Cleaning Engine/Gearbox Cases

I know this is a common topic after rooting around a bit, but does anyone have a 'best' solution to cleaning the outside of the cases? Soda blasting seems to be the most popular to avoid tiny little bits ot glass/sand/shells lurking around inside somewhere. What thinks you?

Also, is there a diy system worth a hoot?

I've used naval jelly that's made for aluminum and steel wool to clean up some really grungy cases. You want to be up wind for this process but it works well.
Choose your steel wool by the finish that you are working on. On the polished outer cases use a very fine grade, a little coarser on the non polished ones. A few years ago I used this process on a set of inner and outer primary cases that I bought for $50 at a swap meet. They were straight and undamaged but were so nasty that they looked like the were covered in gray fish scales. After about a hour of naval jelly action and it was over to my home made polishing wheel. An hour or so on that and they were perfect.

I'm doing the engine block cases, so polished finish is not needed. What about boiling in simple green and water? Anybody tried this?

Soda blasting?

Naval Jelly has phosphoric acid as its main ingredient, a good acid to dissolve Aluminium Oxide, once it gets through that layer it then turns the aluminium in the alloy into aluminium phosphate which is a dark colour. So when using check it regularity and stop when you get the dark colour, caught early it wipes off, leave it too long and you need to use wire wool.

I've used a product called Super Clean. At one time called Castrol Super Clean. Works well on cases that are NOT polished and on Amal carbs though on the carbs use caution because it will stain the carb material if left to soak. On the rough Norton cases and heads there are no issues, rinse well though and use gloves as it will "tenderize" your fingers.
http://www.supercleanbrands.com/products#16

Dishwasher?

nickguzzi said:

Dishwasher?

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That could work too, as long as your wife doesn't catch you.

75/25 mix of kerosene and jeyes fluid or detol. Mix it together and it goes milky. Paint it on give it a scrub and rinse it off with water. The jeyes/detol makes the kerosene water soluble. Old trick but still the best/safest degreaser cleaner of aluminium I have found.

D

I've simmered over low heat Amal carbs in a lemon juice and water solution. Worked well and smelled nice. Read about this trick in Cycle World

BritTwit said:

nickguzzi said:

Dishwasher?

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That could work too, as long as your wife doesn't catch you.

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I thought dishwasher = wife ... ?

who ever is standing at the sink in my house .... I rarely pause long in kitchen once meal is finished ... I fellow once commented to my wife "while he was sitting at our table drinking black rum " ... that he was glad she knew her place , which was at the sink .... she hit him with wet dish rag several times ... have not seen him since ... :wink:
Craig

Dishwasher works but UK formula detergents contain phosphates and you get aluminim phosphate as a dark layer but you can,t control it as well as a bath of phosphoric acid. US may be different formula.

I believe I recall a past suggestion of simple green and scotchbrite pad. Worked pretty well for me several years ago. I continue to use the engine, so oil comes back then mixed with dirt. I just use some lacquer thinner on a paper towel to clean it off now.

I avoid blasting aluminum cases at all cost because it seems to forever change the surface finish, opening up pores that just collect more dirt.
I clean my cases in the laundry tub with hot water and some spray detergent and some nice stiff scrub brushes.
Maybe some WD40 and brass brushes for stubborn stains.

i used degreaser then alloy brightener on my ~BSA cases, it brought them up nicely, won't ever be as nice a soda blasting but theres also no issue with particles

I like to use the S-100 total bike stuff with a scotch bright pad then autosol solvo tube stuff ... lasts the whole season ... makes it look clean but leaves the evidence of being ridden for 40 + years , which I like
Craig

I just was watching Mick Hemmings video, he talks about "Vapor Blasting"...sounds like dry ice blasting to me, CO2 pellets, I think. I had some nasty old carts that were 20+ years old that had dried up adhesive all over them. I engineer adhesive coating processes on thin film webs - think putting 0.5 mils of PSA glue on 1 mil polyester film and making wide rolls of Scotch tape that get cut down to 1/2" wide later, but that is far more crude than what I am involved with. The dry ice blast worked great - even if what you want to remove is not hard - sand and walnut shells bounce off rubbery adhesive, soda leave behind high pH stuff I bet. Dry ice removed the long dried out, flexible adhesive, harder paint, and, I read recently, the dry ice process is effective at removing rust. Dry ice blasting = no metal removal, the CO2 evaporates, no scotch brite scratches (I like the no abrasive type - it is white what I got - I seldom use the really aggressive low grit stuff - far too much scratching), part is very clean after. Hemmings mentions some water weeping out when he heats up with a torch to remove the outer bearing races on the engine cases, most likely stuff trapped in the bearings , I dont know, but it made me think dry ice blasting. I am going to do that on my engine cases and see how she goes. The carts I did were not cheap, but for the business on a time line it was reasonable. For me personally on my nickle, I would shop it around and see what kind of a price I could get.

EDIT: Vapor blasting and dry ice blasting are different. Vapor blasting is a wet process, dry ice is dry ice - CO2. The CO2 particles sublimate on impact (going directly from solid to vapor phase,) this is reported to be like a mini-explosion at the surface that disrupts the surface contamination and looses and removes it.

If anyone has negatives, please chime in.

rockitdoc said:

I know this is a common topic after rooting around a bit, but does anyone have a 'best' solution to cleaning the outside of the cases? Soda blasting seems to be the most popular to avoid tiny little bits ot glass/sand/shells lurking around inside somewhere. What thinks you?

Click to expand...

I certainly don't have a better solution, but have removed a little oxidation and petroleum stains from aluminum and pot metal in my day.

I like dilute solutions of phosphoric acid (sometimes available as mag wheel cleaners in auto stores) for cleaning skanky aluminum. If you can’t find phosphoric acid in that form you can always swing by a farm & fleet type store and buy “milk stone cleaner”, which is a very economical means of procuring aqueous phosphoric acid. I’d use it at 5-10% active acid in water to start with. If you’re not happy with the progress you’re making you can always go more concentrated.

To start the cleaning process the cases need to be free of oil and grease residue to allow the acid solution to make intimate contact with the case. To clean the hydrocarbon residue from the case apply WD-40 (my favorite) or spirits and scrub hard with a stiff nylon brush or perhaps a stainless brush if residue is hard and caked on. Following this, scrub the case with a strong detergent solution to remove the solvent residue. In this state the case should clean well with the phosphoric acid solution suggested above.

As others here have cautioned previously, when using phosphoric acid solutions be sure the case is wet with water before applying the acid solution and remains wetted with the acid solution throughout the entire cleaning process. DO NOT ALLOW THE ACID SOLUTION TO EVER DRY ON THE CASE! Rinse generously with water between applications of acid solution to assure it is not etching something not in your immediate line of sight. Working in one small area at a time helps to avoid the foregoing circumstance. After a final and thorough water rinse blow the case dry with air.

Another cleaning alternative to the acid mentioned above, and one that is available at almost every auto store in the country (US anyway) is Bleche-Wite Tire Cleaner - a strong base that is likewise capable of dissolving aluminum. I’ve used Bleche-Wite with excellent results on Norton and many other vintage aluminum crank cases. All the caveats mentioned above apply to Bleche-Wite – start with everything clean and free of petroleum residue, wet with water, apply Bleche-Wite, keep everything wet during the entire cleaning process and don’t ever allow it to dry anywhere. Rinse generously and blow dry.

A final comment relates to Simple Green cleaner. I find this to be a superb product for removing internal engine smut from relatively clean parts, which does not dissolve aluminum like the above 2 products will.

Don’t mean to scare you with all the above cautions, just trying to assure you have a great outcome.

Please let us know the approach you take and the result you get.

I also got this stuff at Checker, or O'Reilly, or whatever they are called now called Eagle One Never Dull, use the google you can get it at Walmart, et. This is the USA, not sure if you can get it in other countries. Comes in a silver can, looks like old yellow attic insulation with polishing compound in it. I get a couple cans of that and as long as you aren't trying to degrease, or cut through a really thick oxidation layer it works pretty well. I had some bits that looked pretty much like replace or replate and came out nicely. I use it a lot on chrome and aluminum to see if what I have can be cleaned up or it needs re-plating or the polishing wheel for a more shiny aluminum finish.

Here's my plan since the results of this poll did not reveal an obvious 'answer'.

I'm gonna mix up some Simple Green concentrate with water. Pour this concoction into a big aluminum turkey cooking pan. Submerge my engine cases and boil this mixture of liquid and solids for a while on the barbeque while watching to see if anything untoward is happening. Hopefully, the aluminum vessel won't dissolve and ruin my nice barbee. But, it will result in squeaky clean surfaces ready to reassemble. Yeah, I've always been optimistic. :idea: A couple of Guinness's while posted as sentinel at the Q couldn't hurt, right? Since this is a science project, I probably should test different brews to see what the effect on the cases is, right? BTW, Fort Collins, CO has more brewers per capita than any where else on Mother Earth. At least that's what the Chamber of Commerce says.