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littlejimmy12
05-05-2011, 08:30 AM
just finished respraying the engine casings and then lacquered and its started to bubble

anyone know the solution to getting round this?

its been sanded back twice and is still bubbling on the 3rd attempt - I presume its the low cost Halfords high temp paint?? it was very well prept prior to painting.

LJ
Dookbob
05-05-2011, 08:38 AM
Did you get all the old paint off before respraying, I have had the same problem that you decribe, and I find that you need to get back to absolute bare metal, even a speck of old paint will create a bubble. Anther thing I learned the hard way is dont use a finish that requires laquer. Having said that, next time I refinish an engine case I am going to just rub down, then prime with one of these BAR coats that are available, aparently you can spray any kind of paint on top of the bar coat with out a reaction.
Kato
05-05-2011, 09:02 AM
Dookbob is spot on it will be a reaction to something (old paint ?) still on the parts.
littlejimmy12
05-05-2011, 09:39 AM
so its a rub down to the metal and try again aaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhh can't face that again, might just live with the bubbles....may be I can pass it off as a feature!
Funkatronic
05-05-2011, 12:21 PM
You could try this guy (http://http://www.icmhome.org.uk/)
He11cat
05-05-2011, 12:50 PM
Dunlop is good with advise on paint .. youve got a reaction going on there.
you can get a barrier coat.
you undercoat with that and it stops the reaction.

I would also avoid using a paint that requires laquer due to heat and also some tend to yellow... which looks a pig on silver casings.
a7avenger
05-05-2011, 04:30 PM
High temp paints need to be heat cured before they are resistant to solvents, that includes Lacquer.
I'd use Nitromors to strip them off.
What colour are you doing them in?
Pomp1
05-05-2011, 05:38 PM
Some paint can also not be fully compatible with another brand paint
johnboy44
05-05-2011, 06:27 PM
Dont forget the dreaded silicone, if you spray WD anywhere near a soon to be painted surface you'll pay the price
swesty
05-05-2011, 07:01 PM
WD40 does not or ever has contained silicone, according to their sales blurb.


It will still bugger up a paint job though. Quality preparation and materials are the key not just any old tat from Halfords et al. For engine cases just the high temp paint is needed, I've never seen a high temp laquer, that doesn't mean they don't do one I just havn't seen or needed it.




Dont forget the dreaded silicone, if you spray WD anywhere near a soon to be painted surface you'll pay the price
dunlop0_1
05-05-2011, 07:04 PM
Dunlop is good with advise on paint .. youve got a reaction going on there.
you can get a barrier coat.
you undercoat with that and it stops the reaction.

I would also avoid using a paint that requires laquer due to heat and also some tend to yellow... which looks a pig on silver casings.

Like the lady said.
You just need to apply a neutral or barrier coat. I have always used one called barcoat (you need a gun or air brush though). Prep your paint surface, apply one coat leave to dry over night and away you go. If you have to rub it back at all then touch up any areas you rub through or your problem will re occur.

This is the stuff,

http://cgi.ebay.co.uk/BARCOAT-SEALER-ALL-PAINT-SURFACES-1lt-car-/280523107064?pt=UK_Body_Shop_Supplies_Paint&hash=item41507aeaf8