Tube bending

[Ghoste]

Any tips for tube bending and keeping kinks out?  Working with 3/8 steel tube and I want some nicely rounded and even 90 degree bends.

[mopar_nut_440_6]

I am by no means a pro at this but having a good quality bender with the degrees on it will make things a lot better. Less expensive benders tend to deflect a lot when trying to bend 3/8 line. I once bought a KD bender but it did not do a great job. You will also want to do some test bends so that when you are bending your longer runs you will know where to start and finish.

[Ghoste]

I have a good quality bender but I was hoping that there is some kind of insert or, I don't know- a poor mans mandrel of some type, that would make kink free bends at home.

[Tilar]

I have a pretty good bender, but something i've done in the past is take something like a pipe, maybe an extension or something the same diameter as the bend I want.  Clamp the the pipe or extension or whatever you choose in a vice and then using your hands bend the brake line. You can also use the vice to hold the one end of the line if your trying to bend close to the end.  You do have to be careful to not flatten out the line but I have pretty good luck with them not kinking.

[mikepmcs]

pack the line with sand before you bend it.

[Musicman]

It has to be a very very fine sand however

Pure lead works best, but that's a NO-NO these days

[Ghoste]

Would that decorative sand that comes in the different colors be fine enough?  Like the stuff they sell in the arts and crafts stores for filling little bottles?

[Musicman]

Only one way to find out 

[Chatt69chgr]

I packed a steel tube with table salt, crimped the ends over and then bent it 90 degrees.  Made a perfect very tight bend.  then cut off the crimped ends and washed the salt out with hot water and blow dry with compressor.  I didn't want to have to worry about any sand being left in the tube for any reason what-so-ever.  this was a piece of steel line a little bigger than brake line.

[B5charger]

I found that whenever I'm bending a line I do it twice.  The first is a practice to make sure all the bends are at the right length.  It also lets me know how far I can bend a tight turn before it crimps.  It's a pain, but the second line always comes out right.

[John_Kunkel]

Pure lead works best, but that's a NO-NO these days

There used to be a product called Benzalloy (sp?) for tube bending, it resembled lead in appearance but melted in hot water.

Some joker in our tool 'n die shop made a mold to cast a teaspoon out of Benzalloy, every time a newbie would come to work in our shop they would place the Benzalloy spoon in the sugar bowl on the coffee table.....you can guess the rest.     (damn, that coffee's strong)

[hemigeno]

Pure lead works best, but that's a NO-NO these days

There used to be a product called Benzalloy (sp?) for tube bending, it resembled lead in appearance but melted in hot water.

Some joker in our tool 'n die shop made a mold to cast a teaspoon out of Benzalloy, every time a newbie would come to work in our shop they would place the Benzalloy spoon in the sugar bowl on the coffee table.....you can guess the rest.     (damn, that coffee's strong)

Now that's pretty funny 

Of course, the joker wasn't you...   was it?   

[Musicman]

The problem with low melting point alloys and small tubing's is that the tubing must be immersed in a hot water bath when filling the tube, or the alloy will solidify on contact. Normally, you would fill the tube hot, and then dunk it in a cold water bath.
As John said, it's pretty cool stuff... but I'm not sure that you can just buy it off the street these days. It's been 20 years since I've worked with it myself.

[bull]

If your bends aren't too tight you can do it by hand if you're patient.

[Ghoste]

It's a 3/8 tube that I need to fit a pretty specific location.  I'm afraid bending it by hand may not be a solution in this case.

[b5blue]

I've got an Eastwood cat. with a bunch of bender tools in it check them out on line, also I one I picked up somewhere that has a nylon cradle on it that the tube nests in and it keeps the tube round as you crank on a bolt that makes the bend between 2 rollers. It works well but not if you need a bend close to an end or another bend.

[bull]

How tight does your corner need to be? You can always use a tin can or a socket to bend it around by hand. That way the inner part of the corner will be supported and won't kink. Is your corner any tighter than those in the pic I posted above? I did all those bends freehand. Don't be a pansy, just do it!

[Ghoste]

Pansy?  You should see all the scraps of bent tubing in my trash from "just doing it".    That's why I'm looking for a better way.
It has to be pretty tight, I'm cobbling together some fuel lines for an oddball thing.  I'm going to go with the sand packing method since the piece is only a few inches long but I have a couple of other projects I need to complete first.

[471_Magnum]

I bend 3/8" all the time for fuel lines with a tubing bender. That will get you about 1.5" radius. It won't kink.



Aluminum is the way to go though for easiest workability. Much easier to do a double flare.

[Ghoste]

That's one of the bender's I use and it's the one I use primarily.  Unfortunately I have to use steel tubing in this instance.

[471_Magnum]

Unless you're bending some really thin wall stuff (which I've never run across), that bender should work fine for 3/8" steel.

Flaring, on the other hand, will be a challenge. I wear out flaring vices in a hurry with the steel tube. One of these days I'm going to have to buck-up for a really good quality (read "expensive") flaring kit. I just use aluminum whenever possible.

[Ghoste]

The kinks in the several now scrap pieces I've tried so far defy that.

[471_Magnum]

That's really odd. Where are you getting your tubing? Are you using brake line tube?

Only time I have ever kinked a tube was when I put 5/16" tube in the 3/8" groove.

[bull]

Send it to me. I'll do it for you with my soup can.

[Ghoste]

If I had the diameter of a soup can to work with that would be great.  I need a much smaller radius Bull (which is why it kinks on the inside of the curve thus negating the use of a socket or can or whatever), but I do appreciate the offer my friend.