PDA

View Full Version : Fixing up a gushow mold



doc25
01-26-2007, 06:50 PM
:shock: Here is what I did to fix up my rusty gushow mold. I picked up a Lyman 358477 single cavity at the gushow for $10.00 as well as a 358480 another $10.00 and a set of handles for $15.00 (this should teach the wife not to let me go out alone), this is my first trip into steel block territory as the only other molds I have are Lee.

The 358477 was rusty and I have read about cleaning molds with a battery charger so decided I would give this a try. All I had kicking around was a little power supply that was set up to charge alarm system type batteries so I went with this.

Next I had to find a sufficient container to hold the blocks, thank the Chinese takeout containers. Plastic and just the right size. Filled this with water to cover the blocks. I added an indiscrimitate amount of baking powder to the water and mixed it well. I needed an electrode to put on the positive side of the battery and found a drill bit to use (this will get partially eaten during the process so don't use your best ones.

http://usera.imagecave.com/doc25/IMG_0458-copy.jpg

That's a pic of my little set up and the drill bit attached to the positive lead.

http://usera.imagecave.com/doc25/IMG_0460-copy.jpg

Here is a pic of the power supply.

The alligator clip got attached to the sprue plate of the mold. It cleans the side facing the drill bit better. I left it in the solution for about 3 hours. Longer might have been better but I'm a bit impatient. I pulled it out a few times to brush the rust out of the cavity during the process.

Couldn't wait to test it. Well the sprue plate was also bent a bit so I had to fix this next. I figured I could just put it on a stone and we'd be O.K., I figured wrong. I had to start with sandpaper on a piece of glass. I started with 100 grit went to 220 then on with the water stones. Now I had the mold in good shape and was getting good boolits out of it ... except they wouldn't drop well out of the mold. I had to hit it so many times I knocked the wood off the handles and the whole mold ended up in my water quench :shock: this is the second time I've done this and it still makes my shorts wet and brown!

So now I had to make this thing drop a boolit. I cast a good one and drilled a hole in the base. Inserted a screw and took some of the sludge out of my water stone container. I put the sludge on the boolit that was chucked in the 18v drill and spun that puppy for about a minute or two. I kept stopping and putting more sludge on it to keep it lubricated and honing.

So how did it turn out? Just fine. The boolits seem to be dropping when I open her up or with just a little tap. Here is a pic of the finished mold.

http://usera.imagecave.com/doc25/IMG_0461-copy.jpg

Hope you enjoyed my little adventure.

Bent Ramrod
01-26-2007, 09:00 PM
doc25,

Nice save on your mould and congratulations on the gunshow bargains. I've never heard of that technique before.

I presume your charger is for small rechargable 9V batteries rather than automotive storage types. Did you set it to a given voltage? Did you see any potential pitting disappear and the rust go back to metal?

imashooter2
01-26-2007, 09:37 PM
Very good post! I've done the electrolytic rust removal on a few pieces... It really does a nice job and unless you hook up the current backwards, you can't damage the piece more than it already is.

If I might give a few tips based on my experience... 12 volts at 10 amps is a pretty good power source. A motorcycle or trickle charger will work, but a 12 volt 10 amp will work much, much faster. More might be better, but there comes a point where you start to boil off the electrolyte. If you are going to leave it overnight, make sure you use a container with enough capacity that the electrolyte doesn't boil down and expose the part you're trying to clean. Also, cleaning is pretty much line of site from the anode to the cathode. Setting up an old cookie tin as the anode and hanging the mold in the center of it works really well. I remove the sprue plate and hang the mold from a piece of bailing wire held under the screw. A good connection is essential to best cleaning. Negative lead to the part being cleaned! Hook it up backwards and you sacrifice the mold to clean the cookie tin. Last tip is that baking soda in water will make a solution that works, but washing soda is better.

Treeman
01-26-2007, 11:04 PM
That is nifty. Congratulations on your "new" moulds. FWIW, while noone would want to pit the cavities of the mould and letting tools rust deliberately is beyond me I have fouund that rusty moulds that I bought already 'damaged" actually release better than pristine ones and the micro-textured bullet surface loves to hold LLAlox.

doc25
01-26-2007, 11:11 PM
doc25,

Nice save on your mould and congratulations on the gunshow bargains. I've never heard of that technique before.

I presume your charger is for small rechargable 9V batteries rather than automotive storage types. Did you set it to a given voltage? Did you see any potential pitting disappear and the rust go back to metal?

The charger is for 12v batteries. This is small potatoes as far as the charger goes. I was just taking advantage of something I had lying around the house. I sure did not get the boiling type action I had seen at other web sites. The power supply has an adjustable voltage output but I used the battery charging side of it. I don't think the rust goes back to metal more like the rust seems to come off. As far as the baking soda goes it's what I had at home.

imashooter2
01-27-2007, 12:14 AM
The charger is for 12v batteries. This is small potatoes as far as the charger goes. I was just taking advantage of something I had lying around the house. I sure did not get the boiling type action I had seen at other web sites. The power supply has an adjustable voltage output but I used the battery charging side of it. I don't think the rust goes back to metal more like the rust seems to come off. As far as the baking soda goes it's what I had at home.

The first one I did was with baking soda too, and for the same reason.:)

monadnock#5
01-27-2007, 12:41 AM
Thank you for the post. Now I need to find a cheap fixer upper that I can experiment on!

handyrandyrc
01-27-2007, 01:48 AM
I have used Evaporust, with GREAT success:

www.theruststore.com

I went from THIS:

http://www.commbloc.net/handyrandyrc/images/oldreceiver1.jpg

To THIS -- literally OVERNIGHT:

http://www.commbloc.net/handyrandyrc/images/newreceiver2.jpg

pahoghunter
01-29-2007, 12:44 PM
I use a product call BLUE WONDER, which I think works great, but this product looks unbelievable.

Ricochet
01-29-2007, 05:14 PM
Baking soda and baking powder are two very different things, as my wife learned soon after we were married. I poured vinegar on something she'd made for a week so I could eat it. We couldn't afford to throw it out.

Washing soda's gotten hard to find. I've used baking soda and it works fine. It starts up working more slowly, but after it's bubbled for a while it ends up being basically the same stuff and does a great job.

TSP will also work as an electrolyte.

Be sure and wear gloves, protective clothing and eyewear when working with these alkaline solutions. Baking soda won't burn your skin, but washing soda and TSP will.

Billvz
01-30-2007, 03:34 PM
How did you place the mold in the solution? Together like when you cast, or just set them in any way you can ? were they touching or not

doc25
01-30-2007, 06:48 PM
I left them together wrapped in an elastic. Left the sprue plate on and attached the ground to the sprue plate. I moved them around a little and ended up with the cavity facing the drill bit. I was cleaning a lee shellholder the other night and used a larger piece of metal as an annode and it worked better. So as imashooter2 pointed out bigger power supply will also be better. I have a CB powersuply kicking around here and might give that a try. I'm just a NOOB at this and am trying things that I've read here and put them together into a post.

imashooter2
01-30-2007, 10:17 PM
Here's how I set mine up. Actual had a larger charger, better connections at the mold halves and an anode that completely encircled the mold halves to maximize exposure.

http://mywebpages.comcast.net/imashooter2/pictures/ERR-out.jpg
http://mywebpages.comcast.net/imashooter2/pictures/ERR-in.jpg

doc25
02-01-2007, 06:08 PM
I wonder if you couldn't just connect the + to a tin can and suppoer the mold kinda like you did and get an all around cleaning action?

imashooter2
02-01-2007, 07:08 PM
That's what I did in actual practice. The pics above were just tossed together to show an example of how I hang the mold halves. Punch a couple of nail holes in the bottom of the can so it sinks and add a strap lead to the top of the bucket to get the clamps out of the alkaline mist coming off the electrolyte.

Don't try to use the can as a vessel for the electrolyte and attach the lead to it. You'll have a hell of a mess on your hands when you dissolve a hole through it.

kywoodwrkr
02-01-2007, 09:43 PM
The ingredient I am going to use after finally finding it is PH Plus which is used for swimming pool conditioning.
It is 100% sodium carbonate or wash soda.
google electrolysis rust removal and complete instructions are available.
http://antique-engines.com/electrol.asp
fairly good explanation.
FWIW.
DaveP