Resurrecting Dead Molds

[sutherpride59]

So just like it says in the title I have some molds that need to be brought back from the dead. My father-in-law recently passed away and left all of his casting equipment to me as he is the one who originally got me into bullet casting. Well unfortunately either some of the folks packing up his house or he himself somehow got these molds wet and they were stored wet for a few months till I PCSed recently and finally picked them up. Well the question is what's the best way to get the rust off these things without doing more harm than good. Admittedly a lot of the rust is just surface rust and is only on the outside of the blocks with very little rust on the inside of the molds. At least most of them anyway. There are about 40 of them total so I don't really think a light sanding by hand is going to be the most practical way of going about this. Is there something that I should soak them in? I remeber my grandfather once used a bath of lye mixed into water with a car battery charger on both ends to get rust off of railroad ties but I'm scared that might hurt more than help. Penetrating oil is just going to make the rust oily and the same with gun oil... The best idea I have come up with so far is to hit them up with a very thin bristled wire wheel, maybe a brass or bronze one. Any ideas? Thanks in advance.

[toallmy]

No wire brushes !!!!!!!!

[Yodogsandman]

Don't use any wire wheel!

[toallmy]

Sorry about the panic post above . I'm sure you will get a lot of good advice on chemicals and oils that will take care of the rust , and storage for after cleaning . I have recently saw molds for sale on eBay that have been wire brushed , what a shame .

[Iron Whittler]

HI. I AM CLEANING UP MOLD BLOCKS now that got wet from a/c condensate drain plug up. I got me a 3.5 gal. pail of EVAPORUST rust from the local O'Riely auto parts store. Comes with basket inside. Clean molds to remove oil, grease with soap and water using a Nylon or Brass bristle brush. I used compressed air to dry afterwards. Put molds in basket and soak 1 or 2 days. Remove from dip and wash with water, dry with comp. air. Use nylon or brass brush on cavities and mating faces to clean up. Worked GREAT on my vintage H&G, Magma, Lyman/Ideal mold blocks. Note-- I generously coated all blocks waiting their turn to be cleaned with Kriol oil to stop the rusting process until I could clean them. I have had 100% success at saving them so far. Still have many to go. DO not use power wire brush! Be patience, work gently around cavities and mating faces. You should be able to save them. :cbpour::Fire:

[Dusty Bannister]

There are many threads on this topic and perhaps you can review which one best suits your needs.

http://castboolits.gunloads.com/google.php?cx=partner-pub-6216953551359885%3A1942134700&cof=FORID%3A9&ie=ISO-8859-1&q=remove+rust+from+molds&sa.x=0&sa.y=0

[sutherpride59]

I feel dumb I clearly didn't search hard enough, evaporust from autozone looks like what will get the job done right. Everyone agree with that?

[Boolit_Head]

Evaporust is some good stuff, somehow converts rust to carbon somehow. I never looked into the chemistry behind it but it does leave a black residue. I found a pair of channel locks in the back yard I had been looking for 6 months. Thick frosty type of rust all over it. A few hours in Evaporust and a quick brushing and you could never tell.

[country gent]

Evapor rust should do a good job. The nylon bristle brushes are also a big help. Tooth brushes work but the ones sold in gun shops are a little stiffer bristle. A few wood sticks can be handy for rubbing stubborn spots also. Popcycle sticks and bamboo skewers from the supermarket work good and are cheap. A little coarse wool or burlap also is handy for working stubborn spots over. I would clean with dish soap and water with a nylon bristle brush really work up a lather of soap rinse and dry well. hebn a soak in the evaporust and light brushing wiping with a nylon brush. Any stubborn areas can be worked on with a popcycle stick with a squared end lightly. Pay attention to corners and edges. Magnification helps here to see what you actually have. Dont forget to clean the vent lines and qtips for pin holes and such. A good cleaning again with soap and water maybe a light boiling in soap water even rinse and dry well quickly then oil or wax to perseve. Take your time and work slow. A piece of coarse wool material or burlap glued to a popcycle stick makes a good "scrubber" that does no damage

[Traffer]

Check those ingredients.
Most of that stuff uses phosphoric acid. I would not use it on the mating surface or the mold surface. On the outside yes.
https://www.whatsinproducts.com/files/brands_pdf/10510_13010035%20MSDS%20Loctite%20Naval%20Jelly%20 Rust%20Dissolver.pdf

[gwpercle]

Try the Evaporust....I had never heard of it , I spotted some in Home Depot so it is readily available .
For a quick method to halt rust , until you can treat with Evaporust , submerge moulds in Kerosene ...they will not rust any further. Kerosene should be available at Home Depot...I know Wally Mart has it.
Good luck with the resurrections ....Gary

[Leadmelter]

Best stuff is evaporust. Non toxic, cleans in 24 hrs for heavy rusted pieces. Easy to find!
Leadmelter

[Bama]

Have not tried it with molds but works wonders on intricate precision machining parts is "electrolytic rust removal" it will only remove rust and nothing else. Look it up on net for detailed directions or if you can not find PM me and I will get a PDF for you. I have used it on the fine threads on micrometer that were rusted solid that had sentimental value. They work fine now. It will not remove pits but will remove all rust without damaging any solid metal.

[Echo]

HI. I AM CLEANING UP MOLD BLOCKS now that got wet from a/c condensate drain plug up. I got me a 3.5 gal. pail of EVAPORUST rust from the local O'Riely auto parts store. Comes with basket inside. Clean molds to remove oil, grease with soap and water using a Nylon or Brass bristle brush. I used compressed air to dry afterwards. Put molds in basket and soak 1 or 2 days. Remove from dip and wash with water, dry with comp. air. Use nylon or brass brush on cavities and mating faces to clean up. Worked GREAT on my vintage H&G, Magma, Lyman/Ideal mold blocks. Note-- I generously coated all blocks waiting their turn to be cleaned with Kriol oil to stop the rusting process until I could clean them. I have had 100% success at saving them so far. Still have many to go. DO not use power wire brush! Be patience, work gently around cavities and mating faces. You should be able to save them. :cbpour::Fire:

A Big Plus One for this. Evap-O-Rust is you friend. I keep a Mason jar 3/4 full for taking care of 2-cavity molds that have been neglected.

[rintinglen]

I used evoporust several times on heavily rusted molds and have had nothing but success. It strips the rust off and does not damage the iron or steel underneath.

I have a 311-291 that I was given that looked like a basket case but an overnight soaking followed by a good washing and drying with a hair dryer and it makes great boolits.

[kungfustyle]

Best thing is http://www.homedepot.com/p/Workshop-Hero-1-gal-Metal-Rescue-Rust-Remover-Bath-WH290487/203247483 Metal Rescue. I did a bunch of molds from a fiends workshop that were rusted and saved most of them. All you have to do is let them soak then wash them off with cold water and brush with a tooth brush under running cold water. You will need to immediately heat them up and hit them with rim oil but it works! Hands down for me it was the best thing.

[imashooter2]

Evaporust is probably easiest, but electrolytic rust removal is as good as it gets. A quick and easy set up I have used several times:

http://www.imashooter2.com/pictures/ERR-out.jpg

http://www.imashooter2.com/pictures/ERR-in.jpg

The trickle charger shown works over 24 - 48 hours on heavily rusted items, faster on light rust. A 10 amp charger does the same heavily rusted stuff overnight. The higher the amperage on the charger the faster it works, but the wires will need to be larger and the solution boils off so needs to be watched. Use a big enough container.

Washing soda in water is the preferred solution, but baking soda works in a pinch. A couple tablespoons to the gallon is good.

[Oklahoma Rebel]

maybe find a media blaster for the tougher ones and use or have them use the lightest and most gentle medium

[zuke]

I wet tumbled this mold, each half separate for 8 hour's

http://i807.photobucket.com/albums/yy356/zuke_bucket/DSCF2697_zps11f9a29d.jpg

http://i807.photobucket.com/albums/yy356/zuke_bucket/DSCF2696_zps3a3e643e.jpg

[hlvabeach]

White vinegar will also take care of the rust. Soak for a day or so I use it to clean rust off of cast iron frying pans. Thats probably the active ingredient for vaper rust.

[rwadley]

White vinegar.. probably the active ingredient for vaper rust.

Nope. Evaporust works by chelation.

It is a proprietary formula but many people believe the main ingredient to be the chemical "ethylenediaminetetraacetate or EDTA ".

EDTA:Ethylenediaminetetraacetic acid (or ethylenediaminetetraacetate). A synthetic amino acid (http://www.dekalbcounty.org/LEPC/cerpappendices.html#amino) (or acid salt) that acts as a chelating agent (http://www.dekalbcounty.org/LEPC/cerpappendices.html#chelate) for many divalent metal ions, particularly lead (Pb+2). A diagram of the acid's molecular structure is shown to the right. EDTA is used medically as an antidote (http://www.dekalbcounty.org/LEPC/cerpappendices.html#antidote) for lead or other heavy metal poisoning in the form of the di-sodium salt, chelated with calcium: Na2Ca–EDTA

http://www.dekalbcounty.org/LEPC/cerpappendices.html#E

[MT Gianni]

Go over them all with a #2 pencil and then use the eraser. No chemicals, just old fashioned elbow grease.

[sutherpride59]

Well just to follow up because I forgot to post my results the evaporust works miracles. A couple days of soaking cleaned these molds right up the only problem I can see is if there is major pitting after the clean up the mold seems to be pretty much *****. The only thing I can figure could have saved a few of these would have been cleaning them up on the faces with a green pad then casting with them some then running a cast boolit with some polish on it through the cavity with a drill bit like you would when leementing. At least then the pits might have been left with some of the rust in them to fill the holes. Any solution for these badly pitted molds.

[John Boy]

A50:50 mix of acetone & ATF. Let soak for about an hour and rub down with bronze wool ...

Recently “Machinist Workshop Magazine” did a test on penetrating oils. Using nuts and
bolts that they ‘scientifically rusted’ to a uniform degree by soaking in salt water, they then
tested the break-out torque required to loosen the nuts. They treated the nuts with a variety
of penetrants and measured the torque required to loosen them.
This is what they came up with:
Nothing: 516 lbs
WD-40 (http://www.westmarine.com/buy/wd-40--rust-remover-soak-gallon--13993761): 238 lbs;
PB Blaster (http://www.amazon.com/dp/B00U6VXKG4): 214 lbs;
Liquid Wrench (http://rd.bizrate.com/rd?t=http%3A%2F%2Fwww.amazon.com%2Fdp%2FB00TUGGCIO %2Fref%3Dasc_df_B00TUGGCIO4716792%3Fsmid%3DAVVEUTL ERXLGB%26tag%3Dshopz0d-20%26ascsubtag%3Dshopzilla_mp_1580-20%3BSZ_REDIRECT_ID%26linkCode%3Ddf0%26creative%3D 395105%26creativeASIN%3DB00TUGGCIO&mid=184059&cat_id=100001773&atom=100001774&prod_id=&oid=7093347481&***=1&b_id=18&bid_type=4&bamt=be85fa8f6ad737f6&cobrand=1&ppr=bdf5e89b47f7bb08&rf=af1&af_assettype_id=12&af_creative_id=2973&af_id=615103&af_placement_id=1&dv=a0cdb7222e8347b433fed2b4784e4dde): 127 lbs,
Kano Kroil (https://www.amazon.com/Kano-Sili-Kroil-Aerosol-Penetrating/dp/B0036RNKCO): 106 lbs
(ATF)/Acetone mix (50/50): 50 lbs.

[runfiverun]

mold prep.
you can build it up in the rust pits.
then lap the prep out with a boolit and the drill.
I prefer to run a star head screw into the base of the lap and turn it with a drill.
a couple of coats will fill the pits in.

[sutherpride59]

what kind of mold pre would you try?

[runfiverun]

the spray in graphite stuff.
they call it mold release too.
you might have good luck shooting a little in the lid then painting/dabbing it in, in thin coats, building it up slowly, then a final light sprayed in top coat you can lap smooth.
you might not get perfect but you should be able to get them back to useable.