Whats the best thing for priming alu body

[Rick W]

As the title suggests, what is the best paint for priming an aluminium body with, and where can I get it from?

[sirhc]

Rick,

 

You need some etch primer. I get all my paint from Crosbie Coatings now, they're friendly, fast and not expensive.

 

http://www.crosbie-casco.co.uk/

 

Chris

[Grumpy]

As Chris said etch primer, but be very careful and only use in well-ventilated areas and preferably with a good mask. Most etch primers contain sulphuric acid and tend to sting a little when breathed in :shake: You can get it from any good paint supplier in aerosol tins. One thing to remember is when you rub down the primer, if you rub through onto bare alloy you will have to prime again as your top coat will just peal off.

[Rick W]

Thanks for the lead! We have used aerosol tins in the past just to prime the Morris panels, but even at trade prices doing the landy body would take a few crates of the stuff!

[Richard Notton]

As the title suggests, what is the best paint for priming an aluminium body with, and where can I get it from?

 

The very best stuff is two pack chromate etch (900), its the greeny-yellow stuff you see in alloy aircraft parts. You simply mix the base and acid 1:1 resulting in a watery mixture which needs lightly spraying and its sometimes quite difficult to see where you've been!

 

Unfortunately the dear EU has removed it from the market because it works brilliantly but they don't like the chromate bit, however, you can get it from the aero suppliers because its absolutely non-replaceable for aircraft. Light Aero of Shebbear in Devon will do it but its something like 60 quid + VAT and carriage for 5L.

http://www.northdevon.gov.uk/index/lgcl_business/nonlgcl_business_promotion_details.htm?businessid=CE51251F-4DC5-40D3-BA24-0070A1A1B362

A proper industrial mask is ESSENTIAL, the acid element will dry your lungs and choke you very quickly and the chromate element is probably nasty too, however, I have used the stuff daily for 2 years and haven't died yet.

 

From one of the larger, proper commercial suppliers you can still get two pack acid etch but chronate free (903) and usually grey, it is not quite as good but still heaps better than any single part "etch" primers. Try Chromadex. The biggest problem with this stuff is it is exactly the same colour as freshly blasted steel. . . . . . . . .

 

With both you need it to stand for 10 mins before use to activate and left-overs should be discarded after some 24hrs. Overcoat with regular paint in 24hrs too or adhesion will reduce.

 

 

[Rick W]

Thanks Richard, I think that explains the very thin yellowy looking paint that lies underneath the original coats of paint, we were wondering what that might be!