[Yoshi]

A few weeks ago I did 2 new rear wings & the old boot with no problems. Today disaster, sprayed the 2 new wings ok with etch primer 2k but the old doors have reacted. Is it the old paint? Have I gotta remove all the paint back to bare metal? If so What's the best way to remove it? Orbital sander 60 grit ok?

 

[streetfighter]

Does look like a reaction to the paint underneath, either get the new paint off and smooth and use a sealer, or get it all off down to metal, orbital would be faster. 60 grit is a bit harsh might damage edges.

 

[Yoshi]

Got some 80 :tup: cheers

 

[henry's revenge]

Rub off the stuff you put on then put barcoat on it

U-pol Barcoat Quick Drying Isolator 1Ltr Upol | eBay

 

[henry's revenge]

See the problem is with bare metal is you would have to remove all filler and paint there may be on there if you leave the filler on as ive found to my cost the new stuff will react in circles round the filler

was it etch primer you used ? old etch primer and new etch primer dont get on

 

[farncombe pop]

You should not use etch primer on paint, etch primer is an acid that "bites" into bare metal ... remove the lot and start again.

 

[Grumpy Grandad]

I've had the same fault, it turned out to be the original paint and no matter what I tried to cover it with ( like barcoat) it still reacted. Unfortunately back to metal is the way forward.

http://i58.photobucket.com/albums/g243/truckdoctor/paint/P1030849_zps6f6a373e.jpg

Pretty sure it was down to synthetic (original? existing ) paint

Use these to get it off http://www.ebay.co.uk/itm/5-x-PAINT...Home_Garden_PowerTools_SM&hash=item58af8072e7

 

[Darren West]

you say you used something like bar coat

did you actually use bar coat

this stuff is a 100% isolator and i have never had anything able to bleed through the stuff

 

[Yoshi]

No I didn't use any barcoat, it didn't react on the filler/bare metal area. Spoke to guy whose gonna be painting it & he said strip it off with paint stripper back to bare metal

 

[Darren West]

yeah but this is what this stuff is designed for
do main prep then cover with bar coat then 3/4 coats of filler primer and as long as you don't go through the primer then all will be good

 

[Grumpy Grandad]

you say you used something like bar coat

did you actually use bar coat

this stuff is a 100% isolator and i have never had anything able to bleed through the stuff

Yes it was barcoat and used as directed, not successful.

 

[Dave'29Ford]

Get rid of the offending layer, you don't want an unstable layer in there even if it's temporarily sealed with Barcoat. Old paints like this continue to move move over time with heat etc.

 

[Ghostrider]

Never had a problem with Barcoat ,but as Dave said best if the offending paint is removed as any repair work at a later date will have the same problem

 

[D COUPE]

Like Grumpy Grandad says. A while ago ,early 9os, there was a paint product that was a cheap 2 pack. It was one pack poly (cheap shiny paint) and the powers that be
made it in to a 2 pack. Leyland and jaguar used it for a while.

Anyway it was crap especially if you came to paint over it. It never really went hard and when flatted it was just like synthetic.

This information is based on an actual experience not a search on Google!!

DC

 

[Yoshi]

Anyone recommend a good paint stripper? Last time I used some it would sting if you got any on bare skin but this stuff don't. What grade should I finish on bare steel? 80 or 180?