Cleaning up pistons
 

Hi. Well into my first attempt at complete engine rebuild from our 94 964.

I have been very reluctant to clean up any engine parts with my bead blast cabinet for fear of allowing tiny amounts of the media inside the engine.

I was trying to clean up the pistons with a wire brush...not likely...the blast cabinet would make short work of this and I found some references detailing masking the skirts with tape and cleaning the piston top with the blast cabinet...

Any experience or comment?

Thanks for the help

Gary

Once the face is clean what have you resolved? You need to use a broken ring and clean the ring grooves to install new rings. scrape the head gasket recess so the new lays in without carbon.
Bruce

If you are worried about glass bead, heat the pistons to about 180 in an oven and apply Easy Off oven cleaner. You may have to do it twice but it will restore the piston to "like new".

I was a little worried about it at first as well. But I decided to trust the folks on this board and use the experience of those guys that have already done it. Once I finished all six of them, ran them through the dishwasher, came out very nice. I am not anticipating any problems.

Wd40 soak for a few days, most comes off with a little scrub. Repeat a few times if necessary and they'll look like new and not caustic.

WD-40 works great as a degreaser on all the nasty stuff.

I think I used Permatex gasket remover. Applied a few times and let it sit for hours each time.

I'm tempted to try out my carb dip bucket... acetic acid. I have a couple junk pistons I'll test on and report back.

6 individual tin cans. 1 piston, top down per can. Pour enough lacquer thinner in each can to raise the level above the ring lands. Soak overnight. Fine scotchbright pad lightly on the skirts and piston top, dull razor knife blade as scraper for the crusty bits, toothbrush for the ring lands. Dip your scotchbright pad and toothbrush in the thinner to keep things wet while cleaning. Put them back in the cans overnight again to soak if required. Final rinse with starting fluid. Dry with compressed air. Light coat of WD40 as preservative.

The most difficult part is eating 6 cans of Sweet Sue chicken and dumplings or Dinty Moore beef stew beforehand.

I use baking soda blast in my blast cabinet followed by a good hot water rinse and then coating with Gibbs.

I've had really good luck over the years using the caustic carb cleaners with the dip basket as Lapkritis is referring to. Carbs are aluminum castings with lots of brass parts, so I never worried about harming Pistons.

Thanks guys, I tried the good stuff carb cleaner bucket as I had some on hand already. I was skeptical chemicals alone wound get the job done, when I hit the first piston top with a brush I found the carbon to be hard as nails and 1mm thick or more....anyway the Berrymans worked well with a overnight soak.

I know this is probably late, but a brass wire wheel on a bench grinder and then use a piston ring groove cleaner to clean the grooves out. This has become my standard way to clean pistons. The Carb chemical cleaner in a can works but you can only do 1 at a time with the gallon can.

I've use brake fluid with good results....

Aren't carb cleaners usually solvent based?
Caustic cleaners (sodium hydroxide aka caustic soda based) attack aluminum.

I think most of the solutions used to clean will do something to the aluminum when used excessively. I soak items for weeks at a time in the carb bucket and no issue. You can also used apple cider vinegar in an old coffee can.

Paint stripper works well having used it many times.

Use a wooden popsicle stick to scrape the metal so that it does not mark or gouge it.

I spent a long time searching out cleaning aluminum aggressively, and always found those stating this or that will cause damage to the aluminum.

I used all types of stuff that I didn't need to use.

Good ol' naphtha that traditional parts cleaners use works just fine and does nothing to the aluminum AFAIK.

X2 on the paint stripper, aka methylene chloride. Get the heavy duty aircraft stripper, brush a heavy coating on and then cover with saran wrap and let it sit. The saran wrap keeps it from drying out and lets it work longer. Follow the safety precautions, it's nasty stuff. I'd like to try Henry's method but use the barbecue.