cleaning up a diff. What to use?

[The Pikey]

I have a diff case I want to clean up so it looks "as new" I have a smallish compressor at home or a big one at work so I should be ok there but do I need one of those blasting cabinets and what's the correct grit to use for cast used for the diff?

 

thanks in advance

Jason

 

Currently, I am qualified to plead ignorance.

 

[Rob Walker]

Road and Race degrease and spray the cases with aluminium paint.

[Westfield]

A medium grad aluminimum oxide grit will clean it up a treat…. But, this leaves a very “open” surface which quickly corrodes and does not stay looking good for long. Oily or grubby finger prints are difficult to remove.

 

If you lightly grit blast it first then use a medium or course glass bead, this has the effect of closing the surface and the finish lasts a lot longer, especially if you spray it now and then with some duck oil or WD40.

 

Probably the best suggestion has already been made for something that sits under the car, paint it. For a really good long lasting job, a ligh grit blast, followed by a de grease and a coat of etch primer and topped off with a good coat of pain will last. If you omit the etch primer the paint will quickly peel, flake.

 

If you do blast it make sure that EVERY bit of grit is removed… it lurks in all the little nooks n crannies!

 

Not quite the same but there are a couple of pictures on the link below of a Lotus engine case that has been grit and then bead blasted and also a couple of some DCOE carbs that were bead blasted with fine glass bead. With these the key is thorough masking off to stop the glass bead getting into the insides! Fine glass bead is as fine as flour!

 

 

 

 

bead blasted cases

 

 

 

 

 

Edited by - Tony L on 10 Apr 2008 19:30:45

[JampJ]

As already mentioned, blasting will leave a fine pitted surface that soon fills with muck, and is hard to clean. Have you thought of trying a wire brush in a drill? If done carefully you can get a really nice smooth finish.

Cheers John

 

JFDI

(Just F*****g Do It)

[The Pikey]

Thanks for the ideas guys. I have cleaned up my diff with a wire brush but its net perfect.

 

Anyone know what process Mitchell Cotts use on the caterham diffs? They seem really well done.

 

Jason

[DaveK]

Jason

 

We had our bead blasted, then i etch primed then painted satin black, still looked like new 3 years later, and alot easier to clean than the alloy

 

Dave

[DohNut]

 

Agree with J&J that a drill and brush can get a really good finish, I used a "bristles out the end" type brush wiped it down with white spirit and then sprayed a can of clear laquer on it. It stayed pretty nice for several years

 

Nick

[The Pikey]

Is powder coating an option? or s it no good on things that have surfaces that bolt togeather?

 

If powder coating is not and option then I'll think I might go down Dave's route (so to speak 😳) and etch primer and paint it satin to match the rest.

 

Jason

 

 

Currently, I am qualified to plead ignorance.

 

[DohNut]

 

All finishes, paint or powdercoat etc should stop at the machined faces.

I was not doing a full strip of the diff so I sprayed the laquer when it was bolted together .

 

N

[Sheds Moderator]

I think this is a very expensive route for something that's underneath. I would use wire brushes until it was clean enough, then apply clear lacquer, silver paint or black to taste. You can degrot first with a paraffin gun and an airline, TBH I would favour this until clean then add a bit of oil to the paraffin, spray and walk away.