Just got a casting......

[Brad Foust]

I just bought a nice bronze cannon rough casting at the Fort Frederick trade fair.
The bore is about 1 3/8" and its gonna make a neat cannon.
Its approx 28" long and well over 3: OD.
I think that I am going to make a full sized colonial type swivel gun in stead of a scale model of a cannon.
Anyway, some of the casting has a few pretty large pits and flaws. Far too deep to file or grind out.
I am wondering if it might be possible to use a torch and brazing rod to fill some of these??
Or might there be a solder that has similiar color to brasss or bronze.
I could even use spot putty and fill the small voids and paint the cannon. But then of course I'd lose the brass color??
Any ideas or tips on how to fill these pits???
Thanks

 

[hawkeye2]

You can braze the pits but the brass filler rod may not match the color of the base metal. Brass wicks heat away from the work area fast so it requires a lot of heat input much like brazing cast iron. Preheat the entire casting as hot as you can get it and don't stop brazing till the entire job is done.

If the barrel has visible flaws I hope you do NOT FIRE it without lining it. If there are visible casting defects there are most certainly hidden voids/flaws. A liner should be of barrel steel with a threaded & welded breech plug and should be a tight fit in the barrel casting.

 

[Brad Foust]

Yea,
I been wondering about the barrel??
There are no big flaws. It's like a sand casted butt plate. But a few are a little deeper than I would want to file down the entire surface to match.
If I put a liner in at the size the bore is now, then the bore of the liner will be really smaill, probably well under an inch.
That would defeat the purpose of my purchasing this thing.
I might be able to have the bore in the casting enlarged and put a larger liner in it.
My other choice is to "PROOF FIRE" it with a larger charge and see what happens?
I been filing on it for a few hours and it is cleaning up fairly decent. There will be some pits, but I'm not going to try and fill any of them.
Thanks for the input

 

[voltigeur]

if you want to do a proof test,with this size (35mm),the load is 156 grams of pnf4 with a bullet of lead (236 grams).
be carefull if you do it yourself,no error is allowed.
In belgium,it's the max caliber than the proof bench can tested.

 

This piece should be x-rayed for voids, then if acceptable, I would recommend a heavy sleeve and light salute loads. NO LIVE FIRE.