Old style rotating band installation.

[DEADLINE222]

I have done plenty of modern rotating band replacements, but I have yet to do anything older.

My first older project will be a 1880's US 6 pounder, common. I will be using copper, and I am intimidated by what seems to be a lack of surface to hold the copper, unlike with modern projectiles.

I would like to keep the rotating band trench original, and not add areas to grab the copper.

I have read old books describing how the process was acomplished at the factories, but I am wandering how I can be succesful in the garage with 12 ton press and existing tools?

 

[HAZORD]

Not knowing how much smaller in diameter the groove is for the band compared to the projo body, it is hard to judge. If the groove is deep you can reband by wrapping a copper strip around the projo to bring the diameter up to at least the diameter of the projo body. Then you heat shrink a copper ring over that strip to hold it in place, and you then turn down the profile on the outer ring to match the original cross section desired. That is one way.

Another way is to cut a copper strip to be the new band on a bandsaw. Heat the copper hot (which is tough, because it pull the heat away. Use a vice to hold the beginning of the strip in the groove, then slowly hammer and compress the strip around the projo into the groove. It hammers and bends easier when hot. When the strip starts to meet up with the beginning, trim its length to meet up so you can do a Vee-butt weld to close the ring. If you have a water cooled Tig you can Tig weld it using normal copper home wiring, but you need to really heat the copper up with a torch, because it is a bear to get hot enough to weld. You need a water cooled torch, due to the heat required from the tig. Be careful not to melt your tungsten into the copper, or the arc will keep jumping to that. If you are set up for Mig, you can also weld copper that way, or get a copper/bronze stick welding rod and do it that way. Turn the outside to desired profile.

 

[torch42]

Ive replaced quite a few copper driving bands and you'll need access to a lathe and have a hydraulic hose doctor in your town(hydraulink,enzed,parker etc),I used the replacement blanks for copper soft hammers(available at most good engineering supply places)and bored the ID to about .1 - .2 of a mm over size(don't worry about how much material you have on the OD as yet(better to have too much than not enough)and part off at the exact length of the driving band groove,take machined ring and projectile to your hose doctor and get him to very carefully swage the ring into the driving band groove then back to your lathe to machine down to correct profile and OD(this is why more material is better to avoid leaving hose crimp machine marks on finished product)then I left the completed projectiles outside as I lived in a highly sulphurised atmosphere in my old home town and after a few days it had a nice aged look,apparently you can reproduce aging patina on copper and its alloys by using salts but im not familiar with that method.

 

[Mag]

Drive band

Hi Deadline
The attached jpg shows a close up of an unfired 6pdr driving band to help with profiling