How to use Cerrosafe

[corvette8n]

I got about 1/2 pound of Cerrosafe but got no directions with this stuff, I want to make a chamber cast, do I need to lube the bore. Whats the best way to plug the bore?, any tips appreciated.

[scrapcan]

http://www.brownells.com/aspx/NS/Gun...ons.aspx?p=384

You can download the instructions for cerrosafe at Brownell's. Maybe the above link will work. You will need to put cerrosafe in the search box and it should come up. the instruction sheet is in the shop work section. If you can't find it send me a pm.

Here is a thread started by PIWO that has alot of good info in it.

http://castboolits.gunloads.com/showthread.php?t=12989

[Nobade]

I just plug the bore with a patch and jag. That way I can put the rod back in after casting, screw it on, and push the casting out. I use a loaded round of ammo to stop the patch so I get an impression of the throat and first part of the rifling. I melt it in a RCBS ladle with the acetelyne torch, and pour. Don't lube the barrel, just make sure it's fairly clean. Be careful to keep the cerrosafe in the chamber and not in the barrel threads or it's hard to get out, especially on Winchesters and others that have an extractor cut.

[uscra112]

Gee, you shouldn't need that much heat to melt Cerrosafe.

And yes, the chamber should be SLIGHTLY oily. Very thin oil, and wipe out as much as you can with paper toweling or patches.

[Ranch Dog]

I'm glad I looked at MidwayUSA before I wrote as on March 7, I bought the 1/2# bars of CerroSafe for $7.99 each as it was on sale. I notice it is now $17.99 each

I had looked at USCRA's suggestion of McMaster-Carr as a source but didn't quite understand the price... is it $26.28 for one 1/2# bar (the bars are 1/2# each) or $26.28 for a pound and a half (3 1/2# bars)? I was going to call them but looked at MidwayUSA before the call and saw that they had it on sale. I have posted a screen-shot of the McMaster page with the info on the CerroSafe.

The instructions and technical data are available from the MidwayUSA web site:
MidwayUSA's Cerro-Safe Technical Specification

All I pretty much work with are the Marlins so the chamber casting is easy with the rifle broken down. You could do it with the bolt removed, but I use this as an opportunity to give the rifle a complete cleaning. The CerroSafe will manage to find it's way into some pretty tight places so I've found it easier to have just the rifle frame ready for the job. Clean the chamber, lightly oil it (then wipe it out with a patch), plug the barrel (I want about an inch of rifling with the cast), and cast it.

Cerrosafe's melting point is below the boiling point of water so I use a plastic funnel with a short length of vinyl tubing to get it to the chamber. The tubing is just long enough to reach the chamber with the funnel set through the back of the receiver. I heat the CerroSafe in a skillet ashtray, you will find these at Wal-Mart and they are quite handy at the casting bench, over a Coleman stove. At one-hour, I push the casting out of the receiver with a wooden dowel.

[uscra112]

The McMaster price is $26.28 for one ingot 1.5 lbs weight. But your deal with Midway beat that! That said, the "normal" price from Midway makes M-M look pretty good.

BTW one excellent use for all those low-melting-point alloys is to fixture odd-shaped parts for filing or machining. Especially good for small and delicate bits.

[georgeld]

I've got a question about this stuff. I've never used it yet and don't have any.

Once you make a cast with it. will it keep forever in that shape and size. or will it
shrink/swell after a few hours?

I've read brownell's post about it shrinking in awhile so it'll come out easy, then in a few minutes it swells back to proper size. But, nothing I've found tells whether it stays that way forever or not.

I know most guys reuse it over and over and wonder if that's the reason they do.

Thanks much,

[montana_charlie]

There is a point where the casting is the correct size. I think that is an hour after the cast is made. From then on it continues to expand until it reaches it's maximum size, which is a known percentage over 'actual' size.

Bullet mold makers, and others who get casts from their customers, know how to calculate the right number as long as the customer tells them how old the casting is.

If it's never overheated (and perhaps even if it is) the alloy can be reused indefinitely.
CM

[montana_charlie]

When it comes to calculating the measurement you are trying to determine, Cerrosafe's habit of changing size makes it appear to be useless. Here is a thread which explains how to do the calculations to come up with usable data.
http://groups.msn.com/bpcr/general.m...1&all_topics=1

CM

[35remington]

Proper procedure is to remove the Cerrosafe very soon after it has set up. It swells back to supposedly exact size one hour after it has solidified.

So, for best ease of removal take out the casting ASAP. It will be near minimum size at that time.

The more time passes, approaching that hour, the larger it will grow toward exact size, which may complicate removal.

You will find if a cloth patch is used for a plug that any loose fibers will get pretty well stuck to the Cerrosafe, so tidy up the frayed ends.

[Andy_P]

A couple of tips learned the hard way:

- before you start, make sure there are no obstructions to removing the casting, such as the extractor on a Rolling Block

- if there is significant pitting in the bore, that can make the casting very difficult to remove.