I just was given some moulds from a friendand some of them have a little surface rust[rcbs moulds].How is the best way to clean them up.I remember someone posting about using a home made reverse plating but can't find the web site. Can any of you guys give me any advice.

Are you trying to remove rust from the outside surfaces; the sprue cutter; or the mold cavities? If the first two, soak the molds in WD-40 for a few days, then use 0000 steel wool or 600 to 1000 grit sandpaper to remove surface rust. While you're at it, remove each sprue plate, place it on 400 grit sandpaper wet with WD-40 or mineral spirits on a hard, flat surface and rub in a circular motion until shiny. Finish up with 600 grit. (This is called a surface grind.) If the cavities are lightly rusted, a clean phosphor bronze bore brush of the appropriate caliber (never stainless steel) or a smaller brush covered with 0000 steel wool chucked in an electric drill will work. Degrease the cavities with your favorite solvent if your going to cast soon. If not, use something like WD-40, Kroil, ATF to keep them rust free.

I had asked the question last year about a badly rusted Saeco 4 cav mould and was refered to a web site that described the method. I am at work right now so don't have access to my files but will post the site tomorrow. If it is very light rust in the cavities pencil erasers work well. My Saeco mould was heavily rusted and cleaned up great with the electrolytic derusting. Nick

My 60 year old brain still functions!!! Rememberd stovebolt. Here is the addy http://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm Good luck Nick

fecmech,

I too have a badly rusted 4 cavity Lyman. The 452460 and I really like shooting those. I'll be really interested in the data on electrolytic derusting.

Thanks guys for the info

Dave,

Here's another site you might want to check out. It goes into a little more detail.

http://www.fboerger.com/electrolysis%20story.htm

Mike

Thanks to both of you. I'm going to give it a try.

What about this 'site? I found it after reviewing the first one.
Using Molasses for Rust Removal!

That has got to be the dangdest thing I ever heard of, even if it DOES take a week or two!>>>>Bug.

Both of these are old hat to those of us restoring old engines and tractors. They work equally well. The molasses method takes longer and smells pretty funky as the stuff ferments. We've argued a lot about the chemistry, but I think it's organic acids produced by aerobic fermentation of the molasses that do the derusting.

I've got some rusty moulds I've got to clean up, too. I've been trying to decide which method to use. With cold weather coming on, the electrolysis may get the nod.

[ 11-20-2003, 21:48: Message edited by: NotRicochet ]

Dave.
Give it the Navel Jelly treatment if you can find some. While visiting a friend last year, in his shop was a extremely rusty 358311DC that was left out during a flooded basement stint. He said he was going to throw it out, so it followed me home. I wiped Navel Jelly on it with a toothbrush and let it sit for an hour. Some spots had to be redone a second time. The jelly takes every bit of blueing off, and it leaves a temporary rust inhibitor on it untill you oil. It takes a bit getting used to seeing the color missing on the blocks, but after three casting sessions the blue color came back by itself. I'm guessing Navel Jelly is still available at hardware stores, cause the jar I've got is at least 10 years old...Geo

I've used the electrolysis with the carbonate of soda, Arm & Hammer washing soda. (top shelf at Safeway) It worked surprisingly well but leaves everything kind of gray. I prefer a piece of stainless over the iron as the sacrificial anode. Now molasses...I'll have to give that a try.

Me again,
I don't know about any of you but I have had bad luck with WD-40 & the like for a rust preventative. According to the machinists at our local college, WD means water displacing & they recommend way-oil. I use 3-in-one, seems to work. In this coastal climate, if you want to see something rust, just put WD-40 on it! The solvent it contains takes the oil out of metal I am told. For what it's worth...

I got a terrible Lyman 4cav off of Ebay. It was rusted badly and pitted in the cavities. The seller offered a price reduction If I kept it. I stoned the many dings off of the flats. I used a NO. 2 pencil and scrubbed the inside of the cavities to clean them out. It casts pretty good now, but the bullets drop at .456" 452460. Maybe I should beagle it and have some light boolits for the 45-70?

Find naval jelly here: http://doitbest.com/shop/find2.asp
If that doesn't work just type in www.doitbest.com
and use their search for product. Basicall it's Do It Best hardware stores which should be just about nationwide.

Joe