14 replies to this topic

[redfish0]

I'm respraying my car. Problem is, I am getting a nasty reaction where I have sanded through the old paint. I thought it was polish or something but I suspect it might be paint stripper. I have a photo here...
http://gallery98629..../p27205171.html

Am I right? If so, how do I get round it bearing in mind I've got until sunday to get the car finished and its my only running car so I can't go anywhere to buy something (out in the sticks).

Thanks.

[THedooBZ]

surely if there was paint stripper there then the paint would have dissapaered ages ago,
did it bubble like in the picture after you sanded and sprayed it?

if so it could need a wipe with white spirits or similar before spraying to remove any residue, grease etc.. from the bodywork.

[redfish0]

It bubbled after sanding and painting yes.
It was cleaned with thinners and panel wipe too.

[minidaves]

its the thinners in the paint your applying is causing festering of the old paint, sant it all back 2k primer it (start with a dust coat) the 2 more coats and then apply top coat

dave

[Woody]

OR sand down apply BAR COAT and then primer ,topcoat.

[syholl]

Definitely use Barcoat. Its not worth the hassle to risk trying anything else. Cellulose paint is particularly bad for this due to all the thinners in the paint.

A very light coat of Barcoat before you do anything else will stop any problems.

[Tom Sanderson]

if it continues to react you may have to take all the paint off back to bare metal, then spray it with etch primer and topcoat. i had one where batteryacid had been spilled onto the paint and had to take it back to bare metal.

[Paintman]

if it continues to react you may have to take all the paint off back to bare metal, then spray it with etch primer and topcoat. i had one where batteryacid had been spilled onto the paint and had to take it back to bare metal.

If he takes woodys advice and uses BARCOAT then the problem has been solved, the reaction will not appear again.

[redfish0]

I've found some of this Barcoat and its has done the trick.

Thanks everyone.

[redfish0]

The primer is taking for ever to sand down. It looks really uneven and pitted too.
Its not supposed to be like this is it? Does anyone have a close up photo of how primer should look after spraying?

Heres a photo of mine after some sanding.
http://gallery98629..../p27284668.html

Is it not thinned enough maybe? or is it something else?

[bert998]

The primer is taking for ever to sand down. It looks really uneven and pitted too.
Its not supposed to be like this is it? Does anyone have a close up photo of how primer should look after spraying?

Heres a photo of mine after some sanding.
http://gallery98629..../p27284668.html

Is it not thinned enough maybe? or is it something else?

looks far too thick to me. use more thinners.

[Paintman]

The primer is taking for ever to sand down. It looks really uneven and pitted too.
Its not supposed to be like this is it? Does anyone have a close up photo of how primer should look after spraying?

Heres a photo of mine after some sanding.
http://gallery98629..../p27284668.html

Is it not thinned enough maybe? or is it something else?

If the BARCOAT hasn’t done the trick then you’re doing something wrong.

BARCOAT is used straight from the tin DO NOT THIN it down.
Once it’s fully dried around ½ an hour or so you can then primer over the top of it, DO NOT SAND the BARCOAT before you primer over it.

I can’t see a photo of what your primer looks like, but you should be mixing it to 4:1 ratio.

[redfish0]

That photo is of the primer, not the barcoat and its the primer I'm having trouble instead with now.

4:1 you say... The paint shop said 4 parts primer, 1 part activator and 10% thinners. Sounds like they might have it the wrong way about and should be 4 parts primer, 1 part thinners and 10% activator.

Just so I have this right, if I had a litre of primer, do I add 250ml of thinners and then 10% of the total amount or just 10% of the primer?

[Paintman]

That photo is of the primer, not the barcoat and its the primer I'm having trouble instead with now.

4:1 you say... The paint shop said 4 parts primer, 1 part activator and 10% thinners. Sounds like they might have it the wrong way about and should be 4 parts primer, 1 part thinners and 10% activator.

Just so I have this right, if I had a litre of primer, do I add 250ml of thinners and then 10% of the total amount or just 10% of the primer?

The paint shop was right, 4:1 is 4 parts primer, 1 part activator and 10% thinners.
The 10% thinners is the overall measurement of primer and activator.

If you think that it’s to thick then just add more thinners.

[ed4ran]

You can get wrinkly paint from applying it too thick,
the top layer dries before the underneath and when the underneath dries it pulls the top layer together causing it to wrinkle.

Just one other possiblity.