Help......rust in my molds

[ihmsakiwi]

Help please. Mid-summer the humidy is ' Florida-like" and I have found a couple of my molds are throwing rough boolits. On closer inspection I think I have very fine rust. Tried cleaning with cotton bud and Turpentine to see if I could clean them up but to no avail. What is the best repair method. I store them all wrapped in oil soaked cloth but somehow the humidy must have affected them.
Peter.

[Frank46]

Couple suggestions, try using a bore brush attached to a drill with hoppes run at low speed. Another would be to try using a mild abrasive such as jb bore paste or rem clean in conjunction with the bore brush. If all else fails then more drastic measures are called for. Take a couple of the bullets from the rusty molds and drill and tap for a 1/4x20 bolt, then use some fine lapping compound on the bullet, insert in mold and rotate bolt with drill at low speed. Check frequently to see how the rust removal is progressing. Here you want to remove the rust not metal. Or try naval jelly as it will remove the rust. But oil the mold and its cavities after cleaning out the naval jelly. The metal will look grey in color. You may want to heat up the mold till it turns blue from the heat, this oxidation can be acheived by simply casting some bullets. Serves two purposes, one is to check for any remaining rust, more cleaning may be indicated and the blue color or oxidation also helps to prevent rust. Hope this helps. Frank

[utk]

Visit this thread:

http://castboolits.gunloads.com/showthread.php?t=3463&highlight=electrolytic

I've used the electrolytic method (with baking powder as electrolyte) on two objects with good results - all rust gone.
The surface was pitted somewhat, as you can not "replace" the rusted steel.
One warning though, my objects started rusting immediately upon drying.

Another link:

http://www.graybeardoutdoors.com/phpbb2/viewtopic.php?t=58930&highlight=electrolytic

Urban

[Buckshot]

..................Here in So. California humidity isn't a real big issue and I've not had any issue at all with rusting until recently. HOWEVER! :-), I was removing moulds in preperation for some re-organizing (putting things in new places where I won't remember) and I found a couple Saeco moulds in their cardboard boxs with RUST on the top of the blocks and sprueplate! EEK!!

I immediately began checking the Lyman and RCBS blocks in thier plastic boxs. No problems. These also have the original VPI chips and a few I'd added over time. I don't know which to credit? The chips or the boxs. Regardless, I ordered up a supply of VPI chips and those blue plastic boxs Midway sells. The Saeco's are too big for Lyman or RCBS boxs and rattle around in the blue Midway deals but they're better (IMO) then the cardboard ones they came in.

So now I will try to live up to my idea of years ago, and that was to buy a bag of VPI chips yearly and place one in each mould and die box.

If I lived in a more active humid climate I'd take more drastic measures, such as oiling. I hate the thought of boiling, scrubbing, or flushing oily blocks before I can use them, but if that was the best way, it's cheaper then new mould blocks for sure.

................Buckshot

[joeb33050]

Help please. Mid-summer the humidy is ' Florida-like" and I have found a couple of my molds are throwing rough boolits. On closer inspection I think I have very fine rust. Tried cleaning with cotton bud and Turpentine to see if I could clean them up but to no avail. What is the best repair method. I store them all wrapped in oil soaked cloth but somehow the humidy must have affected them.
Peter.

Naval jelly, or phosphopric acid. Eats the rust away, doesn't bother the steel. Cheap and easy. Must-have in FL.
joe b.

[XBT]

…..and when you get them clean, oil the hell out of them. A couple of minutes with a toothbrush and some common rubbing alcohol before use and you’re ready to cast again.

I have used this method for many years with no problems. The old advice about never oiling a mold is wrong, they come from the manufacturer oiled don't they?

[floodgate]

Buckshot (and others):

"Here in So. California humidity isn't a real big issue and I've not had any issue at all with rusting until recently. HOWEVER! , I was removing moulds in preperation for some re-organizing (putting things in new places where I won't remember) and I found a couple Saeco moulds in their cardboard boxs with RUST on the top of the blocks and sprueplate! EEK!!"

Yeah, ordinary cardboard will suck up any moisture in the air, I had a bunch of moulds stored in little commercial slip-top boxes I got somewhere, and within a year, many of them had developed light rust film - even in the Northern Mojave Desert! The old Lyman / Ideal boxes were OK; they seem to have had some sort of wax or ??? treatment.

The blue Middleway boxes work for my "excess" moulds, but I have to clip off the little "fin" under the lids of the smallest ones I use for SC mould blocks.

Doug

[RayinNH]

I keep my moulds in an ammo can with the little dessicant packs that come packaged with electronics and shoes. I've never had a problem with them stored in this manner...Ray

[ihmsakiwi]

Thanks guys. Gave the molds the drill treatment with a copper brush and a little steel wool for good measure. Seems to have removed the worst of it. only the Lyman molds have been affected, the SAECO ones are fine, and of course the Lee ones.
I have found a new home for them in the house, and will find an airtight tin / container and get me some of those VPI thingies.

Great help guys.

Thanks, Peter.

ps. It was my favourite 35 Cal mould, the RCBS 200gr that was worst effected. I have to say it is now 8 years since I last shot a "bullet", and my IHMSA pistol scores are better than with condoms.
Just bought a Freedom 353, and was blown away by the accuracy of it with the RCBS. I shot 8 out of ten " half size " rams at 200 meters. I LOVE cast boolits.

[Buckshot]

.................I forgot to say welcome to the board, so welcome! Does the handle, Ihmsakiwi, denote a friend from NZ?

....................Buckshot

[waksupi]

ihmsakiwi - welcome aboard.
I'll add to Buckshots decription, In Her Majesty's Service? Active?

[Vegas Vince]

I used to live in Santa Cruz, humidity was always a problem. I bought some Tupperware type containers. They were the size of a shoe box & will store six to eight molds in each box. Then through in some moisture absorbing packets to put in each box. I never had a problem after that.

[ihmsakiwi]

Thanks guys. Yes I am an old shooters .com attendee and went through all the same withdrawl symtoms others went through at the time. Yes, I am in New Zealand, and an avid cast bullet IHMSA shooter and caster. Mid-summer and more humid than normal temperatures low 30's, humidy high nineties the last month or so.
I got ALL my knowledge from this and the old Shooters site and really felt part of the old "shooters" family.

Still to make up a batch of FWFL got most of the ingredients only the lack of a sodium sterate source is stopping me.

thanks for the welcome. Peter.

[tomf52]

To keep your molds from rusting, put them away while still warm, not hot as to damage the bags, but warm in zip lock bags. You should have no further trouble.

[bruce drake]

OO Steel wool and some gun oil usually takes the rust off of firearms without harming the bluing. This of course is for minor rust issues.

Bruce

[Beau Cassidy]

This ought to fix you up...

http://www3.telus.net/public/aschoepp/electrolyticrust.html

[fourarmed]

Where I live, the humidity problems are similar to yours. What I am trying, is vacuum sealing the blocks in my wife's Foodsaver. I do it as soon after casting as I think the mold is cool enough not to melt the vacuum bag, or I preheat the mold on the furnace grate or in the oven. I also wrap them in a dry paper towel so the corners of the mold don't puncture the bag. So far, it has worked, though I haven't been doing it long enough to be sure.

[anachronism]

One additional point. I used to use Breakfree to oil moulds, but do so no longer. I started having a lot of problems with poor mould fillout, and traced it to the penetrating qualities of the Breakfree. It seems it would penetrate the pores of the metal, and was the very dickens to remove! I had a few that I used Kroil on, and that was even worse. I only use the cheap stuff on moulds now.

[7s&8s]

For fear of rust, I've been using chain lube once cooled and storing in ammo can. Alcohol or other light solvent and toothbrush to clean up prior to casting.

[Blackwater]

This applies to rust that's hopefully WAY past what we'll ever find on a mould, but I recently cleaned up and redid a couple of guns for a friend, and to my surprise, the thing that worked best on the heavy rust was plain liquid hand soap and a nylon bristle brush, or on the hard stuff that wouldn't respond to the nylon, a brass brush. A friend who's familiar with cleaning chemicals said the liquid soap (NOT detergent, which is a whole 'nother set of chemistry) worked because of the oils in it. The lye (or whatever caustic) softens and breaks up the rust, while the oils emulsify, or soak up the broken down rust, making it easier to wash away with no harm to whatever steel is still remaining. It also appeared (to me at least) to penetrate down into the pores better than the traditional 0000 steel wool and oil that I've always normally used.

I'd apply the soap full strength, brush it about like I would my teeth, and it would just slowly disintegrate, and allow itself to be washed away in a hot tap water rinse. Surely worked good for these projects. Can anyone with greater knowledge of these chemistry matters explain why the soap did so well for this?

BTW, got it blued a couple of weeks ago, and it came out WAY better than I'd ever hoped. My gunsmith outdid himself on the receiver and barrel of the shotgun. The rifle's still awaiting bluing. Have to finish the stock before I finish the metal.

Rust is a common problem, or at least one we commonly fight, and the more I learn about how to deal with it, the less I find I really know about it. Ain't it funny how that works?