Does anyone make a steel 8 or 10 inch mortar barrel ?

[entsminger]

Well from what I'm hearing a steel barrel ( even for big mortars?)is much preferable to a cast iron one as far as strength or safety reasons, etc. I've emailed quite a few cannon makers who were listed on the stickys and while I have not recieved answers from all it seems that most makers of bigger 1861 style 8 or 10 inch mortars cast the barrels in gray iron? Does anyone know of a manufacturer who makes these big mortar barrels in steel?
   
  Scott

[Cat Whisperer]

If I were doing it, I'd have it made locally because I know a machine shop that has a good large vertical lathe. That would give me a choice of material as well.

Then the only issue is attaching the trunions.

[entsminger]

I'm new to this so forgive me If I don't sound like I don't know much about making mortars ( and I don't) but wouldn't the whole barrel ,trunions and all be cast and then machined as one piece or is that harder to do if it's made of steel?

  Scott

[GGaskill]

Steel casting is a lot more specialized than iron casting so you don't find a lot of small scale steel casters around and those that are in the field are not cheap.  
 
It would be relatively easy to fabricate an 8" or 10" M1861 mortar but getting the trunnions to fair into the barrel would be a real pain.  I wouldn't bother unless using Bondo or some other body filler.  Welding the trunnions on would be more than adequate if properly done.  Just lots of work so lots of labor expense.  And the average shop is going to be stretched to machine a large diameter barrel.

[Cat Whisperer]

I'm new to this so forgive me If I don't sound like I don't know much about making mortars ( and I don't) but wouldn't the whole barrel ,trunions and all be cast and then machined as one piece or is that harder to do if it's made of steel?  Scott

That's the way and the reason casting is done.  It is a process that simplifies things by making an assembly in one piece - the added cost is making a complex pattern and a little machining here and there, but the payoff comes from making a bunch of them with a reuseable pattern from cheap materials (cast iron is very cheap).  

The alternative is to put together an assembly - much more machining of every part, fitting the parts together, fastening the parts together - time - time - time!  More costly WHEN you make a bunch of them.  If you're only making one - machine it - cheaper than casting ONE.

[Cat Whisperer]

...  And the average shop is going to be stretched to machine a large diameter barrel.

Right on the money.  I happen to know ONE shop that happens to have a vertical lathe that can go perhaps 24" in diameter and 3 to 4 feet long.  Not the usual lathe.

[Cat Whisperer]

...  It would be relatively easy to fabricate an 8" or 10" M1861 mortar but getting the trunnions to fair into the barrel would be a real pain. ... .

AND in the same respect, when a business does the casting, they probably invest also in the lathe that will do the trunions - a huge fixture that spins the tube on the axis of the trunions - quite a sight to see even in pictures.

[Third_Rail]

I went to class with someone who has a 6' diameter capable lathe for stock up to 13' long.  :eek:

Now THAT is a lathe.  :grin:

[Cat Whisperer]

I went to class with someone who has a 6' diameter capable lathe for stock up to 13' long.  :eek:

Now THAT is a lathe.  :grin:

YEA!!!   Mine is only 13x38 (in inches)!