Exhaust bending... fun for all the family

[Grimly]

The Yoshimura trad way (and likely everybody else, back in the day)

https://www.youtube.com/watch?v=v8mMQbEkr8w

And the other way...

https://www.youtube.com/watch?v=HQH0PYPeCTQ

The second way is ruled out, as I don't have a bender that size, but the first way - I wonder if I can get enough heat from a propane/compair torch.

[JEEPRUSTY]

And now we make a test

[chuck hahn]

You wont get the required heat with a propane torch. That Rosebuds hitting well in to the 1750 to 2000 degree range.

[Nessism]

That bending method takes a LOT of heat. Wonder what the gas cost would be for a whole set. Very cool regardless. Makes we want to make my own header.

[Guest]

He doesn't mention it, but adding some dish soap to the water helps it move around easier during the bend and keeps things smooth. He needs a bender like that because he is using sewer pipe, 1.6mm = 0.062" wall which is at least twice as thick as it needs to be.


Mark

[Grimly]

That bending method takes a LOT of heat. Wonder what the gas cost would be for a whole set. Very cool regardless. Makes we want to make my own header.

Doesn't it just?
So very tempting. I'm trying to suss out what cheap and easily available fuel gases around here would do the job. Problem around here is the Oxy, acetlylene and others are sewn up in deposit and rental schemes that are aimed a fab workshops, not private users, and are too spendy.
Propane/compair would be cheap and easily got.

[JEEPRUSTY]

Well if they can make a katana in a small charcoal oven anything is possible

[Grimly]

Well if they can make a katana in a small charcoal oven anything is possible

Stage bending with a firebrick hearth will make most use of available heat, get it hot enough, plonk it back on the jig and move it. Need some / lot of practice, for sure; but pipe is cheap, and the rejects can go on a ratbike.

[Guest]

Doesn't it just?
So very tempting. I'm trying to suss out what cheap and easily available fuel gases around here would do the job. Problem around here is the Oxy, acetlylene and others are sewn up in deposit and rental schemes that are aimed a fab workshops, not private users, and are too spendy.
Propane/compair would be cheap and easily got.

I think Oxy/Acetylene is the only thing that will push that kind of heat. That is a big rosebud, too, much bigger than is used in most fab shop/welding work. I imagine the air temp in that small shop space got very uncomfortable with that rosebud blasting away like that.


Mark

[GregT]

If you're going to heat bend, what you need is a ring tip. Tubing ring about 6inch dia with at least three flame tips facing inwards. This ensures the whole circumference of the tube is heated as quickly as possible. A guy local to me used to do it using LPG - similar to propane I believe.Uses a LOT of gas....

Personally, I make up my pipes from bends, using oxy acetylene welding. usually 16G - or 1.6mm too. Even 2 stroke expansion chambers are made in 20G or .9mm. If you go much thinner than this they crack too easily - and get very hard to weld....

[Guest]

Personally, I make up my pipes from bends, using oxy acetylene welding. usually 16G - or 1.6mm too. Even 2 stroke expansion chambers are made in 20G or .9mm. If you go much thinner than this they crack too easily - and get very hard to weld....

Greg,

I can guarantee the header pipes on the Kerker my 1100E is wearing are no more than ~0.030" or so, they are far too flexible and ring at too high of a pitch for anything much thicker. 20ga sheet is only 56% of the thickness of your 1.6mm tube, that is a world of difference between the two even if it seems like very little. I agree that welding the 16ga is a lot easier than the 20ga.


Mark

[Grimly]

I think Oxy/Acetylene is the only thing that will push that kind of heat. That is a big rosebud, too, much bigger than is used in most fab shop/welding work. I imagine the air temp in that small shop space got very uncomfortable with that rosebud blasting away like that.


Mark

Yes, I suspect you're probably right. Unfortunately, the days of waving big-ass gas torches around are long behind me. It was great when someone else was paying for it.

If you're going to heat bend, what you need is a ring tip. Tubing ring about 6inch dia with at least three flame tips facing inwards. This ensures the whole circumference of the tube is heated as quickly as possible. A guy local to me used to do it using LPG - similar to propane I believe.Uses a LOT of gas....

Personally, I make up my pipes from bends, using oxy acetylene welding. usually 16G - or 1.6mm too. Even 2 stroke expansion chambers are made in 20G or .9mm. If you go much thinner than this they crack too easily - and get very hard to weld....

Again, the oxy-acetylene route is barred by cost. I'm looking at picking up one of those carbon-arc torches (the kind of thing that came with every cheap-ass welder in the 70s) as I used one for a while years ago and actually got to quite like brazing with it - it took a while, but I found the knack of using it. I've discovered that some carbon gouging rods are solid and v. cheap, compared to the genuine ones.