hi there,

Any tips on how to weld exhaust pipes (1.6mm stainless tube) to a 12mm stainless flange? Its for a turbo.

I can join the tube together alright (a bit ugly but penetrations seems okay), but not sure how I should deal with the thick flange.

Welder is a clarke 110e, and I've got 0.8mm stainless wire and Halfords disposable Argon.

I am new to welding, so please be gentle.

Thanks,

Matt

Tack it and get someone to TIG it, results will be much better

Ben,

Do you mean it will end up prettier, or will it be functionally superior.

I don't mind a bit of grinding to tidy it up.

It seems a bit defeatist

Matt

Personally I would do as Ben suggested. I have MIG'd manifolds before and now I always find someone to TIG them for me. The whole job will be stronger, less likely to warp or crack and look 10 times better.

Try and make a welding template too - thick as you like to prevent warping.

[Edited on 29-12-10 by RazMan]

As per Raz, it'll be a much better job all round.

Current at maximum and work from the thick stuff to the thin, 110 amps is not very much power so go slowly!

Also work out you assembly, make sure that you do not end up with impossible welds by starting at the wrong point

Sounds like I should have posted this question before I started MIGing it.

Never mind.

Thanks for the advice guys. Anyone good at TIG in the Oxfordshire area? Don't mind going a bit further. I would want to pay for the work, but would prefer "while you wait" as I am impatient.

Matt

Would worth bolting the flange flat to stop distortion, won't seal if the flange warps due to welding heat

Regarding the warping of the flange.

I was planning on getting it machined flat after it was all welded up, that was why I went with 12mm to give a bit spare.

It is a very simple little manifold, 5 joints and then the merge and flange.

Anyway, here is a photo.




The flange welds on to the point where the 4 pipes all come together. The lengths are not equal, but neither is the manifold that Big-CC sell for the gsxr1000, so I am not too worried about that and they are similar in length (except 1 and 4).

The good thing is that there are not many welds and its all pretty open. Lots of grinding to do within the collector area too, but it keeps me out of the house!

Matt

[Edited on 30/12/10 by matt_gsxr]

Max setting, wire feed not too high. Focus the weld on the flange and gently touch in the pipe. It's tricky with the MIG not impossible. The biggest challenge is.that you are welding 12mm to 1.6mm nothing else. It's much easier with a tig as you have more time, if you know someone with a tig it would be worth tacking it up and having a nice job made of it.

quote:

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Originally posted by snapper
Would worth bolting the flange flat to stop distortion, won't seal if the flange warps due to welding heat

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That sounds like a pain.

Mine is simpler it is a bike engine, so separate flanges for each exhaust port. These flanges are not actually welded to the pipes.

The problem flange is for the turbo, its pretty chunky but I will bolt it to something to keep it rigid.

Thanks for all the help guys,

Matt

Update:

When people ask for advice, why don't they take it???? well in my case I had gone to far already, and I don't know anyone who can tig local to me.

The good news is that when the 12mm turbo flange distorts you can "machine" is back to flat using the flat face of a grinding wheel mounted in an angle grinder (remove the guard, wear gloves)

The bad news is I am a rubbish welder. Don't try to learn to weld on a manifold.

It has been an interesting challenge though.


Do's and don't of making a turbo manifold.

Do:
Draw up flanges in CadStd and get them made by andyw7de
Ask andy to supply a few offcuts of the same stuff to sort settings
Butt weld the pipes
Get a B&D power file and loads of belts
Get a new angle grinder because your last one broke
Think about how you are going to do all the welds
Tack it and then get someone to Tig it!


Don't
Try to learn welding on a manifold
Start welding (beyond little tacks) before finishing off all the pipes, as its difficult to get access later on.
Overlap pipes, well it seems to work, but looks rubbish
Think that welding is easy
Weld it when it isn't clamped up, as it will distort



I've still got a few holes (in the merge), but hopefully I can bodge that together. Then I can watch it all crack when I put it on the car!


Its all about the journey!


Matt

Well done Matt - they say that the best way to find out how to do something is to do it yourself. Next time around you will almost certainly do it another way but hey ho, that's experience for you I hope it all holds together for you mate

Exactly Matt, my first exhaust welding experience taught me mostly 'Donts' rather than 'Dos'. I made a full exhaust system for my old Toyota Supra from 2.5" mild steel - using a stick welder!!!! The joints ended up being strong and have lasted for years but look like they have been made using some kind of modern art experiment (ish!!). At least the welds are hidden away under the chassis.

I am about to attempt a new exhaust for my Avon and will be taking all of the advice on the above posts - cheers guys.