Sand casting a brass barrel

[Cannoneer]

I came across this YT vid on the net while looking for other info on brass cannons, and found it interesting.
A question for Max Caliber: Does this gent know what he's doing, and what is the powder that he
pours in the mold?

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ETA: I embedded the vid, for some reason I couldn't do it when I opened the thread.

[GGaskill]

... what is the powder that he pours in the mold?

Generically, it is parting compound.  It is commercially available; old time foundrymen used the dust from high rafters.  I used talcum powder.  It is something to keep the sand from the upper layer flask from sticking to the sand in the lower flask so the pieces can be separated without destroying the mould.

Does this gent know what he's doing?

More or less.  I would have a second riser on the mould and drill the barrel in a lathe but maybe he doesn't have a lathe.  And I am not thrilled with his method of removing and replacing the cover on the furnace.

[KABAR2]

The powder he is using is called parting powder, it keeps the two halves of the mold from
sticking to one another, some people use a model that is halved and mounded on a board and
each half of the mold is made on one side of the model this makes producing many copies easier,
the use of a model as he is doing is more old school it takes a little more time, I like the use of the
weights while casting to prevent the upper mold from floating, the excess metal poured can actually
lift the upper flask and cause distortion, the odd thing is no second riser to allow gas/air to escape the
mold. it looks like he made two molds for casting the cannon..... why else tamp the sand twice? and the
first one did not have a way to pour, when he is first heating the metal there are two flasks on the ground and
it is day light, when he does his pour it is night and only one flask....

I see GGaskill already covered the same ground, the only thing I will add is I hope he is actually casting bronze
and not brass as stated........

[gulfcoastblackpowder]

...
More or less.  I would have a second riser on the mould and drill the barrel in a lathe but maybe he doesn't have a lathe.  And I am not thrilled with his method of removing and replacing the cover on the furnace.

He cleaned the trunnions with a lathe, though perhaps it doesn't have the capacity for the boring?

Casting your own cannon is a neat project, and it has been fun watching our own home foundry members (Dan and Gary).  I would have liked to see some detail in the cannon that would indicate that it had to be cast, since this one was relatively plain and the whole thing could have been made on a lathe.

[thelionspaw]

Nice project...including the video...but the best part of this posting is...the knowledge of our own posters. You men never cease to amaze me with your diversity.

[Max Caliber]

The guy used a one piece pattern which makes the mold making process harder to do than using a two piece pattern, but maybe that was all he had to work with. I make all barrel patterns in two pieces that part down the center and I incorporate the sprue into the pattern along with a long tail piece on the cascabel end to hold the casting in the lathe. I cast barrels vertically through the end of the flask. This makes for a much stronger casting. One only needs a small amount of parting dust between the two halves of the flask. I use a sock to hold the parting dust and shake it onto the flask, then blow away the excess. There is no need to put parting dust on the pattern. Looks like the guy has a nice set-up and a good looking furnace. Was interesting to see he cast a separate piece to hold the barrel for drilling.

[Max Caliber]

After looking at the video again, I see that he buried the one piece pattern half way into the drag (the bottom part of the flask), then he made two copes (the top part of the flask) the first without a sprue because it would become the drag of the second flask. Then he put his pattern in the second drag, then made a new cope with a sprue. That way he did not have to go through the process of burying the pattern in the second flask.  Anyhow, In the process he would have discarded the first drag. Part of this process is not shown.

[Cannoneer]

Gentlemen: Thanks for the information.
Max; I think I understand what you're saying about using the cope without a sprue to be used as the drag (bottom half of the flask?) on the actual mould he used when casting. He did this because tamping the sand down around the one piece pattern in the cope would give a lot better detail than the way he had to place the pattern in the drag originally.
Most, if not all of the patterns I've seen were of the two piece variety; so if this caster had one of these patterns what exactly would change in the process he followed when making the two halves of the flask?

[Max Caliber]

The guy used a standard method for making a mold with a one piece pattern, this process is called the false-cope method. The process requires that a cope be made to hold the pattern so the drag can be made. The cope is then discarded and a regular cope is made to replace it. The process is more time consuming than making a mold with a two piece pattern.

[GGaskill]

I would have liked to see some detail in the cannon that would indicate that it had to be cast, since this one was relatively plain and the whole thing could have been made on a lathe.

The primary difference is the trunnions are integral with the barrel in a cast barrel.  This also makes it harder to clean up the casting between the trunnions.

[Cannoneer]

Thanks, Max.

Here's a short vid from the same home foundryman showing him set up his furnace, and it also shows him using old brass plumbing pipe for this project (whatever that may be). By the names in the credits I'd guess that these videos are from the general area of Dan's corner of the world.   

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[ShadowMover]

Some of the 'brass' seen in the crucible looked like some fire department fittings from old fashioned hose. Here in the US they were made of bronze, even though they were called 'brass' by the firemen. They use an aluminum magnesium alloy here  (USA) now. Anyway all I'm saying is it could be bronze in the crucible. Bronze is just about anything alloyed with copper. Tin and copper was the old standard bronze alloy. Now there is everything from phosphorus to silicon added, each with it's own characteristics. He may have scrounged the metal from a shipyard. Did you see those nice stainless steel tanks he made the furnace from?

Actually brass is a bronze too technically, since it is copper and zinc. The fact we didn't see any white smoke coming from his crucible makes me wonder if it was brass. When I've brazed with brass rod, and get it that hot there is plenty of zinc oxide white smoke floating around. I know, it's toxic, and I had too much heat on, but I'm just an amateur at gas welding

[gulfcoastblackpowder]

copper-zinc alloy = brass, copper-tin alloy = bronze

Either can have a bit of the other, but typically they're identified by their primary components.

[GGaskill]

Actually, modern practice is to call any copper alloy with zinc a brass and all other copper alloys bronze.  Not really sure that conveys much any more.

[dan610324]

from the names I would guess he is norwegian , so yes its close to me
its a pity to see how he used that stainless tank , could have been a high quality still 
but I love to see that he use an old boiler burner as the heating source
its the most economical way to heat a furnace
you can run it on diesel , kerosene , frying oil or almost anything thats combustable
if its brass or bronze is impossible to tell
today there are so many "bronze" qualities, many of them doesnt contain any tin
just to be sure I have always mixed my own stuff
ok the classic 90/10 isnt the strogest of them , but at least I know that Im historical correct and got an alloy that been used for cannons in approximately 600 years

there are lots of evidence for old cast iron cannons that burst when fired , but I havent soo far found any historical evidence for that happening on a bronze cannon with a service load

the cast iron cannons had a wall thickness of 1,25 to 1,5 times the chamber diameter
it didnt help , some of them burst anyway

so I feel secure enough with the 90/10 alloy
I would never use some alloy that I dont know what it is for a barrel casting