Will bending Galv pipe crack the galv?

[wookie]

I want to make a exhaust pipe for my Lister generator, as it will go out through the garage wall and down into an exhaust pit I want something that won't rust and end up looking an eye sore.

I was thinking of using galv scaffold pole, I have a mandrel bender that will make nice smooth curves but I was wondering will I crack the galv coating and end up with a pipe that will go rusty. As it is going to be concreted into a exhaust pit I don't want to something that will rot away in less than at least a decade or two.

I suppose I could get the pipe galvanized after bending it...

thanks

 

[brightspark]

I want to make a exhaust pipe for my Lister generator, as it will go out through the garage wall and down into an exhaust pit I want something that won't rust and end up looking an eye sore.

I was thinking of using galv scaffold pole, I have a mandrel bender that will make nice smooth curves but I was wondering will I crack the galv coating and end up with a pipe that will go rusty. As it is going to be concreted into a exhaust pit I don't want to something that will rot away in less than at least a decade or two.

I suppose I could get the pipe galvanized after bending it...

thanks

galv conduit doesnt crack when bent so should be ok

 

[brightspark]

scaffolding pole size soz couldnt resist

 

[Kent]

Zing is very ductile more so than the steel it covers so no it wont crack! I shouldn't galv anything that got that hot though especially things which also contain corrosive gasses I should just go stainless and be done with it.

 

[stormin]

The pure zinc top coating will likely crack and some will spall off. You'll be left with a zinc rich alloyed steel though which is corrosion resistant.

 

[CompoSimmonite]

I bend scaffolding 90 degrees without cracking.

 

[wookie]

Whats the exhaust pipe diameter requirements?

1" bsp coming off the exhaust manifold and the manual for the engine recommends 1" pipe for runs under 20ft and to keep it as short and straight as possible, but I was thinking it wouldn't do any harm to increase it as I will have to have a minimum of 10ft with at least 3 if not 5 90degree bends.

I shouldn't galv anything that got that hot though especially things which also contain corrosive gasses

Hmmm, Never thought of that, might be better in stainless then after all.

Stainless exhaust pipe can be had off ebay for not bad cash and the bends etc are readily available

Yeah I know but when you ideally need 5 bends, a flexy section and about 10ft of straight pipe it soon adds up.

So assuming I go with stainless, I take it I just need a reel of stainless mig wire and some argon gas ?

Previously I've tig welded stainless for years, never mig welded it thou. It's one of the only processes I've not done yet.

 

[wookie]

I bend scaffolding 90 degrees without cracking.

Argh! now I'm thinking of using scaffolding pipe again, seeing as it's only 20 quid for a 20ft length around here.

The pipe won't get much use, perhaps 5 runs a year, but it could be running for a couple of days constantly. The worst power cut we've had so far was 3 days in the middle of winter, but usually it's from a few hours to half a day.

 

[Wedg1e]

I bend scaffolding 90 degrees without cracking.

What, over your knee? Must have had three Shredded Wheat

 

[CompoSimmonite]

What, over your knee? Must have had three Shredded Wheat

Vegi diet

I've got a Hilmor hydraulic bender with formers up to 3"

 

[Mikey D]

Nope won't damage the galv , used to bend galv pipe all the time , crack on