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Restoration - Suspension Parts - Should I Paint?
Posted: Sat Aug 21, 2010 3:36 am
by oilypaws
I'm working on the bodywork right now, and I'm planning to fully repaint it. It was parked under a hedge for a few years before I got it, and the suspension parts all have a bit of surface rust from the damp and lack of use, but I don't think it weakens them at all. Is it a good idea / normal / required to clean them up and paint them?
I'm thinking I could run over them with a wire brush to take the dirt and rust off, then perhaps some rust treatment like BlackGuard followed by primer and black acrylic paint from a spray can. Alternately, I could just wipe them with some oil since in my experience those parts tend to stay oily and therefore rust-free if the car is in regular use.
The U-Bolts on the rear springs are the only bits which concern me as they look a little too rusty on the nuts and threads. I might replace them.
Here's a pic of the back end of a rear spring to illustrate:
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Re: Restoration - Suspension Parts - Should I Paint?
Posted: Sat Aug 21, 2010 7:31 am
by bmcecosse
Entirely your choice - but black chassis paint is often used.
Re: Restoration - Suspension Parts - Should I Paint?
Posted: Sat Aug 21, 2010 10:26 am
by chickenjohn
Don't use "Blackguard" or whatever it is. Those rust so-called "converters" are basically rubbish. After thorough wire brushing and application of the "converter" let it dry and scratch the surface and you will find brown rust still there underneath. Oil won't last long as it is soon washed off in wet weather. Those methods won't last for very long. I've tried just about every rust converter on the market over the years and they only convert the surface layer and hide the rust for a while.
The best way is to remove all the rust and then protect the clean parts. I can see a few ways of doing this depending on time and money available:-
1. get the parts blasted and powdercoated black
2. Get the parts blasted and etch primed then give the parts a few good coats of chassis black.
3. Use wire brush on grinder/ drill and multiple applications of 10% phosphoric acid to remove all the rust, then prime and paint with chassis black.
Re: Restoration - Suspension Parts - Should I Paint?
Posted: Sat Aug 21, 2010 11:45 am
by oilypaws
Interesting - I have used Blackguard on quite a few bits already, and thought it was Ok. The inside of the floor has been done that way and then painted over with primer. Time will tell! I'll have to try scraping some off and see what adhesion is like and what is underneath.
Some bits - for example the sills - had been very rusty in the past and had been painted with something shiny and black which was very effective in stopping further rust. I wish I knew what it was.
Thanks for suggestions!
Re: Restoration - Suspension Parts - Should I Paint?
Posted: Sat Aug 21, 2010 8:27 pm
by bmcecosse
CJ is right - rust converter painted over surface rust is no use at all - but - it IS good if you (as CJ suggests) energetically wire brush off all the surface rust first - then apply the potion. It can then act on the little pores and pits in the otherwise clean/shiny surface and hopefully stop them spreading - for a while........
Re: Restoration - Suspension Parts - Should I Paint?
Posted: Sat Aug 21, 2010 9:23 pm
by charlie_morris_minor
with small parts electrolysis is a good method of getting rid of rust.. especially if you can leave them for a while and get on with other jobs..
Re: Restoration - Suspension Parts - Should I Paint?
Posted: Sun Aug 22, 2010 12:12 pm
by chickenjohn
Another best way of de-rusting small parts (I just remembered!), soak them overnight in a 5-10% Citric acid solution after wire brushing them clean. This will dissolve all the rust from the pits.
Then panel wipe the parts clean and dry and as soon as possible paint with etch primer and then chassis black when the etch primer is dry.