21 replies to this topic

[Northernpower]

For bending you ideally need something like an old-fashioned plumber's bending spring. (The suggested flex drive for a drill might be a good approximation.) I think that they are available for microbore pipe, possibly 6, 8 or 10mm. Try a plumber's supplier.

The problem with the bending spring for the small bore pipes is it fits on the outside of the pipe. If there is a flare on the pipe or a fitting it won't slide over. Its only when you get to 15mm it fits on the inside.

[tiger99]

Well, I have seen the external springs, but using an external spring should not be fundamental, so it is possible that someone, somewhere makes a suitable internal spring. However, assuming that you can't find one, because no-one does make them, the other way is to fill the tube with low melting point metal, and heat it afterwards to drain it out. You can get a special alloy for doing it, and unlike when soldering, you do not apply flux, because you really do not want it to stick.

 

Or do the same with some kind of plastic. Not one that is smelly, sticky or toxic when heated, so absolutely no PTFE (MAJOR HAZARD) or PVC. A close fitting length of polyethylene rod should do the trick. A heat gun will remove it, but watch out for drips on your skin (it sticks and burns seriously, where the likes of solder tends to run off) and it may ignite if you over-do the heat. You can also use tightly packed dry sand, but you would want to do a superb cleaning job afterwards for obvious reasons.

 

These sort of tricks are done by modellers and such like, and I hope that one of them will work for your wiper tube. Please let us know how it goes.

Edited by tiger99, 18 May 2017 - 09:05 PM.

[Turbo Nick]

Just mounted mine inside the car, bought a longer drive cable and a new piece of bundy tube from car builder solutions. Bent the tube gently by hand and it's fine, just keep the bends very slight and you should be grand.

[HUBBA.HUBBA]

I've never seen a small bore bending spring. Small bore annealed copper doesn't need it. Think I'll use a normal pipe bender for steel pipe with the right size former should keep it true inside. I'll have the bend as far away from the motor as poss to get the least angle possible

[Stu1961]

At work we use a small former or slightly dampened sand for bending small tubes such as 4,8 and 10mm bundy, the sand method works well. Plug one end of the tube with tissue then with the end of the tube on a solid surface ram the sand into the tube then plug the other end likewise. To remove the sand just soak in water tissue falls out followed by the sand. This method works well on any tube were there is a risk of the tube collapsing or becoming kinked.    

[Northernpower]

I've never seen a small bore bending spring. Small bore annealed copper doesn't need it. Think I'll use a normal pipe bender for steel pipe with the right size former should keep it true inside. I'll have the bend as far away from the motor as poss to get the least angle possible

It depends what you're calling small bore. I use an 8mm and 10mm spring but they're both external.

[HUBBA.HUBBA]

I've never seen a small bore bending spring. Small bore annealed copper doesn't need it. Think I'll use a normal pipe bender for steel pipe with the right size former should keep it true inside. I'll have the bend as far away from the motor as poss to get the least angle possible

It depends what you're calling small bore. I use an 8mm and 10mm spring but they're both external.

Yep, I'm talking about internal