PDA

View Full Version : Cleaning the Alu - Magic Formula?



pisten-bully
12-11-2010, 12:09 AM
Anybody have a "magic formula" for cleaning aluminum cases? I've been using Nevr Dull, followed by No 7 polishing compound. The Nevr Dull is pretty good, removes lots of the grime and oxidation, yet it's difficult to work around the small crevices, nooks, and crannies where the most grime and oxidation seems to accumulate.

I don't mind spending the time on the Indian, but in my business I also very occasionally need to rebuild the gearboxes for my machines and they also have dirty and grimy aluminum gearcases to clean up (I'm doing one now). Working on a gearbox now that's really discolored and I'm dying trying to clean it up... "time is money" they say!

So, if anyone has their own ideas for cleaning aluminum cases (non-polished) I'm all ears! thanks.

exeric
12-11-2010, 08:28 AM
Bead blasting gives the best results but you have an intense cleaning process to deal with before they are safe to assemble. I am currently doing a refresh job on my Excelsior motor and I don't want to glass bead the cases. I like to hand wash the cases with lots of dish washing detergent and a scrub brush. Dish liquid is made to cut through grease and does a good job of getting the superficial grime off. After the cases are clean, I use 'Eagle One Mag Cleaner' which is a light acid etch and cleaner. It leaves a nice finish on the aluminum but again; it's not going to get the cases as fresh looking as glass beads.

bmh
12-11-2010, 09:12 AM
After glass beading and washing with warm soapy water, I like to wipe the aluminum down with a clean rag soaked with WD-40. It evens out the look of the aluminum, protects from corrosion, and makes cleaning off the inevitable greasy fingerprints from assembly a snap. They come right off with a rag and a little more WD.

rwm
12-11-2010, 09:58 AM
american cycle fab in berwick pa has a 30 gal ultrasonic cleaning tank i sent him a set of cases to clean. after christmas i'll post photos.(case are not done yet)

Milrite
12-11-2010, 09:59 AM
Citrus based cleaners will take all the crud off. If used undiluted, it will lift any paint as well. Wash of with warm soapy water. First pass on the aluminium use "Autosol", a mildly abrasive paste. Then a slightly less abrasive, like tooth paste, then move on to the Never dull. The cotton type swabs dont work well on the rough casting surfaces. Mothers billet polish also works very well. The wd40 is the final touch to keep it all looking fresh.
Dont forget if you use any chemical based solvents to neutralize them after cleaning with vinegar and water..... but, you probably are not going to use poly stripper to clean your cases!!

fillibuster
12-11-2010, 11:52 AM
If warm water is good, why not hot water? What would be wrong with a large pot of boiling water with detergent?
I worked in a tranny shop when I was in the army, the guy had a cooker big enough for several auto trans cases. The chemical was "varsol", I believe, and it was hot, steamy hot. Still, some cases would not come shiny clean, some stains were apparently permanent.

Robert Luland
12-11-2010, 12:38 PM
Phil, I agree with you. When I glass bead a case, I put it in boiling water for about 15 minutes. Opens up the pours and hopefully gets any residual bead out. It also gets any remaining oil or grease out. I never did find a pot big enough for this process, so I welded up a 16 gauge black iron box for my cleaning device. This works fantastic on oil tanks to get out the crud in the back corners you can’t reach. I use Tide laundry detergent and boil the oil tank for an hour. Bob L

Red Fred
12-11-2010, 12:55 PM
When I lived in the Indian shop of Allan Forbes in Scotland, we used a Vapor Blast machine on alum. It was very much like a bead blaster, but carried the media in a liquid, instead of just air. The result was a fantastic "sheen", which was way more appeasing than any factory product. Perhaps "over re-stored", but it sure looked great in the right application.
We were sure to boil out the part afterwards, and use the glyptal to seal in any microscopic abrasives that may have lingered. Plus the glyptol (electric motory insulation paint) helped seal the cases from being stained from the inside out, and repelled oil from clinging. The liquid did away with any dust, and limited the usual maladies of regular bead blasting, and it's lethal residue that gets impregnated in the alum. We baked on the glyptol also, as is standard proceedure.
As for a cleaner to use on restored-running bikes, after the build. Well, I'm still at a loss. Carb cleaner in aerosol form works for me (I'm lazy), but it is harsh on everything else. Therefore, I don't tend to maintain my stuff too well once it's running!
RF.

fillibuster
12-11-2010, 02:38 PM
Phil, I agree with you. When I glass bead a case, I put it in boiling water for about 15 minutes. Opens up the pours and hopefully gets any residual bead out. It also gets any remaining oil or grease out. I never did find a pot big enough for this process, so I welded up a 16 gauge black iron box for my cleaning device. This works fantastic on oil tanks to get out the crud in the back corners you can’t reach. I use Tide laundry detergent and boil the oil tank for an hour. Bob L

Sounds like my hallucinations haven't been so irrational! (my buds often accuse me of being on drugs) ... Thanks!

rousseau
12-11-2010, 11:23 PM
although this artical is about "carbs" , this method will work for your aluminium cases

http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/

jim d
12-13-2010, 07:07 PM
I have replaced the glass beads in my blaster with walnut shells at times to use on carbs and on original aluminum castings. The shells do a nice job of cleaning without removing machining marks and do not leave the all white somewhat rough finish of glass beads,which picks up finger prints and dirt. Your castings will retain the smooth to the touch finish as original. I have taken untampered with aluminum castings from a Indian and cleaned one well by hand with lacquer thinner and a small stainless steel brush. The rest of the part were blasted with shells. We could not see or feel a difference in the parts when they were placed side by side. Jim D

ricmoran
12-14-2010, 01:35 PM
Degrease with GUNK, then follow up with an alkaline cleaner like Joy dishwashing solution. Then a soak with ENVIROKLEAN whch allows a phosphotising of the surface without damage to the aluminujm. Rinse again with potable water and a neutralize cleaning with Joy or an alkaline soap to bring the surfaces back to base pH.

If there remains stains after this process, repeat the process with the last 2 products.

No surface blasting is required and the cases look like they were just made.

For light duty cleaning the ENVIROKLEAN can be diluted with water to slow the process if required.

Rich Moran18043

pisten-bully
12-14-2010, 02:05 PM
Thanks for all those ideas! I decided to try the soda blast idea presented by Rousseau, and it was a good one. Here's a before and after of the case I just did for one of the machines we sell (I know it's not an antique bike, but I would rather have experimented on this than the Indian).

A couple of things, the before shot was actually after using Nevr-Dull which removed a lot of the staining. The photos don't show it all that well, but before the soda blast the case still had deep staining in it and the soda blast did wonders. Only problem was I ran out of baking soda, after one trip to the store for more soda, I ran out again! But in natural light, not with a camera flash, the soda blasted case looks so much better, no staining is visible.

I've convinced myself that I saved hours of scrubbing with detergents or other liquids, some of which are not too good to breathe.

rwm
12-30-2010, 12:01 PM
i sent some case to american cycle fab. in berwick pa to be cleaned bead blasted lightly and ultra sonic tanked.i'm having some repairs done to the case's. so i they need to be clean for welding.i scrubed and boiled them. don't waste your time. boiling may have removed some oil but it left barnacles on the case. while they boiled little bubbles came out of the aluminium and left barnacles.so i sent them out. american cycle fab has a 30 gal.ultra sonic tank so the can do sporty cases. here is how they look.before i started and after they finished and the price was fair
http://i372.photobucket.com/albums/oo162/robronky/anzani/IMG_5716.jpg
http://i372.photobucket.com/albums/oo162/robronky/anzani/IMG_5719.jpg
http://i372.photobucket.com/albums/oo162/robronky/IMG_3290.jpg

rwm
12-30-2010, 12:07 PM
http://i372.photobucket.com/albums/oo162/robronky/IMG_3286.jpg