Hi gang. I'm not a regular on the 911 board but I have a question for you.
I'm cleaning a 3 liter engine case for a client. The case was run through a parts washer, then blasted with soda. The soda did a wonderful job of cleaning debris/varnish/carbon off the case. All the sealing surfaces look fantastic and are very clean. However, the soda doesn't have enough bite to make the exterior of the case look pretty. although I'm pleased with the results it would be nice to make the case appear as new. Since the case, obviously, exposed to oil, I need to use an organic blasting media. Would walnut shells achieve the desired result of making the case look new without any potential damage to mating surfaces/bearing surfaces etc? If walnut shells aren't the appropriate solution, what do you all suggest?
Thanks for any input.

Picture: The insides of the case are clean. I'd like to see the ends/extrerior of the case look as nice. The soda won't achieve this.

Ben

 

Have the case tumbled in ceramic media.

 

Most transmission shops have a cleaner that is real effective. They put the case in a cabinet of sorts and it chemically washes it. I don't know the details how they work but they do work well. Old hot rodders trick - soak it overnight in a bath of liquid drano (drain clog stuff).

 

Wouldn't Drano react with the aluminum? I remember a professor back in the old days added some aluminum foil into some drano and the reaction was intense!

I know on a lot of restaurant equipment that have some solid backed on carbon, we use a product called Sokoff
http://waljanproducts.com/sokoff.htm
It can be reused and I believe safe for all metals.
Why I mention the products is because not only did it take the carbon off the pan that required a a sharp knife and brute force to get off but all the stuff the sokoff touched looked shiney and brand new afterwards, bright metal look.
Probably require and overnight stay in the chemical.

Not cheap but you can reuse the same batch a few times over.

 

My buddies at the diesel shop get Cascade by the pallet. They soak parts in it overnight. Pistons and aluminum parts come out looking brand new.

 

This is very good info, thanks everyone. The cascade seems worth a shot since its an inexpensive, at home test. The quick bit of research I did led me to believe the aluminum will react with Lye. This week I will inquire about local shops with large tumblers. However, I'm still a bit skeptical about media being lodged inside the case.

 

Gel or powder? Do they dillute it? Sounds like a neat trick.

 

Powder, and yes they dilute it in drums of warm water. They soak the parts overnight and they come out looking like new. I was suprised how well it works. They are using it on big diesel engine parts which are real nasty. They buy the stuff by the pallet load.

 

yea, the drano trick could be dangerous. I never felT compelled to try it and I like clean stuff. Might work on iron/steel as long as you rince with water. I still think a good trans. shop can hot-tank it for you.

 

Cool guys. I delivered the case to my customer, but will be getting it back to experiment on later this week. I will be trying the cascade trick. I'll post some pictures when its happening. I also stopped at our local Restaurant Supply company. They had a spray on chemical similar to the sokoff mentioned above. It is completely aluminum safe, cost 15 bucks. I'll be testing that as well to see how far a can goes and the effectiveness of the job. Thanks for the info everyone! I'll let you know how it goes.
I did find a local shop that would hot tank. cost was 50 for the case, extra for all the misc. parts. I was suprised to find they use Extra Strength Tide in their machine. something about not being allowed to use toxic chemicals anymore. That could have been a choice made by this particular shop, not Law. I didn't inquire anywhere else.

 

On more thing about soda blasting, it is a salt and will corrode brass, copper, and ferrous metal. And it leaches out of studs, Just clean real well after blasting. No problem with glass or shells.

 

After soda blasting, we put engine cases in our jet washer and everything comes out VERY clean. Other, less complicated castings or parts can simply be rinsed with water.

JMHO, but thats the best way to clean engine components as well as many other things.

 

In 20 minutes, Draino ate the chrome completely off of my metal bathtub drain. I wouldn't let that stuff near my engine parts or anything else made of metal.