Aluminum Tubing

Date 11-25-2002 19:37

If you use lap weld it won't be any problem for making the exposed weld, i.e., that on the tube ouside. However, how are you going to make the hidden weld, i.e., that on the tube inside?
If the tube is extruded, would it be possible to make it seamless? If seamless steel pipe is made by extrusion, it should be possible to make also aluminum tubing.
Giovanni S. Crisi
Sao Paulo - Brazil

By geof Date 11-26-2002 16:38

Thanks for your response C.S. Crisi,
I should explain that there is no interior welding required on this tubing. This aluminum tubing is only 0.035" in thickness and will end up having a layer of polyethylene tubing on its inside as well as the outside of the aluminum tubing. The aluminum is used to make the pipe more rigid. This tubing can be welded two ways, butt or overlap. Not being a welder myself I need the expertise of you experienced welders to give me your comments on which is the better weld method.
Thanks!

By Niekie3 (***)

Date 11-26-2002 18:03

For ease of welding and consistency, a lap joint will be better. This will however be weaker if the tube is loaded accross the weld because you will have an assymetrically loaded weld.

At any rate, welding such a thin Al will be very difficult especially to perform a butt weld.

Regards
Niekie Jooste

By jwright650 (*****)

Date 11-26-2002 19:45

I would have to agree with Niekie Jooste, the lap joint would be your best option due to the thin wall.
Let us know how it turns out,
John Wright

By G.S.Crisi (****)

Date 11-26-2002 20:46

Let me see if I've understood exactly what you're meaning.
In a lap weld, the ends of two different plates overlap and there are two welds to be done, one on each side of the overlap.
In this case, what overlap are the sides of the rounded strip the tube will be made of. You say that only one weld will be done: the one exposed, i.e., the one located on the tube outside, right?
In this case, let me tell you that back in my days of erector engineer I installed thousands of Admiralty brass condenser tubes which were 18 BWG in thickness (i.e., not too different from yours) which were resistance welded. Resistance tube weld is a butt weld. Wouldn't it be possible for you to resistance weld your tubes? Or, since they will be extruded, make them seamless, as I said on my first answer?
Giovanni S. Crisi