Back in my early days with SCBG I remember helping J.C.White bend barrels for our gun systems. I've gone through my notes but so far haven't found the low temperature "lead like" alloy that we used to maintain the ID of the barrels when we bent them. It's melting point was somewhere around the boiling point of water. Does anyone know the name, brand or otherwise of this alloy and where I might order or pick some up? I think it might have been called "Cerro.....something", maybe, I don't know. Also what are the spec's of the barrel material itself. I know its stainless steel, but what type....304? and wall thickness? I've got a lead on what looks to be perfect material at my local surplus metal mart.....AT SCRAP METAL PRICES!! In twelve foot lengths....that's a lot of barrels...if it's the right type. Fingers crossed.
Be glad to share notes and drawings once I get everything found and sorted out. A lot of my stuff has been in storage for years and years. I'm sorting through material price sheets and construction "How-To" outlines from the early 90's. I think I have a copy of one of the first construction manuals for R/C Model Warship Combat written by Martin A. Hayes. I need to either scan or redraw the diagrams in a CAD program. Now bear in mind the vast majority of this stuff is twenty some years old by now so I'm not sure just how helpful it will be for folks today. We were doing a lot of experimenting and a LOT of trial and error, mostly a lot of trial and a fair amount of error, but it was seriously fun. There was no one that built ready made systems back then. If you wanted to play you had to build it yourself. So some of our stuff was pretty rough.
You have a wayback machine there, so I am waiting in anticipation. Theres been a lot of balsa gas and balls expended since the 90's and it will be very interesting to see how retro the "old stuff" really is.
I remember seeing a tube bending process where steel balls were pressed though the bend to stretch the bent section back to the desired radius. The first one or two balls was the desired diameter and the followup balls slightly smaller. An enterprising fellow could build a jig to mass produce barrels. I think it would be faster and cleaner than the Cerrobend method.
I remember JC and I trying that method. Unfortunately the SS tube can still kink where the balls aren't supporting the tubing sides and give you kinks and thus jams. Using the Cerrobend doesn't leave any unsupported sections of the tubing. Getting the Cerrobend out afterwards is actually pretty easy. Just drop the bent barrels in a pot of boiling water (BTW...NEVER use this pot again for cooking food!!!), pick up the barrels with tongs and letting the Cerrobend drain out. A quick run through with a tube brush and swab to insure all the alloy is removed was Easy-Peezy. Oh...and go with a good quality tube bender not something cheap and cheezy. Oh and we used a hot plate OUTSIDE of the house to do all this. Cerrobend (and other alloys like it) has Lead and other nasties in it so treat it with respect and protect yourself. Don't touch it with bare skin or breath any fumes....use it outside in plenty of fresh air. It's not killer toxic, but it's also not a good thing to over expose yourself and other to. That might seem like overkill but better safe than sorry. As I remember we had very few failures using this method, though I do recall it was a mega bear bending the Cerrobend filled stainless steel tubes. This was the best method that we found back then. I have no idea how they bend tubing today. Perhaps someone can comment on that to bring us up to date?
Why wouldn't there be a mini pipe bender? Just thinking out loud with all the 3D printers and interest in the hobby for over 30 years. I know there are pipe benders for water lines. I thought those kept the ID and OD constant. Maybe I'm just wrong?
Ooooh I see what your saying. Still...that would not be easy dealing with Stainless Steel. SS is not extremely malleable and doesn't like to be played with too much and believe me....pushing ball bearings through bent stainless steel would be a mega-beaotch! I know the Cerrobend stuff works and works well. It's not difficult to do and gave us very few failures. How are folks bending and forming barrels today??
If you build your cannons for it, use brake line for your barrels. Bend it in the same tubing bender, no special stuff required. Replace barrels after 1.5 to 2 years of heavy fighting.
The stainless steel we used for making barrels back in the 90's was much heavier than the material I've seen used for brake lines. I don't recall any of the barrels we bent back then "wearing out" and by using Cerrobend to maintain the ID dimensions there were very few rejects in this process. So how are barrels being bent today by most folks?
Maybe one of @Stuart @DarrenScott @Kotori87 @Gascan @buttsakauf or @Rob Wood can be of assistance in answering. Edit; i see kotori already indicated just using a bender above
From most of what I have read recently, it seems that the majority of guys are using the material/ method Kotori mentioned, Use standard brake line and use a standard bender. Quick, easy, cheap , and within the means of most everyone. Some have gone the route of close tolerance stainless barrels, but it seems the masses are moving away from this for a few reasons: It takes more effort, time and expense to bend the stainless. Not insurmountable by any means, just extra effort. I have also seen several mention they had dents cause by battle damage in the close tolerance barrels (which tend to be a thin wall thickness to make them bendable) cause them to jam. In answer to your question in the original post about material specs on stainless, I *think* they were using 304 SS smooth bore tubing, 5/16" OD with a .028" wall thickness. I was going to go that route, but used brake line to test with and am happy enough with it to skip the stainless barrels. If they wear out in a couple years, I will remake them.... with brake line it is so cheap and easy.... it could probably even be done pond side, if someone had the bender and cutter with them. Not that I would do that, but it would probably not be out of the realm of possibility.
