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MG Midget and Sprite Technical - Painting chassis black parts

I've done this for years, although never been 100% happy with the results I achieve. And having done it for years, I am probably stuck in a time warp of 1970's renovation products. There must be something better by now! So thought I would see if I can learn from others.

I am refurbishing a pair of backplates and would like to get a gloss or semi-gloss black finish that is hard without being brittle. The other thing is that the surface, because it was previously rusted, has a roughened texture a bit like a sand casting. It has been electrolysis cleaned to bright metal so is ready for treatment and painting but how do I get rid of the pitted surface ? Should I use a filler primer, or is there something better nowadays?

And, I want something that is reasonably economical and can be done at home, so that rules out powder coating!

Discuss.

Guy W

I used a coat of etch primer followed by a couple of coats of primer. Then black top coat and finally semi gloss lacquer. It took out most of the pitting and has worn well over the last 3 years.
I considered using a filler primer to completely loose the pitting but that seemed a bit OTT.
Bob Beaumont

Guy,

Are you ruling out powder coating at home due to cost or because you think it can't be done at home.

See

http://www.mig-welding.co.uk/forum/showthread.php?t=25393

http://www.electrostaticmagic.co.uk/
David Billington

David,
Thanks for those links. I didn't realise it could be done as a DIY system. Videos and links are certainly interesting. Tempting, but unfortunately even the basic system at 179 is too high for me to justify.

Bob, that is along the lines that I would do. I have also tried Hammerite, but baked in an oven. It made it flow and obliterated brush marks very well and improved the curing. So that is still an option.

I was wondering about using a polyurethane 2K primer as I thought that might fill the surface irregularities better? Not tried that yet though.
Guy W

They make a bondo called "all metal"....its just like bondo but way tougher ... because its got metal particals in it

As to paint... maybe like I used yesterday

Automotive body paint ...acrylic enamal with half the hardener catalyst

My cly head is really curing well and has both a hard and almost scratch resistant shell

Ps... I found 2 coats of metal etching black primer did a nice job filing small pits and had a nice satin finish ...fairly decent hardness...just a thought

Prop
Prop and the Blackhole Midget

Hi Guy I specialize In getting all parts powder coated for midgets from brackets to axle casings and dashes rewrinkled to concourse condition. You can contact me on 01332 510130 or 07749838528 or email me at Richard.woolley@hotmail.com. Richard
rj woolley

Thanks Richard, I am still of a mind to paint, mainly because I like doing these sorts of jobs myself. I was just checking on whether modern science had come up with a better paint formulation on the last 30 years or so!

Not comparing to powder coating at the moment. But an ordinary good quality oil based household paint takes a lot of beating. I have also had some successes with Hamerite; if put into an oven before it dries it flows better and covers over brush strokes and hardens nicely. Downside is that in the longer term, Hammerite is a little more brittle than oil based gloss.

Don't really understand the ins and outs of Acrylics, Polyurethanes and so on.

Still looking for a solution to the "sand cast" effect that one gets on steel that has been pitted with rust and then cleaned with phosphoric acid, or by electrolysis.
Guy W

Guy,

Have you tried the pitch epoxy paints such as Rustbuster etc sell for chassis painting.

Its a two pack brush applied and has a terrific adhesion to bare and slightly rusty surfaces. Also extremely difficult to damage and a couple of coats will fill most surfaces
Can be overcoated - I've coated most of the underside of my midget with it and some suspension bits also.

R.
richard boobier

Hi Richard,
Not sure if this was the same stuff you are talking of. I have used a Epoxy-Mastic 101 2-pack paint from Rustbuster on the inside of my Frog rear wings. Seems pretty good in that application although I haven't tried overcoating it with anything and it isn't yet in use.

I will take a look at their other products.
Guy W

I was looking at this new product from Frost, available in black as well.

http://www.frost.co.uk/liquid-wrap-matt-flat-aluminium-aerosol-400ml.html

Looking at the pictures it would take out the ripples.

Shaun
Shaun

Shaun, I saw that but couldn't quite understand what it was about.
The photo - and there's a video too - show it being applied and the peeled off again in a sheet; the original good paintwork remaining underneath. So rather than being a primer for smoothing out irregular surfaces, it looks like a temporary rubber coating applied to protect parts.
Guy W

Guy,

Yes that is the Rustbuster product - think its code 121 that I used - tough stuff, need good ventilation when applying.

R.
richard boobier

Ah yes, 121 - that is what it says on the tin. As you say, the fumes are pretty strong!
Guy W

A couple of years back I built a 30's style 2 seater out of a Citroen 2cv. I painted the chassis with POR 15 and it peeled off. I did not use the prep liquid. As the chassis was galvanised I left it as it was in the end. I have used PoR elsewhere and it is brittle, horrible to clean and fades if in the light. Hammerite is also brittle. I have had a lot of success with Frost Chassis Black paint. It gives a high gloss, good adhesion and easy to clean. It may be no better than a good outdoor black gloss though. Ihave no experience with 2 part epoxies so can't comment. As to primer, my friendly body shop says to use either etch primer of red oxide. Ordinary primer will not key into the metal. Hope this helps
Walter
W Clough

Thanks Walter, I think I will try that Frost chassis black. I always use an each primer anyway. Just wondered if I would need a filler primer as well to smooth out the pitted surface.
Guy W

This thread was discussed between 27/08/2013 and 07/09/2013

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