Beginning to tear down my engine on my M20. The carb and clutch is dismantled and now I want to clean up the outsides.

What's the best way to get a nice, uniform matte finish? I have a bead blasting cabinet, but I'm worried that it will be too abrasive. I also have access to a soda blaster.

What's the best way? I don't want to mess it up! or leave a finish that will end up rusting.

Hi,
i would never blast it.
Recently i cleaned one with ordinary dish-wash soap, hot water and an old tooth brush. Worked well.

I always blast the carb...but it must be completely stripped to the component parts first...

This will give a finish as close to a new one as you will get...The soda blaster is probably the way to go as the soda is water soluble.

So, you can blast the parts, wash them in a little warm water and then blow them dry with an airline...This will remove all traces of the soda medium...

I don't have that facility so I run them through my blaster using glass bead and then thoroughly clean them afterwards by repeated washing and the application of the air line...

I've never had any problems with that method...in fact I did a carb the day before yesterday....Ian

email (option): ian@wright52.plus.com

Thanks for the feedback.

I'll give the soda blaster a shot today. Progress shots to follow.

Ian, if you do use bead blasting, do you run into oxidation on any of the cases afterwards or do you treat them with something?

Yes Steve I have come across silver lacquered carbs and also pre war BSA engine and gearbox casings. Try and remove that stuff if you dare!!!
I have found that the nearest modern equivalent is 'Simonize aluminium Wheel Silver' followed by that petrol proof matt lacquer from Swindon. Not sure how long it would last on a carb though. Ron

BEFORE

AFTER

email (option): ronpier@talk21.com

The Amal spec cards for the WD models generally state "Mixing chamber and float chamber lacquered'.

I have no idea why. Would corrosion have been a problem ?

Cheap and cheerful Chinese soda blaster, and a compressor with insufficient output, but pretty nice results....

email (option): teladelujo@msn.com

Some updates:

The soda blaster was a nightmare. Cheap Harbor Freight crap broke almost instantly. Got it working again today and didn\'t do too well. I ended up beadblasting and then finishing with a scotchbrite pad and steel wool. Seems to have come out really nice. Had to work out some pitting.

Clutch cover before:


After:

Hi Brian...If you don't mind thoroughly cleaning the parts 'post' blasting use a 60-80 grit aluminium oxide before finishing with a glass bead...hat's the combination I have always used...Ian

email (option): ian@wright52.plus.com