Suitable alignment tool

[Lxmanager]

Question.

I am trying to tack weld 450mm x 1mm thick end caps onto a 1mm thick pipe, currently having to do this un-aided by hand with the pipe in the vertical, manipulating the joint with one hand and tacking with the torch in the other, which is taking quite a long time.

Does anyone know of a suitable clamp/alignment tool I could use to get the two pieces round and keep the circ seam in line while tacking? I have seen many pipe clamps on the internet but they always seam to too big and heavy for my application, they seam to be for heavy walled pipes.

The clamp/alignment tool has to be external because I cannot get anything inside the pipe.

Thanks

 

[hotrodder]

For production work... A piece of tube (or roll some strip) that's a snug slip fit over the tube, cut some notches in one end (like a castellated nut) to give access to the joint and it'll keep the cap concentric. If needed could place a piece of bar or some other weight on the cap too keep it from lifting or fold the castalleted bits 90* and jubilee clip it to the tube

One off things i just use some tape leaving the backing in place where it crosses the joint

 

[Hitch]

Is this Tig, or Mig?
What kind of joint is it, outside corner, or is the edge of the disc flush with the outside of the cylinder...not much different in 1mm

Mig is easy, just use a strip of thin sheet to rest the back of the end cap on, tack in a few places, and pull the strip out, tack the back, just use your arm to pull it into place. 1min at the most.

Are the caps laser cut? Could you get some alignment tabs put on?

Theres loads of ways for production, just depends on what your finished article needs to be like.?

 

[chap]

Piece of angle clamped on the outside so it protrudes above the end of the tube, push the disc into the corner, hold lightly and tack in 2 pos, remove angle to place third tack.

If this is a one-off type job and it's largish, you could use a ratchet strap to clamp a couple or three bits of angle to make the placement easier/more accurate.