Good News/Bad News v2.0

[bhn22]

I just bought an H&G 68BB 2 cavity San Diego mold! It is a bit rough, but should be serviceable once I get it clean. Okay, the good news is out of the way. Now the bad... It had mold prep poisoning. Yup, somebody too a hand made mold and buried it in mold prep. Acetone isn't impressing it, Brake Cleaner ain't doing it, and I'm about to buy a quart of paint stripper the free the inner mold. Mold prep is so thick on this one that I had to scrape the outside of the blocks with a razor blade to be able to read the markings, they were almost totally filled with mold prep. The vent grooves have the same issue. Any suggestions before I spend twenty bucks nuking the mold prep? I've never had mold prep resist acetone before.

[tomme boy]

Carb cleaner

[btroj]

Would an ultrasonic and some hot, soapy water do anything? Maybe something like simple green?

First thing I would try is a toothbrush and some Comet.

[geargnasher]

Sometimes denatured alcohol will cut things that acetone/mek won't. Permatex Aviation form-a-gasket is one example.

Gear

[rockrat]

Carb cleaner, berrymans b-12 to be exact. Alcohol, ether, acetone and mek iirc. Use in well ventilated area!!

[bhn22]

I'll try it. I need injector cleaner anyway.

Thanks!

[aap2]

Be sure to wear eye protection when you spray the mold; for some reason the nooks and crannies of the mold blocks seem to re-direct the solvent stream right back into your face....no need to ask me how I know this. good luck

[tomme boy]

See if there are any Hi-Performance engine builders in your area. If they rebuild carbs, they will have a dunk tank of the carb cleaner. I don't think injector cleaner will do it. Get a can of carb cleaner. Also, wear your safety glasses. It burns like a mother f'er if you get it in you eye.

[bhn22]

Well. It's soaking in Kroil right now. I did spray the outside with Chem-tool (Berrymans), and it still resisted removal on the outside of the blocks. A closer look tells me that the mold had probably been packed in grease at one time for storage, and that grease hadn't been completely removed before somebody tried to use it. So I have what appears to be baked on grease with mold prep over it. The dunk in carb cleaner sounds like a hell of a good idea right now, we'll see what tomorrow brings. I always seem to get interesting antique molds, this ones probably a 1941-42 era. This one has no serial/invoice number. After chasing my tail on the Ideal 429422 mold for months, I'm ignoring this particular issue for the time being.

[largom]

I would boil in soapy water first then carb. cleaner.

Larry

[Charlie U.]

Engine block cleaner. The thick foamy stuff that cuts thru all the gunk and crud on old car motors.

[tomme boy]

That is just diesel fuel or kerosene fuel in a can.

[USAFrox]

I know that brake fluid will strip paint (don't ask me how I know this). Maybe you could soak it in that?

[btroj]

Bring it to Bellevue and I will clean it up. Heck, I will even test cast a few thousand bullets to make sure it works.

Yep, I am that kind of guy.

[MtGun44]

old fashioned carb cleaner or paint stripper. Might take oven cleaner.

btroj - going to be in your neighborhood for a Swiss Rifle Awards Dinner next
Sat night. You don't shoot Swiss Rifle do you?

Bill

[btroj]

Nope, never got into that at all. I will be working Sat night anyway. Too bad, would be good to meet you.

Stop by walgreens on Galvin rd after dinner, I will be there from 3 to 10 in the pharmacy.

[bruce381]

stop screwing around and get some epoxy/marine paint remover will not hurt metal but will lift about any coating.
this is the thick stuff that you brush on and it lifts or bubbles the coating off I have not found any paint/baked on coating that this will not remove given a few coats
also wear gloves will hurt hands

[SciFiJim]

I will watch this with interest. How about some before and after pics. It is always interesting to watch someone clean up an old item that someone else tried to ruin by not thinking things through.

[Tonto]

Might need to move this to the powder coating thread....sounds like it was dipped in liquid plastic

[bhn22]

Carb cleaner was only partially successful. The petrified grease seems to be the real issue now. I haven't looked at it yet today, but I think aircraft stripper is in it's immediate future. So far, only light exterior surface rust, covered by petrified grease, covered by mold prep. I should have taken "before" pics. I didn't figure this project as being potentially educational.

[tomme boy]

If you are going to go the stripper route, go to a local body shop and see if they will coat it for you. They might do it for you for cheap, or a couple of dollars. Better than having a gal of stripper that you will never use again.

[MtGun44]

Oven cleaner.

Bill

[Reg]

This may sound crazy but give it a try if nothing else works.
Put in a heavy plastic bag and cover with a heavy dose of stronger ammonia. Let sit 24 hours but pick up the bag and slosh around the ammonia every couple of hours.
Was told about this in relation to cleaning old stoves that had the tops etc, covered with thick backed on grease. May take a couple of go arounds but it cleans old stove top to a bright new condition.

[hiram]

I got a mold squeaky clean by soaking it in a hot bath of TSP -- trisodium phosphate. This is the stuff you use to get all grime, grease, grit, and dirt off the garage floor before you paint it. Home depot. I bought the powder, not the premixed liquid.

[bhn22]

Oven cleaner.

Bill

Ohh, ohh... oven cleaner! Bill, you're a genius! How did I forget about oven cleaner?

[cbrick]

Sometimes denatured alcohol will cut things that acetone/mek won't. Permatex Aviation form-a-gasket is one example. Gear

Yep, it's also one of the best ways to clean oil off a new mold with mfg. oil on it. Denatured alcohol cuts many things that other more common things do not and it leaves zero residue. Works even better if you warm it slightly.

Rick

[bhn22]

Well, I took the mold and preheated it in the oven at 150 degrees, then let it cool until I could just barely handle it continuously, then dropped it in a zip lock bag and sprayed oven cleaner all over it. I pushed the air out of the bag and let it sit for a few hours. The petrified grease all came off, but I still have some mold prep to deal with. Then I'll deal with its alignment issues. The sprue plate needs surfacing, and I have a couple of minor issues yet to deal with. It's in the oven again now, drying off to get the water out of the nooks and crannies.

[Echo]

It may be too late, but my recommendation is to take the blocks to a parts store and have them hot-tank them. That stuff is really bad soap, and heated to near-boiling, will take off dang near anything. NOT the carb tank - it is too tame. The real hot tank will eat up a carb body if left in more than a minutes or two.