Tube bending with ice?

[KemppiFrog]

Friend is restoring a RN small planing pinnace. Dates from the early 50s. He has fixed the hull and found an original Coventry Climax 2T diesel. Only 4 left, one on HMS Belfast.
I am due to fabricate the rudder soon. But get frequent requests for advice.
The exhaust needs a cooling sheath. Idea is to wrap copper tube round the 2" pipe to cool it before injecting the water into the pipe as a silencing and cooling final stage.
He aims to fill the tube (12mm) with water and freeze it. Then wrap it round the 2" pipe.
Any body tried this, or has a view?
KF

 

[ibrooks]

Don't they do trombones this way but use soap of some sort in the water?

Iain

 

[outofthefire]

Use silver sand its much easier and a lot less mess.

 

[Luke]

Why wrap it round? Its very common to inject the cooling sea water straight in to the exhaust, typically as part of the fitting that goes from the exhaust manifold to a length of tube to take the exhaust pipe. Usually accompanied by an anti siphon valve and muffler.

 

[KemppiFrog]

Why wrap it round? Its very common to inject the cooling sea water straight in to the exhaust, typically as part of the fitting that goes from the exhaust manifold to a length of tube to take the exhaust pipe. Usually accompanied by an anti siphon valve and muffler.

Yep, but he is trying to keep more like the original, which was dry with a silencer up to near the transome. On that, it had a concentric copper exhaust pipe with some complicated flanges to mate the sections.

 

[superls]

copper tube should bend cold and empty, i have some 1/2" stuff here that does, its made for purpose, slightly softer alloy and a thicker wall

 

[Tigman]

I agree get a roll of soft copper and it should wrap round , if your gentle and the radius isnt too tight !

 

[FranV8]

I've seen this done in the Netherlands with stainless tube to make large, coiled concentric tube heat exchangers for the dairy industry. From memory there were actually several smaller tubes inside one larger outer jacket.

 

[malfazer]

a lot of wind instruments are made this way filled with water when frozen bend over wooden formers you can bend very tight curves this way in copper and brass

 

[KemppiFrog]

Thanks for the replies,
The tube is 12mm on a 50mm diameter pipe. I have backed off with the advice and will let him get on with it....
So far, his work is great. Done lots of classic cars, so no surprise. He is just stumbling on the idea.
KF

 

[Shox Dr]

You need to use ceabend or WS8, otherwise you'll never successfully bend that

 

[KemppiFrog]

Well, the guy tried it, and said it works a treat, very easy.