sheet metal pitting

jr1983 · Nov 23, 2016

I have an MM UB. I'm going to try my hand at painting. The hood is in decent shape but it is pitted pretty bad. What do you do about this? I know very little about painting but I can't possibly hurt its appearance. So I'm gonna try.

Stephen Newell · Nov 23, 2016

If you want it to last you strip it down to bare metal and either sand blast or treat with phosphoric acid and then to prevent it from rusting again prime it with an epoxy primer. From there you can fill in the voids with a fiberglass filler of if the pitting is minor fill it with a filler primer. Once you get it level if you have sanded down to metal again then prime it again with epoxy primer. Then you could wet sand and topcoat or use a filler primer again if you wish to dry sand again.

Metal just has a tendency of rusting underneath the paint and the epoxy primer will stop that. Also with other primers if you get a scratch to the metal the rust will grow and spread outward under the paint where with epoxy primer the rusting is isolated to the scratch.

FBH44 · Nov 24, 2016

What Stephen said. Rust of iron / steel starts, and the rust burrows down, and pits, and is almost impossible to stop. The pits will somehow absorb tiny amounts of surface water, and start rusting and erupting rust again. The iron oxides of various kinds absorb more water, and start rust again, as they try to form more stable forms of iron oxides. Do all you can to stop it and seal off the pits. Best of luck. Keep it out of the rain and weather and cold and fog and dew.

dr sportster · Nov 24, 2016

two part filler putty [ dolphin was one brand] no shrinkage

JohnAndrew · Feb 4, 2017

I had good results stopping rust with a product called Rust-Mort. There are two types, one that does not require rinsing and turn the surface and the rust to a hard black paintable surface. the other has to be rinsed and will only turn the rust to a black. O-reilly's can order it for you, they don't keep it in stock , Rust-Mort # 69508

BushogPapa · Feb 5, 2017

I don't care what you are intending to paint...but I would remove every speck of rust I could...and then maybe hope for the best..

Sand-Blasting is a good way to clean all rust..other media can be used too..

Those rust converters will slow deterioration ( Rusting) when applied if the scale is removed and the surface is dry when applied, but

I would ONLY expect it to slow the rust..and it does that pretty well.

sheet metal pitting

jr1983

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Stephen Newell

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FBH44

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dr sportster

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JohnAndrew

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BushogPapa

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