Boomerang1

Calling those wiser & more experienced than me.

I'm building a scratch built jet & the jet pipe is a little too short (my bad).

It's a Wren thrust augmenting pipe but it only needs to be extended about 2 inches to clear the back of the model.
Is there any reason it cannot be extended with another strip of stainless wrapped around the outside of the pipe
& secured with some stainless pop rivets inserted from the inside of the pipe?

The outer pipe is litho as per Wren instructions, no issues there.

Thanks in advance.

Kevin_W

My Feedback: (1)

I have extended a pipe before, but I spot welded the extension in place.
I think using pop rivets could result in a several possible issues.
(1) the rivet tool is likely to be too big to fit inside the pipe without distorting it quite a bit.
(2) It is possible that the rivet heads in the hot gas flow could cause uneven heating of the pipe and lead to warping and/or failure.
(3) Your extension is still going to have a seam that will need to be joined. If you do that with pop rivets you are going to end up with a lot of rivet heads in the flow at the very back of the pipe.
I would look for someone who can spot weld it for you.

causeitflies

A couple inches short shouldn't hurt anything. If you're worried put some heat protection above the pipe in case of a hot start.