Exhaust expanders

[Leetig]

Hi folks. Does anyone know will those cheap expander tools work on 300 stainless? I've a feeling that they won't but don't want to find out the hard way! Thanks.

 

[chevy2]

They dont expand mild steel let alone stainless,
they're only any good for correcting out of round tubing not actually expanding.

 

[Leetig]

That's what I thought!!
Thanks

 

[dan.taylor.1]

We had a set in a garage I worked at, provided you heat the pipe they worked great. They did have metal spring retainers not o-rings though like the cheap ones

 

[Leetig]

Don't want to heat stainless to be honest. Anyone know of an affordable way to do it?

 

[Paul G]

Make a former and push it into the pipe with a 12 tonne bottle jack.

They don't like it up 'em.

 

[ibrooks]

Make a former and push it into the pipe with a 12 tonne bottle jack.

They don't like it up 'em.

The trick there is holding the pipe still whilst the former goes in and then retrieving the former afterwards.

 

[Paul G]

Strangely enough it will expand more than the former o.d.

The very first one I made I turned to 50.9mm thinking that 50.8 (2") would slip inside.

It was like a turd in a pee pot. ( techy term )

 

[Leetig]

Strangely enough it will expand more than the former o.d.

The very first one I made I turned to 50.9mm thinking that 50.8 (2") would slip inside.

It was like a turd in a pee pot. ( techy term )

Any pics of the former? Only problem is how to expand the end of a mandrel bend!

 

[dannyp]

going to say i tooka punt on a neilsen one ........ it ate itself first attempt on mild. have got a plan to use bits from it allong with a small hydralic ram to pull a wedge through the formers to see what happens, but money is on it ether chewing itself or some other failure

 

[Tigman]

Cant you cut a bit of sheet and bend that around the tube and weld on ie ( make a socket )

 

[Paul G]

Any pics of the former?

If you go down this route don't forget to coat the former in grease, then drop it on the floor.
That's what I always seem to do anyway.

Paul G

 

[Badger1bear]

They dont expand mild steel let alone stainless,
they're only any good for correcting out of round tubing not actually expanding.

100% agreed

 

[outofthefire]

Why don't you want to use heat, steel always moves better with heat, stretching it cold will work harden it making it more likely to crack at a later date

 

[Leetig]

Thanks for the pic paul. What steel did you machine them out of?

 

[Leetig]

Why don't you want to use heat, steel always moves better with heat, stretching it cold will work harden it making it more likely to crack at a later date

Don't like the idea of heating stainless plus I don't have a torch so can't do it anyway!

 

[Pete.]

What's the big deal with heating stainless?

Anyway, any time I need to make a slip-joint and have no access to a swager I cut a short piece of the original tube then slit it length-wise with a 1mm disc, wrap it round the tube it's going to slip over, secure with a jubilee clip and measure the end gap. Cut another piece to fit in this gap and weld it in.

 

[Wallace]

I used my cheap set of exhaust expanders on some alloy tube today to get a good fit up before welding, worked well.

 

[Paul G]

Thanks for the pic paul. What steel did you machine them out of?

AOBOSTIGLA

( any old bit of s???? that I've got laying about )