I put a mold in the vibrator over night

[Johnch]

I bought 4 molds a while back at a auction
All but 1 just needed a little TLC to be usable again

But a Lyman 429421 was another story

Who ever had allowed this mold to rust on the outside
And the inside was rusty and the cavitys were coated with some type dryed grease ( not sure if it is grease )

I got the worst of the dryed crud out
Tryed Shooter's Choice , Brake cleaner , Ed's Red and straight PVC cleaner
Even used a brass brush

But none of them would get the last of the crud out
I even tryed casting a few to see if heating the mold would lossen the crud

So I figured , I am out nothing , as 1 of the 3 usable molds was worth more than I had given for all 4

So..... I put each 1/2 in a seperate vibrator with used corn cob media and set the timer for 6 hours
I used 2 vibrators to insure one 1/2 would not damage the other 1/2 any farther

What ever was in the cavitys apears to be gone and while not perfictly looking
The worst of the rust is gone

So I cleaned the mold off with PVC cleaner and started a pot of WW/Range lead heating

I will see if the crud is truely gone and if this abused mold is now usable
Or I finished it off [smilie=1:

John

[Trey45]

I'm interested to see what the outcome of this experiment is as well, keep us posted!

[wallenba]

I've used this stuff on motorcycle parts and it works GREAT! http://www.safestrustremover.com/
It's a bit pricey but it keeps, it's non-toxic and can be disposed of down the drain.

[beanflip]

keep us posted on the out come of this John.

[Johnch]

Well I just got done casting a few , wish I had a camera
As Pic's would show more than I can explain

What ever was in the cavitys is gone
After perheating the mold on a hot plate , the first 8 - 10 trys were rejected and then both the cavitys filled out
Without any signs of what ever was in the mold


1 cavity is pitted and the boolit needs a little help droping

The other cavity drops OK

OK as for the look of the cavitys
Both cavitys are now out of round .431 , 90 degree they measure .433 - .4335
As I never saw the mold before it got rusty
I have no clue if the mold droped a round boolit before

The cavitys look like they were lightly sand blasted , probely from the rust

All the sharp edges are slightly rounded
The top edge of the drive band on both cavitys now has a radius , not a sharp cornner

Also on the drive band of the boolit , you can see the roughness
Especaily on 1 cavity

Did the old corn cob medai harm the mold ?
Maybe a little ,I am sure it didn't do the mold a lot of good
I bet if the medai was new , more damaged edges would had been shown

A Alumiun mold would probley shown a lot more wear
So IMO not a good idea for a Al mold

Is the mold usable , yes
Are the boolits pretty .....no
But I will size a few and I bet they shoot fine

John

[John Boy]

What ever was in the cavitys apears to be gone and while not perfictly looking. The worst of the rust is gone
Scrub the molds with a 50:50 solution of ATF:Acetone. Not a believer?

Machinist's Workshop Mag (tm)recently published some information on various penetrating oils that I found very interesting. Some of you might appreciate this. the magazine reports they tested penetrants for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional
machinist.
They arranged a subjective test of all the popular penetrants
with the control being the torque required to remove the nut from
a "scientifically rusted" environment.
*Penetrating oil ..... Average load*
None ...................... 516 pounds
WD-40 ..................... 238 pounds
PB Blaster ................ 214 pounds
Liquid Wrench ............. 127 pounds
Kano Kroil ................ 106 pounds
ATF-Acetone mix..............53 pounds
The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone. Note the "home brew" was better
than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use
it with equally good results.
Note also that "Liquid Wrench" is about as good as "Kroil" for
about 20% of the price.

[Skipper488]

A Alumiun mold would probley shown a lot more wear
So IMO not a good idea for a Al mold

John

All right I got to say it. Not a big rust problem with Aluminum molds.:kidding:

[jixxerbill]

Scrub the molds with a 50:50 solution of ATF:Acetone. Not a believer?

Machinist's Workshop Mag (tm)recently published some information on various penetrating oils that I found very interesting. Some of you might appreciate this. the magazine reports they tested penetrants for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional
machinist.
They arranged a subjective test of all the popular penetrants
with the control being the torque required to remove the nut from
a "scientifically rusted" environment.
*Penetrating oil ..... Average load*
None ...................... 516 pounds
WD-40 ..................... 238 pounds
PB Blaster ................ 214 pounds
Liquid Wrench ............. 127 pounds
Kano Kroil ................ 106 pounds
ATF-Acetone mix..............53 pounds
The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone. Note the "home brew" was better
than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use
it with equally good results.
Note also that "Liquid Wrench" is about as good as "Kroil" for
about 20% of the price.

they should call it wd-41 ???

[nanuk]

I was told about that study just three days ago. I've been using Diesel and ATF/acetone for the last couple years


several years ago, a guy I worked with brought a book from the library that had OLD recipes for all kinds of stuff. I think Diesel and acetone was one of the penetrating oils listed.

[docone31]

You might try some lapping compound on castings with a nut on the sprue. That should clean up the little bits of pitting, and help make it a little more in round. I do not think out of round will really be an issue as the barrel swages the casting. With sizeing, then firing, it should do well.
The walnut, or corn media did not hurt the mold. If it had been stainless shot, and it vibrated for a couple of days, you would have seen a definate change. Shell media is not that agressive.
If you get another mold in that condition with the grease, try Easy Off!, or sodium hydroxide.
Get it wet, let it sit. Rinse.
It will burn the hands though.

[Johnch]

You might try some lapping compound on castings with a nut on the sprue. That should clean up the little bits of pitting, and help make it a little more in round. I do not think out of round will really be an issue as the barrel swages the casting. With sizeing, then firing, it should do well.
The walnut, or corn media did not hurt the mold. If it had been stainless shot, and it vibrated for a couple of days, you would have seen a definate change. Shell media is not that agressive.
If you get another mold in that condition with the grease, try Easy Off!, or sodium hydroxide.
Get it wet, let it sit. Rinse.
It will burn the hands though.

Thanks , Never thought about EZ Off


I sized 50 tonight at .431
And yes they are now nice and round
But I hope to never have to fix someones screw up again :cry:

It isn't the corn cob media itself I was worried about
It is the red rough or what ever it is
I know it is abrasive

John

[dromia]

Scrub the molds with a 50:50 solution of ATF:Acetone. Not a believer?

Machinist's Workshop Mag (tm)recently published some information on various penetrating oils that I found very interesting. Some of you might appreciate this. the magazine reports they tested penetrants for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional
machinist.
They arranged a subjective test of all the popular penetrants
with the control being the torque required to remove the nut from
a "scientifically rusted" environment.
*Penetrating oil ..... Average load*
None ...................... 516 pounds
WD-40 ..................... 238 pounds
PB Blaster ................ 214 pounds
Liquid Wrench ............. 127 pounds
Kano Kroil ................ 106 pounds
ATF-Acetone mix..............53 pounds
The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone. Note the "home brew" was better
than any commercial product in this one particular test.
Our local machinist group mixed up a batch and we all now use
it with equally good results.
Note also that "Liquid Wrench" is about as good as "Kroil" for
about 20% of the price.


Any one ever tried mixing ATF and Acetone?

[Bret4207]

Dromia, back when a gallon of acetone was only like $3.00 I tried it. It works good, but so does diesel/ATF, mineral spirits/ATF, gasoline/ATF. I think it's the detergents and lube in the ATF that does the work, the solvent is just there to thin it. Something that is kind of steep but would be worth trying is Lucas brand automatic transmission repair in a bottle. It's got some stuff in there that will make a sticking auto tranny unstick. If it's got more stuff to it than AFT it might work better than ATF.

[Bret4207]

Johnch, I have a couple of "beater" looking moulds that cast just fine. A few cycles of heating and cooling seem to help things "fix themselves". The tiny pits will make easy release a bit of a tough sell, but polishing the cavity will help that. Simply going over the interior of the mould with a Cratex bob (by hand) or typewriter eraser will make a big difference.

[dromia]

Thanks Bret, I've tried it too, but my problem was the acetone and the ATF wouldn't mix.

Any suggestions?

[Dan Cash]

Any one ever tried mixing ATF and Acetone?

Such a mix is part of the "Ed's Red" formula. ATF on its own is excellent as a penetrating oil. Those things which dilute the fluid seerve to enhance its ability to penetrate. Sadly, Acetone has become quite spendy.

[thehouseproduct]

Wouldn't Ed's Red probably work well?

[mike in co]

they should call it wd-41 ???

nope....wd is water dispersal.....try number 40.....

not a rust buster....


mike in co

[lavenatti]

Don't use the easy-off on aluminum molds. The strong alkaline cleaners like this one will react with the aluminum and ruin it fairly quickly. It'll clean the steel molds great though.

I used to use some aluminum foil and sodium hydroxide to make hydrogen gas to fill balloons. Lots of fun, especially since they can easily be turned into a ball of orange fire with the careful toss of a match.

[Bret4207]

Thanks Bret, I've tried it too, but my problem was the acetone and the ATF wouldn't mix.

Any suggestions?

Huh. It's been a while but I don;t recall any problems with that. Is it possible that European ATF is formulated differently than US stuff?

[HeavyMetal]

Must be 6 different formula's of "ATF" on the shelf at the local Wally World seems every car maker now has it's own "flavor"!

Back in the day you only had two choices: Dexron or ATF Type F for Ford's. These ATF's may mix more readily with Acetone but may be way harder to find in Europe.

I'll have to give this a try sometime and see how it works.

As far as acetone being "spendy"? Ya if you go to a chemical house and ask for a gallon!

For some odds and ends nut and bolt removal process go to SWMBO's dresser and swipe her finger nail polish remover which runs about a buck or two. This is acetone.

By the way don't get caught!

That should make all the penatrating oil you'll need.

[Shakey Jakey]

I have found nothing better than the electrochemical 5 gallon bucket and battery charger method.

[1Shirt]

A sonic cleaner works well!
1Shirt!:coffee:

[oscarflytyer]

I was told about that study just three days ago. I've been using Diesel and ATF/acetone for the last couple years


several years ago, a guy I worked with brought a book from the library that had OLD recipes for all kinds of stuff. I think Diesel and acetone was one of the penetrating oils listed.

Durn near Ed's Red! Kerosene vs Diesel and add some mineral spirits...

[home in oz]

Interesting fix.

[Plinkster]

I wonder if the 50/50 mix of ATF and acetone would work as a mold release the way that Kroil does? Anyone brave enough to try it? I might have to if I can remember it next casting session.