|gerry madden||09/06/2017 15:45:36|
|140 forum posts|
Hi, I have some aluminium crank cases from a small engine that have been in a damp environment for a few years and have developed that patchy white dusty coating.
I'm sure it will rub off with a bit of effort but I'm just wondering if there is a much more efficient way of cleaning these things up without leaving abrasive scratching marks in all different directions ?
|Jeff Dayman||09/06/2017 16:00:05|
|1915 forum posts|
You might try a motorcycle engine repair shop for glass bead blasting. It will leave a nice clean matte finish on your aluminum and not mar any details or leave scratches.
A coat of good clear car wax afterward, or some clear urethane spray clearcoat on outer surfaces, will keep the parts looking nice. JD
|Michael Gilligan||09/06/2017 16:03:10|
16632 forum posts
The best way that I have found is to use a GaryFlex block [which is rather like the old school 'ink rubbers'], with Solvol Autosol polish as 'lubricant'.
Yes, it's abrasive ... but very mildly so.
|Involute Curve||09/06/2017 17:33:22|
337 forum posts
I vapour blast all my crankcases as a matter of course, the finsih is as new, but you must make sure you clean all oilways etc afterwoods.
|Neil Wyatt||09/06/2017 20:14:13|
18316 forum posts
I used my ultrasonic cleaning tank with a 'sensitive metals corrosion remover'. Not obvious from these shots, but it removed white 'bloom' as well.
|Ian Skeldon 2||09/06/2017 23:36:17|
|489 forum posts|
DO NOT USE OVEN CLEANER,
and don't ask me how I know
|ronan walsh||10/06/2017 00:37:19|
|544 forum posts|
I boiled up some old cases in water with normal washing powder in it, the cases came out like new. But i tried it with a separate set of case sometime later, and they came out a blackish grey colour, not nice at all. Someone said it was because of the silicon content of the aluminium reacting with the contents of the powder.
698 forum posts
+1. Wot he said.
There is no better finish.
|Tim Stevens||10/06/2017 11:37:22|
1271 forum posts
Ronan is correct - some Aluminium alloys contain a high proportion of silicon, and when the Al is eaten away (by eg washing soda, or worse, caustic soda) the Si is left as dirty smudges. This is a major reason why anodising does not give good results on such alloys.
Aluminium does not rust
|gerry madden||10/06/2017 23:10:48|
|140 forum posts|
Well as usual some great info there. I didn't know about vapour blasting did some research and I'm impressed ! What's more there's a small business not far away from me that does it so I'll be visiting them next week. And by the looks of it, there's quite a few more bits and pieces they can do besides my crank cases.
Thanks all for your input.
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