Wondered if anyone has had similar problems to this:
I stripped my vw splitsreen van to bare metal (with a DA), filled the rough bits, primed it with 4/5 coats of super etch, wet flatted with 600 grade and topcoated it (about 1 month later) with Mac 5 cellulose. Did the shell first, then the removable panels later.
The shell came out fine, though I struggled to get the gun set up right and despite overthinning the topcoat, it went on a bit dry - looks fine now flatted and buffed.
Filled and painted the engine lid and tailgate next, was rushing to get them out of the way so just nibbed down the primer with a worn DA disc, the topcoat went on much smoother and held a much better shine, BUT the engine lid came out in loads of little pimples which appeared a few seconds after putting the first coat on, the tailgate was fine though. I thought I must have water in the air supply so set up a water trap system similar to that described on this site.
Filled and painted the doors next, no problems with the white paint on the tops (just nibbed down primer again as in rush) but got a few pimples in the blue on the bottom half (which I spent a lot of time wet flatting) - despite the water trap.
By now I was getting quite annoyed but put it down to water in the air supply and the water trap not working.
Anyway, painted the back bumper, overriders and brackets yesterday and the pimples came up worse than they have on anything so far - except on the brackets which I'd forgotten to prime with rest of it, ran out of super etch, so did them with an aerosol of grey primer.
Now completely baffled by it, but starting to think that they aren't caused by water, so could it be:
1. Residue from the DA discs I've use to de-nib (shell + panels which came out ok were wet flatted so would explain why there were no problems on those)
2. Has the panel degreaser got contaminated with something between me doing the shell and the other parts (doesn't explain why it only happened to some parts during the same spraying session)
3. Reaction with the super etch dependant on how long it was left to dry before applying the top coat. (shell was left a month, doors were left a couple of weeks but bumper was only left a couple of days)
I strongly suspect that it is 3, but anyone else experienced this or have any ideas.
Andrew
I stripped my vw splitsreen van to bare metal (with a DA), filled the rough bits, primed it with 4/5 coats of super etch, wet flatted with 600 grade and topcoated it (about 1 month later) with Mac 5 cellulose. Did the shell first, then the removable panels later.
The shell came out fine, though I struggled to get the gun set up right and despite overthinning the topcoat, it went on a bit dry - looks fine now flatted and buffed.
Filled and painted the engine lid and tailgate next, was rushing to get them out of the way so just nibbed down the primer with a worn DA disc, the topcoat went on much smoother and held a much better shine, BUT the engine lid came out in loads of little pimples which appeared a few seconds after putting the first coat on, the tailgate was fine though. I thought I must have water in the air supply so set up a water trap system similar to that described on this site.
Filled and painted the doors next, no problems with the white paint on the tops (just nibbed down primer again as in rush) but got a few pimples in the blue on the bottom half (which I spent a lot of time wet flatting) - despite the water trap.
By now I was getting quite annoyed but put it down to water in the air supply and the water trap not working.
Anyway, painted the back bumper, overriders and brackets yesterday and the pimples came up worse than they have on anything so far - except on the brackets which I'd forgotten to prime with rest of it, ran out of super etch, so did them with an aerosol of grey primer.
Now completely baffled by it, but starting to think that they aren't caused by water, so could it be:
1. Residue from the DA discs I've use to de-nib (shell + panels which came out ok were wet flatted so would explain why there were no problems on those)
2. Has the panel degreaser got contaminated with something between me doing the shell and the other parts (doesn't explain why it only happened to some parts during the same spraying session)
3. Reaction with the super etch dependant on how long it was left to dry before applying the top coat. (shell was left a month, doors were left a couple of weeks but bumper was only left a couple of days)
I strongly suspect that it is 3, but anyone else experienced this or have any ideas.
Andrew