mjollnir

Hi,

I'm practicing my tube bending skills.

With 3/8 and 5/16 lines and my 10$ chinese bender, here are the poor results:





Some bends are not cracked, but all of them are pinched and probably reduce the flow a lot. I wonder if I can achieve better results with this bender?

I tried oil on surface of tube to ease the bending process. Maybe heating the tube a bit? Any tricks?

ZFreie

How fast are you making the bends? Should be a slow fluid motion so you don't kink it.

mjollnir

I tried slowly as well, sometimes it's not kinked but then the section of the tube at the bend is not circular, more like a fat potatoe

HexenLord

Are you using a bender that has a channel for 3/8" tubing?

Also, it looks like your tubing is sliding in the bender. Grab a pair of vice grips and clamp the end of the tubing into the bender so that it doesn't slide around the bend. If it slides, it will crimp from excess length in the bend.

mjollnir

yes it's for 3/8 as well

good point about sliding, it's better but not yet a good nice bend

01ssreda4

iTrader: (96)

You're doing something wrong. I bought a 5 dollar tool and bent my first brake lines ever and they turned out fantastic. The inside of the bend must be supported with the proper die to keep the bend from kinking.

01ssreda4

iTrader: (96)

I hope you aren't bending like you have it positioned in the picture because its not right.

mjollnir

How would you set it up?

BOXCHEV

iTrader: (3)

Fill line with fine play sand, then bend.

Blown06

iTrader: (32)

Whatever you do.......don't do this.

Filling the sand is not needed to make a good line.
If you put sand in it and don't get it all out your gonna have major issues. Not worth the risk since it is not needed.

BOXCHEV

iTrader: (3)

I used to kink lines with a POS bender like that, fill the line with sand, bend and dump it out. Compressed air few times, maybe lil water gets all the sand out no problem.

mjollnir

Last bends, better!

https://i.imgur.com/k5q6FRx.jpg

Blown06

iTrader: (32)

Guys.......

If you can't make a good bend without sand, get a good bender or let someone else do it.

I'm not bashing......I'm trying to save ya'll a bunch of future head and wallet aches.

subarubill96

iTrader: (9)

slow fluid motion like mentioned before, plus you gotta make sure the tubing is more secure, i can see it slipping in the die when your making the bend. It seems like you might be bending too far, you don't want the throat of the bend kinking or crimping at all.
practice makes perfect. i can do that stuff in my sleep now but we all had crappy bends when we first started out. also what material are you bending? looks like steel, different materials bend differently. i started doing copper when i did mostly refrigeration stuff so everything else was much more forgiving in my opinion, ie not so soft so you kink it instantly.keep at it, youll be a pro in no time.

mjollnir

you're right i'm getting better with practice

it's 304 stainless steel welded, and I think the radius is a bit small for my cheap tool, i have better bends by slightly increasing the radius

still have to buy a good tool for 1/2 inch OD, any brand to recommend?

subarubill96

iTrader: (9)

that explains it. ss is much harder to bend, i have a eastwood cheapie i use at home that works great. i use an old imperial at work. try to get some mild steel brake line and see how that bends up compared to the ss you have.

mjollnir

some updates here

I can do almost perfect bends with my 10$ multisize chinese tool which I use for 3/8 and 5/16 SS 304 grade

Now, trying to bend 1/2" OD SS 304 grade 0.02" thick with one of the best tool on the market, RIDGID 400 series.
http://www.ridgid.com/us/en/400-seri...rument-benders

And my bends are awful, as subarubill96 said my tube is moving when i'm reaching about 60° thus creating a bend if I continue to 90°. I tried securing it with tube clips, vise clamp or my ridgid flare tool but still my bend is ugly. I tried lubricating the pad moving on my tube to help.

Here are some pictures:

Blown06

iTrader: (32)

Is there any more you could do to help the tube "get pulled through" the bender?

mjollnir

tried vise clamp, 1/2inch flare tool, tube clips..

mjollnir

here's the "best" 90° bend i could do, by increasing the radius to 3" instead of 1.5" as supported by tool. i did this by several pass of 10°, moving the tube each pass



and 45° bends with 1.5" radius




some people suggested that 0.02" is too thin to be bend. what do you think?