Which primer for 2K spray paint on steel and/or aluminium frame

Nov 21, 2023

1k etch primers are k a k. Especially the crap you get in rattle cans. Its so thinned out and the chances of messing up your job is almost 99%. Get yourself something decent like Corrocoat 1 from Dulux. For spraying you need to thin with etch primer thinners otherwise it will just come out as cobwebs. Years ago when i used to spray aluminium trailers we used Corrocoat 2 which was a right pain in the ass to spray.... You couldnt spray it without a proper mask as the stench/chemicals was so bad you wanted to die... Imagine something close to mustard gas probably hahaha (Really good stuff but unfortunately or rather fortunately its not around anymore)

Anyway after the etch primer 1 or 2 layers of a good quality 2k filler primer, dont spray this wet or shiny. Mix 4:1 for best results. Once dry, sand this primer smooth as you can get it without going through to metal again. Normally around 600grit wet.

That should give you a good base to start the rest of your paintwork.

Thank you for the advise

I saw the Corrocote 1 Metal Etch Primer when I ordered these 2 etch primers: Glaker and Supreme, but at the time they only had the 5L units for the Corrocote. I do have some etch primer thinners as well. Have you any experience with these manufacturers above? I will order the Corrocote 1 in any case.

It's early enough in the job to strip the frame again, the etch primer on there is pretty soft and came off easily when I tried to smooth out the flaws. I'd rather start from scratch. I aim to use this frame as my future road-bike, thus want to do it properly. And everything rusts to sh!t in Cape town if not done properly.

How many layers of initial etch primer should I use, or should it be very thin - just enough to make sure I cover the steel, before applying the 2K primer filler?