Respraying a metal amp casing

[ianrendall]

Just got hold of a GK 700RB. It’s in pretty good nick electronically but the top cover casing is pretty beat up (it’s nearly 20 years old). I’d like to strip it and respray it. Stripping it isn’t a problem, but what would you, the great BC unwashed, suggest regarding surface prep and paint to use? I’m not too worried about replicating the original factory finish, just want to make it look a bit neater.

[BassBunny]

I have repainted the top of a Genz and a MarkBass amp, but in both cases the top was removable. I used a metal paint "rattle can" from Aldi. It was specifically for metal and it didn't need any prior stripping or priming. I just sanded with an orbital sander until flat and then a couple of coats of paint. They still look pristine.

[ianrendall]

Yes, the good thing about my GK is that the beat up portion is completely removable, so no worries about spraying unwanted areas. I would probably do a chemical strip with a wire wool rub down to key the surface. The original paint seems quite thick so an overspray might show the lumps and bumps. I’m thinking a metal primer followed by several thin layers of a satin hammerite spray? I realise I may not need a primer, but the truth is, I love doing little jobs like this as I get a real sense of satisfaction, so I like to drag it out  

Edited November 9, 2018 by ianrendall

[fleabag]

Hammerite is pretty good stuff, and  plenty of choice re. finishes

[ianrendall]

It seems that modern retail chemical paint removers are useless, especially on what I think is powder coat. A few coats softened the paint enough for me to wire wheel it back to bare metal. A rub down afterwards with wire wool and white spirit, then a few light coats of Hammerite satin spray and it’s good as new

[gary mac]

Nice job. 

[Japhet]

It's really advisible to give bare metal a light coat of etch primer before top coating. The acid in the etch primer bites into the metal and the top coat then has something secure to fix to. Without etch primer you may well find that the heat and cooling of the amp casing in particular makes the top coat flake off easier. Most paint sticks to bare metal for a while and Hammerite is OK, but there's no substitute for a proper job. If the Hammerite doesn't work, don't try to paint over it or it will be a proper mess. It will need to come right off and start again.

[ianrendall]

16 minutes ago, Japhet said:

It's really advisible to give bare metal a light coat of etch primer before top coating. The acid in the etch primer bites into the metal and the top coat then has something secure to fix to. Without etch primer you may well find that the heat and cooling of the amp casing in particular makes the top coat flake off easier. Most paint sticks to bare metal for a while and Hammerite is OK, but there's no substitute for a proper job. If the Hammerite doesn't work, don't try to paint over it or it will be a proper mess. It will need to come right off and start again.

Yes, I forgot to add I used a primer first.