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Tube expanders

PostPosted: Fri Mar 31, 2017 10:23 pm
by Aushy
How do you use a tube expander like the one pictured below? Do you just stick it in and away you go, or do you need to heat the copper first?

Image

Re: Tube expanders

PostPosted: Fri Mar 31, 2017 10:35 pm
by woodduck
Definitely anneal first or you'll either split the tube or worse break the tool.

Re: Tube expanders

PostPosted: Fri Mar 31, 2017 11:16 pm
by Azza76
Anneal it first mate definitely then put it in and tighten it up and wallah expanded pipe :handgestures-thumbupleft:

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 8:42 am
by Flowerpot
How would these go expanding stainless pipe?

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 8:51 am
by woodduck
Not well

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 8:52 am
by scythe
By either using really thin stainless pipe or heating it red hot with a big burner (minimum of 50mm LPG torch) while using the tube expander and trying not to burn your self.

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 9:26 am
by Flowerpot
Poo. Is it mainly the amount of force required or does the pipe want to split?

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 10:00 am
by Azza76
Flowerpot wrote:How would these go expanding stainless pipe?


We did some stainless at work not sure how thick it was though.

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 11:08 am
by woodduck
It might do it but they are made for annealed copper which is slightly softer than high tensile stainless :-B
I say if their yours and you don't mind breaking them, go for it. If their someone else's and you haven't checked the price of them for replacement, I wouldn't.

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 12:36 pm
by Flowerpot
yeah sorry, not those exact expanders. I've got some 102mm about 2mm wall stainless pipe I want to expand. I also have a 110mm diameter chunk of steel I can turn into an expander. But I'm toying with if I can just use a thread to pull it together or if I'll have to use a press. Using a press would be a pita to set up and all would be pointless if its just going to split.

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 5:54 pm
by Aushy
So I basically just heat the end of a pipe until it glows red hot, then after it's cooled use the expander?

After I solder on the ferrule do I need to do anything to harden it up again or is it fine leaving it in the annealed state? No structural integrity issues?

Re: Tube expanders

PostPosted: Sun Apr 02, 2017 9:01 pm
by woodduck
Sorry mate I got the wrong end of the stick there, yes stainless can be expanded with heat and a die and there probably is a proper tool for it. I think becasue it is hard it would more than likely split without being heated. Just remember stainless needs a fair bit of heat and constant moving of the heat sauce because it's not a great conductor and will need a clean up after. It will glow red when hot enough to bend/expand.

Once copper is annealed it can only be re hardened by work hardening, hitting with a hammer, some say wire brushing. Annealing will leave it softer and venerable to denting and bending but it doesn't seem to cause any problems with stills that of heard of, well except one bloke I remember dropping his freshly made rc once, didn't end well. Another side note is that annealed copper is harder to cut because it's soft and can grip grinding wheels and saws. Also pipe cutters don't seem to work aswell after either.

Re: Tube expanders

PostPosted: Mon Apr 03, 2017 10:29 am
by scythe
You will need to keep the stainless red hot while you are expanding it.
It will "re-harden" when it cools.
A press will be a better idea i think, using a strong back is too much like hard work.

Re: Tube expanders

PostPosted: Mon Apr 03, 2017 12:39 pm
by mattcoffs
scythe wrote:You will need to keep the stainless red hot while you are expanding it.
It will "re-harden" when it cools.
A press will be a better idea i think, using a strong back is too much like hard work.


Best check what material the expander's made of first.

Re: Tube expanders

PostPosted: Thu Dec 06, 2018 6:51 am
by spiltdrink
Old thread, I know, but just wanted throw in my 2c

About 15 years ago I used the same pipe expander as pictured by the OP. The outer is made of aluminium, older ones were of steel.
Used an aluminium one,had to taper the shoulder of the expander so it would fit inside the pipe to begin with, the Boss didn't want to spend more money on tools ( not in the budget)
Stainless pipe approx 103mm OD - 99.9mm ID . Sleeved two pieces of the same size together, probably did about 90 of them.
Hit the pipe with Oxy and stretch away. In short, it was the wrong tool for the job.
It was a complete dog to use and really hard on the expander, required ridiculous amounts of torque and the results were inconsistent.
I would not recommend going down this road.
Pay someone else to expand your pipe for you and save the $300 pipe expander for the job it was designed for.

Re: Tube expanders

PostPosted: Thu Dec 06, 2018 6:46 pm
by Ravvin
Just a quick note on your mention of annealing copper. You asked if you heat it up and just let it cool.
No, that will do the exact opposite to what you want. Copper and copper based alloys work very differently to iron based metals.
To soften (anneal) copper, you heat it up and cool it quickly. Stick it in water if you can.
This is how ammo reloaders anneal case necks on brass cases to reduce the chance of splitting them when resizing them.
Most of you will likely know this, but I thought I should mention it seeing as the question above was unanswered and might mislead newbies looking for tips.

Greg.