| Howdy Alan,
Ok, now I am a machinist by trade, and I am sure there are several of us in the forum, that being said, what I have gotten out of your description you have an approx 1 1/2" dia. tube you need to flange on one or both ends.
I can see in my mind several different ways of achieveing (sp) this.
1. the method you mentioned with a press whereby you create a die and punch for the press.
2. creating a die and punch which can be used in conjuction with a hammer.
*3. cutting a flange and "silver soldering" it into place on the tubing.
**4. single piece construction using 2" dia copper rod in a lathe.
*In number 3 above, you would need to cut a flange the size required from a sheet of copper of the appropriate thickness using a lathe, "milling machine/flycutter combination" or even a vertical bandsaw (if precision is not really important) and then using silver solder (not lead) and brazing the flange in place on the end (or around the outer edge) of the tubing.
Silver solder is very strong and in my former occupation as a machinist building power distribution transformers, I often used it and have seen that the copper itself will fail before the silver solder joint fails provided it was brazed properly.
Now I will say that single piece construction would be "optimal", but failing that, the silver solder method would be the way to go. There is alot less "manufacturing" involved in the brazing method and depending on whether it was a butt joint or the flange was slipped over the outside edge of the tubing would really make no difference....again, the silver solder joint, if brazed properly will be stronger than the copper.
One other aspect of the silver solder brazing method i should have mentioned above is that the solder will fill any void you may have between the two pieces of metal and being silver, it will have a much higher heat tolerance than ordinary tin or lead core solder (upwards of something along the lines of approx 1200° F).
The only drawback I might see in this method would be the availibilty or lack thereof.....of an Oxy-acetlyene torch. You will need this in order to use the silver solder.
**In number 4 above, would be the construction of the tube with flanging on the ends as needed by constructing the entire one piece unit on a lathe using 2" dia. round copper stock.
You would turn down the external dimensions as required including both flange thicknesses, seperating the piece from any excess stock, "re-chucking" the entire piece then "boring" the internal dia. as needed, allowing you to create as thick or thin a wall as you want.
Now lets say you dont have a lathe or an acetylene torch, I am sure that a local machine shop would build this boiler, flanges and all, to your specifications, for a few dollars plus the cost of the small piece of copper rod (which would only have to be a piece of scrap that you can pick up at a salvage yard).
Like bunker said, these are just a few thoughts, there is always the method of "rolling" the flange onto the tubing using a lathe, but that is way to hard for me to describe much less instruct someone on how to achieve the desired results. And not knowing your machining abilities, I wouldnt even begin to try to explain it.
I hope this has provided you with some usable options, let us know what you finally decide as well as the outcome.
Have a good day,
Greg aka GW |