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MG Midget and Sprite Technical - Metal Finish

I have a diff unit which is bare metal and I would like to paint/finish so it looks tidy. I can clean it up to remove grease and debris but what is the best primer/paint combination or what ever to get a reasonable (not show quality requirement) finish that would be durable?
G Williams (Graeme)

If you do not have the correct facilities for 2K painting then try rattle cans of single pack paint.
You will need to etch prime first, just a dust coat, then a few coats of primer. Flat this back with 800 w+d paper then add 3-4 coats of top coat. It really is worth taking the time as the results can be very pleasing, and long lasting.
Here is an Escort axle in one of our Minors



J L HEAP

Would you use any of the Hammerite products?
G Williams (Graeme)

No, dreadful stuff. If you pay your local car body supplier a visit ,they will suggest the best route for you. It needn't cost a fortune either.
J L HEAP

X 2 graeme...sort of !!!

hammerite in a rattle can... its only $10 for a can, and very little mess and the best spray paint ive ever seen

get it in a quart or a pint...ahhh, I wouldnt that can be a bad mess really fast if your not carful

by the way... it will not come off skin once its dried, at least not for about 6 weeks...so follow the clean up instructions to the tee

prop
Prop and the Blackhole Midget

The catch line with Hammerite is that it will paint over rust. Well any paint will do this. Rust must be totally removed first then treated in the correct way. Simply applying paint over it, Hammerite style means you may well have a nice shiney top surface, but below this the metal is still rotting away.
The hard surface of Hammerite is also a problem as it chips very easily allowing watr to creep behind the surface layer.
Never use Hammerite or Smoothrite on the underside bodywork for the reason above
I suggest the original approach from 25 years experience in the bodyshop business.
J L HEAP

Go to a good paint shop they will sort it.
Mine has a polyurathane paint used a lot in farming and industrial use.
Perfect stuff!
Brush on and it flows very good so little to no brush marks are left.
And if it lasts on farm equipment it can't be that bad
Onno K

Hi Graeme

I assume you mean the ally diff unit and not the whole axle. I cleaned mine, primed it with etch and sprayed it with black gloss froma rattle can. It has been on the car for 3 years and still looks very smart
Bob Beaumont

Yes, just the diff itself. I'll try that but sounds as though I should avoid Hammerite!
G Williams (Graeme)

well ... JL makes a good point about the rust

what ever you do... the rust should be removed to do it the correct way

I wast aware that hammerite had an issue with chipping, so maybe onnos approach with the polyurithian paint is the better approach

gitting the rust off just the diff is going to be tough

if it were me... id do the entire axle...not just the diff...but thats just me

prop



Prop and the Blackhole Midget

The axle has been sorted. Only the diff body needs doing and it's rust free.
G Williams (Graeme)

I have to say, I've never had any problems with smooth Hammerite, although I don't apply it over rust!

Dave O'Neill2

What's wrong with hammerite then?
Lawrence Slater

I always think Hammerite gets a bad rep because a. it is widely available so morons that just want "some paint" buy it, combined with b. because it is advertised that it can be painted over rust.

As it is readily available, people who don't really "understand" painting buy it. No paint will last long when when painted on top of muck and grease and terminal rust. But people that go to the effort to source "posh" paint are more likely to clean the thing they are painting, prime it correctly etc. and so, magically (ha!) the posh paint lasts years. Whilst the bloke that painted Hammerite directly onto the filthy component is moaning that it didn't last 2 weeks.

Vica versa, give the idiot the posh paint, it won't last 2 weeks painting on a filthy component either.

They always say 90% of a good paint job is the prep. I think Hammerite would give a good a finish as any if the prep and priming is done correctly.

Malcolm.
Malcolm Le Chevalier

P.S. You don't need an etch primer if you have abraded the steel (assuming steel, not alu.) with some wet and dry immediately before hand. The abrading does the 'etching' for you.

Etch is for new, flat, shiny steel in car factories where they don't have the time to mess about abrading all the panels to get the primer to take properly.

That is my opinion stated as fact anyway, I am doubtless others will tell me I'm wrong.

Malc.
Malcolm Le Chevalier

Malcolm

Agree that prep is all important to what ever you paint the car with. Hammerite /Smoothrite will give a smooth shiny finish on most surfaces but is also intollerant of dirty,oily surfaces.
It does however have the downside of chipping, and in doing so has the effect often seen on off road vehicle nudge bars or side steps where only the powder coating
is holding the item in place.
If used on the underside of a vehicle its a nightmare to remove, and is not compatable with bodyshop paints, causing all sorts of problems.
Re etch, its really 'good' practice to always use on any bare metal as it gives a chemical bond to the surface and then re activates when the primer is applied.
Most modern car plants now E Coat their cars which does not require an etch coat, simply a top coat. The E Coat provides the anti rust protection, the top coat simply a colour finish.
J L HEAP

Years ago, the paint of choice for car underparts (and bodywork in some cases) was standard Valspar oil based gloss paint. In those days, and I think paint formulations have changed many times since then, this paint took hours or even days to dry. And when it did, it remained just slightly soft and pliable. So long as any rust underneath was removed properly, then this flexible paint would withstand a lot of mistreatment from stones, road salt and grit, without chipping.

I have also used Valspar for brush painting bodywork; attaining a high gloss and brush stroke free finish by applying multiple coats and flatting down between each. The end result would stand comparison with any spraygun applied finish!

I do use Hammerite, but I don't rely on its claim to be suitable to use over rust! It works well if you can warm the component in an oven first, and then also cure it in the oven as well. Smells awfull, and you won't be popular, but it helps the paint flow and seal better and it seems less prone to chipping afterwards.
Guy Weller

Thought about powder coating?
HALL JOHN

This thread was discussed between 20/03/2013 and 30/03/2013

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