By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

aluminium crank cases

All Topics | Latest Posts

Search for:  in Thread Title in  
gerry madden09/06/2017 15:45:36
140 forum posts
55 photos

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 ?

Gerry

Jeff Dayman09/06/2017 16:00:05
1915 forum posts
45 photos

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 Gilligan09/06/2017 16:03:10
avatar
16632 forum posts
724 photos

Gerry,

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.

MichaelG.

Involute Curve09/06/2017 17:33:22
avatar
337 forum posts
107 photos

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.

Shaun

Neil Wyatt09/06/2017 20:14:13
avatar
Moderator
18316 forum posts
718 photos
77 articles

I used my ultrasonic cleaning tank with a 'sensitive metals corrosion remover'. Not obvious from these shots, but it removed white 'bloom' as well.

before 2.jpg

after.jpg

Ian Skeldon 209/06/2017 23:36:17
489 forum posts
41 photos

DO NOT USE OVEN CLEANER,

and don't ask me how I know wink

ronan walsh10/06/2017 00:37:19
544 forum posts
32 photos

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.

thaiguzzi10/06/2017 06:26:58
avatar
698 forum posts
131 photos
Posted by Involute Curve on 09/06/2017 17:33:22:

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.

Shaun

+1. Wot he said.

There is no better finish.

Tim Stevens10/06/2017 11:37:22
avatar
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
It crumbles to a greyish dust
And most of all what you can see
Consists of Al two O three

Cheers, Tim

gerry madden10/06/2017 23:10:48
140 forum posts
55 photos

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.

Gerry

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
EngineDIY
cowells
ChesterUK
Warco
Eccentric July 5 2018
emcomachinetools
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest