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JeffinNZ
04-27-2009, 12:40 AM
Team.

How dense is Cerrosafe? I want to get some in to do the chamber on all my rifles. If I order 1/2lb bar how many .303 Brit chamber casts would I likely get?

Lee
04-27-2009, 12:44 AM
I am not sure of the content of your question. 1/2 lb. should be a lifetime supply. It is re-useable. Do a chamber. Re-melt and do another chamber.

Or am I missing something in the post???


..................

malpaismike
04-27-2009, 12:47 AM
The short answer is, I don't know. I do know that I got 2 ingots from Brownell's for not much golddust, have cast ~40 chambers, and still have a virgin ingot. I think it would take a shotgun bore to use both ingots, but I don't own a .500 Gibbs, so who knows? The stuff is all but infinitely reusable. There may be loss to evap, but it's not evident yet, and I've used this batch for nearly 10 yr. BTW, it's easy as pie; I melt it in a tuna can--lip bent to a pour spout-- on top of a putty knife in my vise. A propane torch is overkill; it'll work with a bbq lighter, just more $. Hope this helps.

montana_charlie
04-27-2009, 11:06 AM
If I order 1/2lb bar how many .303 Brit chamber casts would I likely get?
I'm guessing somewhere between six and eight...if you plan to keep them forever. As said, the stuff can be melted down and used repeatedly.

Once you have cast a chamber and recorded the dimensions, there isn't much value in keeping the cast - because it's dimensions are going to increase over time.

CM

JeffinNZ
04-27-2009, 06:20 PM
I'm guessing somewhere between six and eight...if you plan to keep them forever. As said, the stuff can be melted down and used repeatedly.

Once you have cast a chamber and recorded the dimensions, there isn't much value in keeping the cast - because it's dimensions are going to increase over time.

CM

Gotcha! Thanks.

Interestingly enough Track of Wolf are SIGNIFICANTLY cheaper for Cerrosafe than Bronwells. USD16 compared to USD28.00 from memory for 1/2 lb.

geargnasher
04-27-2009, 09:17 PM
Rotometals sells a "chamber casting alloy", as I recall it was like $12 a pound (+shipping if that was all you bought). Just a thought.

Gear

blackthorn
04-28-2009, 11:27 AM
What follows is the information I have accumulated on using Cerosafe in chamber casting. I also include information on making chamber casts with a sulphur/graphite mix. This mix seems to have some advantages over Cerosafe as it does not change "as cast" dimensions over time. Hope you find this usefull.


CERROSAFE:

While the makers of Cerrosafe produce several different alloy combinations, the one we are concerned with consists of the following percentages: Bismuth - 42.50, Lead – 37.70, Tin – 11.30, Cadmium – 8.50. Note: Cadmium is very toxic so use good hygiene and avoid breathing the fumes. We all know the harmful effects of inhaling or digesting lead. Cadmium, is even worse. Its compounds are extremely toxic even in low concentrations, and will bioaccumulate in organisms and ecosystems. So use similar but even greater caution when working with Cerrosafe as you would when handling lead.

Notes:
 Melts between 158 and 190 degrees Fahrenheit
 Should be melted in a clean iron ladle without direct flame on the product.
 The chamber being cast should be cleaned thoroughly and a thin coat of oil or graphite applied.
 Reusable

Contraction - expansion factor versus time, after casting, measured in inches per square inch:
 2 minutes -.0004"
 6 minutes -.0007"
 30 minutes -.0009"
 1 hour +-.0000"
 2 hours +.0016"
 5 hours +.0018"
 7 hours +.0019"
 10 hours +.0019"
 24 hours +.0022"
 96 hours +.0025"
 200 hours +.0025"
 500 hours +.0025"

Basic Instructions:
 Plug the bore about one inch ahead of the throat of the firearm using an appropriate size cleaning patch.
 Pour the molten alloy directly into the chamber until full and allow it to cool, it will turn a shiny silver color. As soon as it has cooled enough that it is no longer a liquid (and doesn't present a burn hazard), run a rod into the bore from the muzzle and tap the casting out of the chamber. Take care not to overfill the chamber as the alloy will then run into the locking lug area, making removal extremely difficult. Any recessed areas can be plugged with modeling clay prior to pouring.
 During the first 30 minutes of cooling Cerrosafe shrinks and then begins to expand. At the end of one hour it should be "exactly" chamber size. The Cerrosafe will manage to find its way into some pretty tight places so it is easier to have the rifle stripped to the frame prior to commencing the job. Clean the chamber, lightly oil it (then wipe it out with a patch), plug the barrel at a point that allows the formation of about an inch of rifling to be included in the cast, and cast it.

Cerrosafe's melting point is below the boiling point of water so you can use a plastic funnel with a short length of vinyl tubing to get it into the chamber. The tubing should be just long enough to reach the chamber with the funnel set through the back of the receiver. Heat the Cerrosafe in a skillet ashtray, or other container with a pouring spout, over a heat source set on low. As soon as the cast has set up, push the “plug-patch” along with the casting out of the receiver with a wooden dowel.

When making a Cerrosafe cast of a high-wall rifle, the action must be disassembled and, depending on when the cast is measured, a mathematical adjustment (see above chart) may be necessary due to material expansion. Also, when using Cerrosafe to determine case OAL, headspace must be measured separately, which can be somewhat complicated.

One additional excellent use for all of the low-melting-point alloys is to “fixture” small, delicate and/or odd-shaped parts for filing or machining.

If you want to confirm the accuracy of the casting, to determine the expansion across the diameter of the casts, compare the cast to a soft lead slug, which has been driven into the throat and bore. To check length expansion, use the following technique.

The rifle is loaded with a case almost filled with lead, that has been previously fired in that firearm but left unsized and the action is closed. With the butt of the rifle resting on padded carpet and the muzzle pointing up, thick soft lead wire is dropped down the bore. Using a steel rod longer than the bore and slightly smaller than the bore diameter, pound/drive the wire into the unfilled mouth of the case and fully expand it into the chamber and throat by “pounding” on the end of the rod with a hammer. The resulting case and formed end provide a very accurate representation of the chamber, freebore, throat, land and grooves. Simple precautions such as spaced areas of tape placed around the rod will eliminate possible rod-damage to the chamber and bore.

Because a “slugged image” of this area made in this way does not shrink or expand over time, this method is cheaper, simpler, easier and more accurate than using Cerrosafe. In addition, a measurement from the rear of the rim to the start of the transition step includes the actual headspace of the rifle and provides the overall length (OAL) of a properly trimmed fire-formed case.

An alternative to using Cerrosafe is to make a sulphur/graphite cast. To do this, make up a mixture containing a ratio of approximately two-thirds sulphur to one-third powdered graphite. Sulphur requires a much higher melting temperature than Cerrosafe but it has the advantage of neither growing nor shrinking once the cast has set.

A 4-lb. sack of sulphur can be had cheaply at the garden centre. Clean and degrease the chamber, put a paper plug about 1/2" into the rifling, drop a piece of cotton string into the chamber, do not use synthetics, have a wood dowel longer than the barrel and of smaller diameter on hand. Place some sulphur in a small pan with a pour spout, using, preferably an electric hot plate, slowly heat the sulphur until it melts, do not let it catch fire, the smoke is poisonous. Stir in the powdered graphite and pour in enough of the liquid mix to just fill the chamber, wait until the cast is completely hard, this will depend on how large the chamber is, which governs the mass that has to cool down. Carefully push on the cast with the dowel while firmly pulling on the string; it should come out easily once it starts to move.

As noted, unlike Cerrosafe, sulphur cast dimensions of the chamber do not change at all over time, so how soon you measure the cast is not important. Sulphur is one of the few elements that do not change dimensions when going from a liquid to a solid state. Casts made with sulphur do not change shape or dimensions even after many years. Molten sulphur can also be used to set machinery anchor bolts in concrete.

The inclusion of graphite allows the casting to release very easily after it cools. The best ratio, is somewhere between 10% and 30% graphite. Use a piece of poly tube through the receiver, pressed firmly against the rear of the chamber to keep from spilling it all over. Stick a funnel in it and pour until you see it in the tube.

blackthorn
04-28-2009, 11:28 AM
What follows is the information I have accumulated on using Cerosafe in chamber casting. I also include information on making chamber casts with a sulphur/graphite mix. This mix seems to have some advantages over Cerosafe as it does not change "as cast" dimensions over time. Hope you find this usefull.


CERROSAFE:

While the makers of Cerrosafe produce several different alloy combinations, the one we are concerned with consists of the following percentages: Bismuth - 42.50, Lead – 37.70, Tin – 11.30, Cadmium – 8.50. Note: Cadmium is very toxic so use good hygiene and avoid breathing the fumes. We all know the harmful effects of inhaling or digesting lead. Cadmium, is even worse. Its compounds are extremely toxic even in low concentrations, and will bioaccumulate in organisms and ecosystems. So use similar but even greater caution when working with Cerrosafe as you would when handling lead.

Notes:
 Melts between 158 and 190 degrees Fahrenheit
 Should be melted in a clean iron ladle without direct flame on the product.
 The chamber being cast should be cleaned thoroughly and a thin coat of oil or graphite applied.
 Reusable

Contraction - expansion factor versus time, after casting, measured in inches per square inch:
 2 minutes -.0004"
 6 minutes -.0007"
 30 minutes -.0009"
 1 hour +-.0000"
 2 hours +.0016"
 5 hours +.0018"
 7 hours +.0019"
 10 hours +.0019"
 24 hours +.0022"
 96 hours +.0025"
 200 hours +.0025"
 500 hours +.0025"

Basic Instructions:
 Plug the bore about one inch ahead of the throat of the firearm using an appropriate size cleaning patch.
 Pour the molten alloy directly into the chamber until full and allow it to cool, it will turn a shiny silver color. As soon as it has cooled enough that it is no longer a liquid (and doesn't present a burn hazard), run a rod into the bore from the muzzle and tap the casting out of the chamber. Take care not to overfill the chamber as the alloy will then run into the locking lug area, making removal extremely difficult. Any recessed areas can be plugged with modeling clay prior to pouring.
 During the first 30 minutes of cooling Cerrosafe shrinks and then begins to expand. At the end of one hour it should be "exactly" chamber size. The Cerrosafe will manage to find its way into some pretty tight places so it is easier to have the rifle stripped to the frame prior to commencing the job. Clean the chamber, lightly oil it (then wipe it out with a patch), plug the barrel at a point that allows the formation of about an inch of rifling to be included in the cast, and cast it.

Cerrosafe's melting point is below the boiling point of water so you can use a plastic funnel with a short length of vinyl tubing to get it into the chamber. The tubing should be just long enough to reach the chamber with the funnel set through the back of the receiver. Heat the Cerrosafe in a skillet ashtray, or other container with a pouring spout, over a heat source set on low. As soon as the cast has set up, push the “plug-patch” along with the casting out of the receiver with a wooden dowel.

When making a Cerrosafe cast of a high-wall rifle, the action must be disassembled and, depending on when the cast is measured, a mathematical adjustment (see above chart) may be necessary due to material expansion. Also, when using Cerrosafe to determine case OAL, headspace must be measured separately, which can be somewhat complicated.

One additional excellent use for all of the low-melting-point alloys is to “fixture” small, delicate and/or odd-shaped parts for filing or machining.

If you want to confirm the accuracy of the casting, to determine the expansion across the diameter of the casts, compare the cast to a soft lead slug, which has been driven into the throat and bore. To check length expansion, use the following technique.

The rifle is loaded with a case almost filled with lead, that has been previously fired in that firearm but left unsized and the action is closed. With the butt of the rifle resting on padded carpet and the muzzle pointing up, thick soft lead wire is dropped down the bore. Using a steel rod longer than the bore and slightly smaller than the bore diameter, pound/drive the wire into the unfilled mouth of the case and fully expand it into the chamber and throat by “pounding” on the end of the rod with a hammer. The resulting case and formed end provide a very accurate representation of the chamber, freebore, throat, land and grooves. Simple precautions such as spaced areas of tape placed around the rod will eliminate possible rod-damage to the chamber and bore.

Because a “slugged image” of this area made in this way does not shrink or expand over time, this method is cheaper, simpler, easier and more accurate than using Cerrosafe. In addition, a measurement from the rear of the rim to the start of the transition step includes the actual headspace of the rifle and provides the overall length (OAL) of a properly trimmed fire-formed case.

An alternative to using Cerrosafe is to make a sulphur/graphite cast. To do this, make up a mixture containing a ratio of approximately two-thirds sulphur to one-third powdered graphite. Sulphur requires a much higher melting temperature than Cerrosafe but it has the advantage of neither growing nor shrinking once the cast has set.

A 4-lb. sack of sulphur can be had cheaply at the garden centre. Clean and degrease the chamber, put a paper plug about 1/2" into the rifling, drop a piece of cotton string into the chamber, do not use synthetics, have a wood dowel longer than the barrel and of smaller diameter on hand. Place some sulphur in a small pan with a pour spout, using, preferably an electric hot plate, slowly heat the sulphur until it melts, do not let it catch fire, the smoke is poisonous. Stir in the powdered graphite and pour in enough of the liquid mix to just fill the chamber, wait until the cast is completely hard, this will depend on how large the chamber is, which governs the mass that has to cool down. Carefully push on the cast with the dowel while firmly pulling on the string; it should come out easily once it starts to move.

As noted, unlike Cerrosafe, sulphur cast dimensions of the chamber do not change at all over time, so how soon you measure the cast is not important. Sulphur is one of the few elements that do not change dimensions when going from a liquid to a solid state. Casts made with sulphur do not change shape or dimensions even after many years. Molten sulphur can also be used to set machinery anchor bolts in concrete.

The inclusion of graphite allows the casting to release very easily after it cools. The best ratio, is somewhere between 10% and 30% graphite. Use a piece of poly tube through the receiver, pressed firmly against the rear of the chamber to keep from spilling it all over. Stick a funnel in it and pour until you see it in the tube.

ghh3rd
04-28-2009, 05:13 PM
It sounds like a tube of graphite that one would use to lubricate a door lock would be enough to mix with some sulphur ... is this correct? Is sulphur safe for all types of gun barrel steel? I may try to find some sulphur.

I have been meaning to ask, when you are pushing a slug through your bore, does the rifling cause it to rotate as it passes through the rifling?

Randy

JeffinNZ
04-28-2009, 06:25 PM
BLACKTHORN: A man after my own frugal heart. I have a half gallon tub of graphite powder I use for coating homemade shot and will get so sulphur at the weekend! Good man. Really appreciate the tip especially since today my NZ dollar is buying only USD0.56.

ghh3rd
04-29-2009, 11:47 AM
Found another reference to sulphur/graphite on Google:
http://books.google.com/books?id=7Ab12fHr8y0C&pg=PA207&lpg=PA207&dq=graphite+sulphur+slug&source=bl&ots=uduB_MtZ6l&sig=_o3EqwGVcY1ZMVtNYW6X6B-A3dA&hl=en&ei=Qnb4Sa6YBYvItgf5z72uDw&sa=X&oi=book_result&ct=result&resnum=1

HangFireW8
05-03-2009, 06:59 PM
A 4-lb. sack of sulphur can be had cheaply at the garden centre.


Uh-huh. What country, or decade, was that written in?

-HF

ghh3rd
05-03-2009, 09:45 PM
It looks like something like this may be what the author was speaking of. Perhaps blackthorn can say. Also, I was wondering if the graphite from one of those plastic tubes used to lubricate locks would work.

http://www.gardeners.com/Garden-Sulphur/35-739,default,pd.html?SC=XNET8419


Randy

blackthorn
05-04-2009, 09:56 AM
Randy said: It looks like something like this may be what the author was speaking of. Perhaps blackthorn can say. Also, I was wondering if the graphite from one of those plastic tubes used to lubricate locks would work.

http://www.gardeners.com/Garden-Sulp...ml?SC=XNET8419

Yes and yes. I have had my bag of sulfur for a lot of years! Have a great day.

dakotashooter2
05-04-2009, 12:34 PM
I just about choked when I saw the current price of cerrosafe. $20 for a 1/2 lb ( or more) ????????? Just a couple years back it was around $7-$8.

Slow Elk 45/70
05-04-2009, 01:02 PM
GHH3rd, yes the slug will follow the rifling

hiram
09-28-2009, 09:14 PM
Did my first cerrosafe casting -- 45-70 chamber. I had to wait 20-30 minutes for shrinkage to hammer the plug out. I was nervous. I came out with a few voids.

XWrench3
09-29-2009, 08:00 AM
actually, there really might be a reason to save one casting (the best one). if you shoot the heck out of one gun, as time goes by, you would be able to "track" the throat erosion as you go. keep one casting every 1000 rounds or so.