Hello. Ive asked this question locally but thought I would also put it too the m***es! I have removed all the paint and primer to bare steel on my 50 Shoebox. What I now have is a slight pitting on the surface which I have treated with phosphoric acid. It (the rust)has turned black. How far do I need to go in removing this staining? Can it be primered over? Will it come back? Any examples? I have tried various methods to remove and the best so far has been a flap disc moved quickly as to not cause heat in the panel. [/img] Andy.
Be carefull sanding out those pits.You could end up with some very thin metal.If you have cleaned with acid and nuetralized I would'nt be afraid to prim with epoxy.JMO
I use Rust-Mort, its a converter like you used. After it has done its process and dried, I wipe down with a water damp rag to remove any left over sticky residue, and blow dry with 'clean air' ( I use a turbine). Then I spray the entire area or panel with an etch primer. I follow up with body work and urethane primer as needed. Lots of ways to do it, this is just what has worked for me for many years. Saw a car the other day that I completed right at 10 years ago and it looked great!
Thanks. You are definately telling me want I want to hear but the engineer in me is screaming to remove all traces before I put it in primer. Building it as a shiney car so the last thing I need is rust comming up though the paint. I definately agree that removing it will/may thin out the metal too much. Anyone got historic examples of painting over this type of thing? Thanks again. Andy.
Andy , Call Tergo indusries they are in Rosebank Road... speak to the technical manager, he is very experienced in this stuff.... forgotten his name... sorry. cheers CC8
If your engineer instincts tell you to remove all traces of rust, why did you bother converting the rust in the pits? It just makes the remaining rust harder to remove. Ospho, the same type of converter, is made to be painted over.
On my builds, I strive to clean out all the dark stuff in the pits of the metal. If it's a small area, I use a spot blaster. If it's large and I think a good sandblasting will not do harm, I do that. On delicate areas (large flat panels, or possibly thinned out metal) I usually just spend a lot of time scrubbing the areas with something like Metal-Prep (a phosphoric acid solution from Dupont) or Picklex. Eventually using Sctotchbrite pads, steel wool, or a wire brush, the acid will dissolve all the rust, even in the pits, leaving clean "white" metal. Just don't try soaking overnight, or anything like that, theacid can completely eat away even the good metal. Be sure to rinse or neutralize when finished! (PS, not real crazy about using rust converters on the outside of cars, under nice paint!)
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