Rust on moulds?

[340six]

Since everyone so far says not to oil them on the inside where the lead gets to. What is best mantinance practice?
Oil and burn oil out with small propane?
Also when looking at new old stock moulds stay away from any rust 100% or is some ok like this pictore shows?

[RobS]

I would have to say a mold like the one you have pictured is..................."rough". Although you can maybe salvage the mold one would have to work hard at it and have to lap the mold with lapping compound of some sort (Leementing process). If you do not know what Leementing is, it is a sticky on this forum just search it. More than likely the bullets cast from a heavily rusted mold will have pits in the cavities as the rust even when removed will still show the flaws left over that is unelss you lap the hell out of it which will increase the bullets overall diameter.

Light rust can even give some problems. I personally would not buy any mold with heavy rust on it.........light rust questionable. If rust in on the outside of the block that is not a big deal, but on the inside it is just not something I will consider.

That being said, I always oil down my iron molds with Remington oil after use and then when I use them again I preheat them on a hotplate to warm up. When I come back after 20 minutes or so all the oil has burned off. If not then it is not too big of a deal to simply have a bottle of rubbing alcohol and some Q-tips around to clean out the oil prior to casting.

[fredj338]

I use Borwnell's mold release for the inside & Any rust prev. spray on the outside. I will often leave the last pour inplace if coming bacl to the mold sooner than later, no oil at all. I live a few miles inland from the coast in SoCal so humidity is not a huge problem.

[340six]

You guys have pretty much posted what my own thoughts were. I have a 30+ year back ground with metal sufaces on engine parts cranks cams ect would be even more unuseable "but" I am new to casting and thought maybe it is ok to some point.
I found it funny that the mould is bid so high on ebay if it was messed up.
As a new commer to casting I will only buy new or as new to limit my rate of failure

[dragonrider]

340six wrote "Since everyone so far says not to oil them on the inside where the lead gets to." This refers to when your molds are in use, they should be clean and free of oil. When not in use they should be protected with something, it will need to be cleaned off before next use.

[longbow]

Hard to tell from the photo but if the rust is light and powdery then it will "wipe" off fairly easily. The cavities may have to be lightly lapped but I doubt there is any significant damage or pitting.

If rust isn't scaly or if there isn't obvious pitting then the mould should be salvageable.

I always oil my iron moulds after use. I leave a couple of boolits in th emould after casting then open the mould and use a light gun oil, 3 in 1 or automatic transmission fluid to coat the inside and outside surfaces.

Some seem to have trouble casting after oiling moulds, I do not. I usually just wipe them off thoroughly with a rag or paper towel then cast. If they are really oily I use brake cleaner or Varsol to wipe them off.

I would rather wipe of oil than scrape and polish off rust.

You might do a search as many people have posted suggestions for cleaning up old/rusty moulds: scrape with pencil lead, rub with steel wool, scrape with brass or copper, naval jelly, lapping, and a host of others.

If you aren't going to buy the mould then not too important but sometime you may see an old mould you want that is out of production or just at good price (like free). Even rusty it may be salvageable with a bit of work.

Longbow

[Hickory]

I'd try using "Bar Keepers Friend" and a tooth brush to remove the rust.
It won't scratch or inbed into the metal.

I've used it when ever I get rust and have never had a problem with it.

[bearcove]

They don't look all that bad. I bet you could clean them up and cast fine boolits.

Put the halves together use a q-tip with kroil. Wipe the cavity with clean q-tip. Then cast a batch and see what you get.

Then you can lap the cavities if you need to.

What are they going to be used for, plinking? Load some up and try them.

[mooman76]

I was thinking also they don't look that bad to me. My bullets don't have to be perfect and that beinga pistol mould imperfections are not as critical as a rifle bullet mould where the bullet will be traveling a longer distance. The caveties don't look too bad barring a few bad spots and the cavities are what counts. Most of what I see just looks like surface rust but pictures can be mis leading. Go over it good with a lead pencil, a carpenters pencil works best. It will remove most if not all the surface rust and the lead won't hurt abit in fact some use it like a release agent. It you still have some bad spots you can probably get the rest with a good rust penitrator and a tooth brush or even some very fine sand paper on the flat areas of the mould. They say to avoid oil in the cavities but that's not for storage but that also depends on where you live. I don't oil mine but the humidity here is normally in the single digits to low double digits, like 12%. I would oil them if I din't plan on using them for a very long time though.

[shooter575]

At one time I did not oil my molds.I lost one and decided to oil after that.I use a spray type oil.Then spray with brake clean before using.
BTW that pistol mold dont look that bad. I have cleaned up worse looking ones

[340six]

I have been looking for that type mould and it is no longer made.
All I have seen in the last six months were singles in as new shape.
It is realy a full wad cutter with just a button rasied up in the center.
Guess I should say "almost" a full wad.

[shotman]

Kroil and a plactic bag dont need to clean them. Kroil {Kano labs} sells a stuff Exrust it will take that type of rust off in about 5 min. . Put Kroil on it and start casting

[Echo]

The mold looks like the H&G 130 that was well regarded by pistoleros. I believe Lyman made a clone, the 452374, but that mold looks like the 452389. In any case, I believe it is easily rehabbed. I don't see pitting - pitting would be a bad thing. Surface rust is easily removed.

[Bret4207]

If you can find one, a typewriter eraser works. They have an abrasive in the rubber, kind of like a Cratex polishing drum has and you sharpen them in a pencil sharpener to get in the little nooks.

I store my moulds empty and clean in a dead refrigerator with a 25 wat light bulb and a large Brownells desiccant box inside. No rust, no problems.

[badgeredd]

I thought about this last night and now want to ask if anyone has used electrolysis to clean up iron molds? It would seem that if the rust was heavy this would be the best way to clean them with minimal damage. Am I all wet?

Edd

[Tazman1602]

Since everyone so far says not to oil them on the inside where the lead gets to. What is best mantinance practice?
Oil and burn oil out with small propane?
Also when looking at new old stock moulds stay away from any rust 100% or is some ok like this pictore shows?

No way man. After EVERY use of my good steel molds they get SOAKED with WD40 and are KEPT that way until I use them again. Then before use I put them in a container of Laquer thinner and clean all the oil out of them and then let them DRY before you cast with them.

Laquer thinner ain't cheap anymore, dam near $20/gallon in my area so I have one quart I use specifically for this purpose and when the mold is clean I dump it BACK in the can because I ain't gonna use it for painting.............

Art

[JMtoolman]

I find it somewhat of a surprise that most of the casters oil there molds. I have been casting for about 55 years and do not oil my molds, and I have never had a mold rust at all! I store my molds, sometimes for years, in 50 cal ammo cans. I have some dessacant in the cans. I also use a "Neo-Lube" product on my molds for a mold release. It seems to provide a rust prevention coating. Other than that I don't do anything to my molds, just recoat with the Neo-Lube before casting. Thats it. The toolman.

[cast-n-blast]

All my molds get a dunk in Ed's Red, after use. When ready to use again, spray with carb., or brake cleaner, and you're ready to go.

[longbow]

Naval jelly (phosphoric acid) is one of the safest and easiest ways to remove rust without harming iron or steel parts like boolit moulds. If will remove the bluing though so don't slop it where you don't want it.

After use it will be obvious if there is pitting that requires lapping . Naval jelly is readily available at hardware stores. Do not use it on aluminum!

After removing rust with naval jelly the surface should be protected from oxidation, so in the case of a boolit mould ~ cold blue, heat bluing or oil. If oiled the bare surface will gradually heat blue with use. Same applies for lapping since the blue is removed.

Here is some info from Joe Brennan on rust removal:

http://www.lasc.us/Brennan_Remove_Rust.htm

And info speciffically about phosphoric acid (rust removal is about 1/2 way down the article):

http://en.wikipedia.org/wiki/Naval_jelly

Longbow

[340six]

The cavities may have to be lightly lapped whats that meen?