

ok will do,

the only thing i will ask is should the etch be fully set before i spray h/b over the top or does it not matter?

the reason i ask is because i'm not in a controlled room so it might take up 2 an hour or so to fully set which is ok but if it doesn't matter that the etch is fully set then i won't stand around for ages watching it dry!!

tractor

[midridge2]

buy your self a heat gun and use it, the best tool for body work and painting.

[In-a-mini]

personaly i wouldn't force dry the etch and primer you could aid it by blowing air across it with the spraygun just to get it moving and the solvent away from the panel. but dont go mad as you dont want it to skin over and trap the solvent in. If it were water based top/colour coat paints then a heat gun is a great idea looks like the solvent from the new coat has got under the other pain and wrinkled it

[midridge2]

i wonder why paint shops put the cars with new primer on into the oven.

[tractor1]

Hi All

just to let you know for future reference the reation happend in this case because of a combination of things mainly because i've never used the correct thinners with the etch primmer and so the etch didn't set off hard so the cellulouse high build thinner got underneath and blistered the paint.

i've just resprayed the etch primer but this time using the correct thinners but also heating the pannels up to arround 24'C so it baked off in around 2o mins, then i put on two coats of high build with no reactions at all, i've left that to fully cure for a few days now so i'll rubb it down and spray the top coat this weekend.

Thanks