# tube bending with fusible alloys



## mchimonas (Dec 19, 2008)

In the Paterek Manual Mr. Paterek states you can bend chain stays and seat stays but filling the tubes with a fusible alloy (one that melts below h2o boiling temp) and putting it in a vice and simply applying force. He says this won't crimp the tube. Anyone ever do this before? It seems so simple compared to getting a proper tube bender without the dies.


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## pvd (Jan 4, 2006)

I've been wanting to do it.

http://en.wikipedia.org/wiki/Bismuth


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## Live Wire (Aug 27, 2007)

I've been thinking about it, but the nasty stuff in Cerrobend (Lead, Cadmium) has put me off. 
Gonna make a bender w/rollers this winter.


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## mchimonas (Dec 19, 2008)

I hear you can find some stuff without lead and cadmium.


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## vulture (Jan 13, 2004)

*ice ice baby*

You can fill the tubes with water, freeze, bend, melt. You only need to cap one end and freeze the tube upright slightly. Water expands when frozen remember. Be sure not to get steel chips on your frozen burritos.


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## mchimonas (Dec 19, 2008)

Have you tried that. Seems so cheap and easy. Does it work?


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## pvd (Jan 4, 2006)

I've done ice. It's really tricky and you have to work quick. Sometime things go wrong even when you try hard to get it just right. You can't do just anything with it, but it does help on some small stuff.


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## mchimonas (Dec 19, 2008)

Can you do Chain stays with it? Seems like the ice would crack instead of bend so you run the risk of crimping the tube.... there again I have no experience doing this sort of thing.


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## pvd (Jan 4, 2006)

That's what I use it for.


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## CheeseSoda (Jan 8, 2007)

Ice is how they get the crazy 180deg 2" radius bends in trombone/trumpet/etc tubes. As best as I know, they just freeze those solid with one end open, but it's also in brass and they may use some kind of additives... Are there any horn-makers on here?


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## DWF (Jan 12, 2004)

If you use cerrobend or other low temp alloys, you need to make sure you get it all out, every molecule of it, before you start your joinery. Nasty, nasty, stuff in there if you get to start off gassing. It's also very expensive.


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## dbohemian (Mar 25, 2007)

Don is correct as usual.

People get all worried about lead and cadmium. As long as they are locked up in an alloy you are perfectly safe. Treat the stuff with respect, don't go burning it or munching on it or sleeping with it and you will be fine.

Dave Bohm
Bohemian


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## Schmucker (Aug 23, 2007)

Like Isaac Newton said, a spoonful of Mercury a day keeps the doctor away!


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## rustola (Jan 15, 2008)

I've heard of (but not done myself) coating the inside of the tube with some kind of oil before pouring in the cerrobend. Apparently helps in the removal process...


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## mchimonas (Dec 19, 2008)

Hey Wade... just saw the maroon bike and I think the design is oh so clever. I was wondering if I could mimic that design for my own use and for friends (no money being made). I only know how to braze, but your design would actually work with lugs (put the ST-TT and TT-HT lugs upside down).

Marc


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## 18bikes (Jan 15, 2007)

has anyone had any experience with this stuff

http://www.bendalloy.co.uk/page9.html

or something similar?

matt


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## vulture (Jan 13, 2004)

*inspired by mantis*



mchimonas said:


> Hey Wade... just saw the maroon bike and I think the design is oh so clever. I was wondering if I could mimic that design for my own use and for friends (no money being made). I only know how to braze, but your design would actually work with lugs (put the ST-TT and TT-HT lugs upside down).
> 
> Marc


Marc, that frame is full tribute to late 80s mantis valkyrie. Those old mantises were fillet brazed but I tigged mine. I like to build frames that are inspired by old designs, bikes I wanted back in the day but couldn't have for one reason or another. Credit where credit is due.


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## Peter E (Feb 16, 2004)

i have tried bendalloy. its possible to wrinkle 4130 even when they are filled with this stuff  
Probably my fault, trying to bend it with a home made press with too small radius
http://happymtb.org/forum/file.php/12/file=20455

the metal is very similar to led but melts at about 80 deg C. I found it to be a little bit too much trouble to work with. I will build a better tube bender and even try ice before I give bendalloy another try.

When I heated the tube to melt out the bendalloy I collected the liquid alloy in a stainless bucket. some of the alloy really stuck to the stainless steel. I hope I got all af the alloy out of my tube...


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## steadite (Jan 13, 2007)

On Discovery channel they showed how to bend brass for instruments (I think it was trumpets). They filled it with soap (dish detergent) and froze it. I think the point was that the detergent was kind of "plastic" even when frozen unlike water which would be hard.


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## Thylacine (Feb 29, 2004)

vulture said:


> ....Credit where credit is due.


Finally someone with a professional attitude towards IP.

I'd love to do some 'improved' Richard Cunningham designs. Most of them have so many engineering flaws it's not funny, but there is a definite aesthetic there that I can relate to.


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## FRRider (Feb 12, 2007)

An old hot rodders secret is to pack it with wet sand then bend it.


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## pvd (Jan 4, 2006)

steadite said:


> I think the point was that the detergent was kind of "plastic" even when frozen unlike water which would be hard.


The problem with ice is not that it is hard, but that it melts. The heat generated at the bend is enough to melt the ice very quickly. You can see this happen to the condensation as you bend. I will use ice again, but I would like to get it much much colder. At normal freezer temperature you only have time for one quick bend.

I can only imagine that the soap is acting as a lubricant of some kind. Brass and high carbon steel are very different animals. Steel is a real [email protected] in comparison.


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## dbohemian (Mar 25, 2007)

IMHO most of these issues can be solved with good bending equipment. There is bending equip that can do near perfect bends without an internal filler and most of the time you will find that someone has used some ghetto setup and gets poor results.

It all really depends on what kind of bends in what kind of material at what size and radii. Are we still talking about PVD's 2.5'' radius with 1.25 tubing? or something like that. That will take some special equip with an internal mandrel but then again that is extremely tight.

Dave Bohm
Bohemian


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## ernestrome (Aug 1, 2008)

pvd said:


> The problem with ice is not that it is hard, but that it melts. The heat generated at the bend is enough to melt the ice very quickly. You can see this happen to the condensation as you bend. I will use ice again, but I would like to get it much much colder. At normal freezer temperature you only have time for one quick bend.
> 
> I can only imagine that the soap is acting as a lubricant of some kind. Brass and high carbon steel are very different animals. Steel is a real [email protected] in comparison.


You could always use some plumber's freeze spray to cool the bend and refreeze the internal ice.


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## MichauxYeti (Nov 10, 2005)

Anyone tried using wet sand as FRRider mentioned? I've also heard of this method but never had a need to try it.


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## buildyourown (Dec 1, 2004)

The cerrobend works. If you coat the tubes with MM oil, it won't stick.
It is a pain to use. If you are only doing this once in your entire career, it is a decent solution. If you will ever do it again, just build the bender. There are some great examples on here of how to build your own ghetto bender for cheap.


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## nogod (May 30, 2009)

a simple version is to use what trumpet builders use: frozen soapy water 
the soap lubricates it plus it doesnt really freeze all the way solid. my metal shop teacher first showed me this. but you should use a bender still. but like said above a good bender works great. but the intended use of a filler inside the tube is for 180 degree bends. something that would crumble bike tubing for sure.


"ooops i just read all the threads sorry this has already been said"


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## Schmitty (Sep 7, 2008)

I just read an old <1900 bicycle repair book where they mention using rosin to bend tubes. Poor it in, melt it out. Sounds messy.

-Schmitty-


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## zipzit (Aug 3, 2005)

How about candle wax (paraffin)? I'd think that would have the right consistency. And when you are done, add a couple of crayons to the mix, and use the paraffin to make some nice candles? According to wiki http://en.wikipedia.org/wiki/Paraffin the stuff melts at 117 deg F to 147 deg F of so. Probably easier to work with than ice (unless you live in the Dakotas and its really cold outside.) If you need more density, mix the stuff with sand?

Anybody tried it?

Why we're kinda sorta on the topic, has anyone used alternative tubes to 'prove out' bender concepts? I'm thinking that cheap conduit be used to determine if a crinkle will occur at a critical area... Perhaps a way to compare bends with fillers ice or sand or wax / wooden 2x4 'mold' / 3 roller bender with driven wheel / bench vise and sine bar bender, etc...

zip

Oh..... and am I the only guy offended by the use of absolutely unexplained abbreviations? Yes I know you are smarter than me cause you know something that I don't but it makes it really hard to communicate. Best practice is to use 'em but define them When First Used (WFU). (please insert the 'this is a for framebuilders only forum' arguments here...)



buildyourown said:


> The cerrobend works. If you coat the tubes with MM oil, it won't stick..


Just for laughs, what is MM oil? Is that something that you get from squeezing M&M's (do you need the plain or peanut?)


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## Blaster1200 (Feb 20, 2004)

zipzit said:


> Just for laughs, what is MM oil? Is that something that you get from squeezing M&M's (do you need the plain or peanut?)


A very common type of oil around a shop is Marvel Mystery Oil. Although perhaps not common to a layperson, it is a common oil used in a shop, and so most who read this may guess this product.

On the other hand, maybe he is talking about M&M oil...


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## AlexJK (May 2, 2009)

for ice used in making trombones they mix it with basically dishsoap, the legit stuff is likely the same but without the perfumes and dyes etc.

bahh... buncha people bet me to it...


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## nogod (May 30, 2009)

Schmitty said:


> I just read an old <1900 bicycle repair book where they mention using rosin to bend tubes. Poor it in, melt it out. Sounds messy.
> 
> -Schmitty-


that sounds awsome alot better then ice. on the same note what about wax?


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## j-ro (Feb 21, 2009)

I use cerro bend in a shop outfitters bender with a 3/4 round die for my s-bends it works great, I've given thought to leaving it in while I flatten the stay in the "s" area (ala speedvagen) One note, I didnt melt enough for two stays once and filled the second stay with a two pour, thinking that it would be hot enough to remelt and blend together.
It did neither, it cracked clean in half where I made the second bend. 
I have tried to bend these stays in my bender with out filling them and they flatten and crumple, for as little as I use the cerrobend , a mask and my monster shop fan keep things pretty clean


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## coconinocycles (Sep 23, 2006)

check out this new gizmo - that's a wrinkle free bend in a piece of 1.125 x .028. i'm stoked to have all my bending in house now!!


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## nogod (May 30, 2009)

coconinocycles said:


> check out this new gizmo - that's a wrinkle free bend in a piece of 1.125 x .028. i'm stoked to have all my bending in house now!!


gratz i like those adjustable rollers:thumbsup:


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## AZ (Apr 14, 2009)

Sand will work but it must be packed in and both ends of tube sealed .


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## pvd (Jan 4, 2006)

coconinocycles said:


> check out this new gizmo - that's a wrinkle free bend in a piece of 1.125 x .028. i'm stoked to have all my bending in house now!!


Who made that bender? Where did you get it?


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## pvd (Jan 4, 2006)

Nevermind. I found it. Interesting...makes me want to do some curvy bikes.

https://vansantent.com/tube_bending_machines/pro_tools_manual_roll_bender.html


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## nogod (May 30, 2009)

wow im glad i have a lathe those 295$ roller dies are crazy!


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## shandcycles (Jan 15, 2008)

Hey Steve,

is that roller bender any good for smaller radius bends like stays?

Cheers


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## pvd (Jan 4, 2006)

nogod said:


> wow im glad i have a lathe those 295$ roller dies are crazy!


I'm sure you will find that the time, materials, and skill involved in making 3 quality rollers makes $295 pretty cheap. I'm not sweating that price.


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## coconinocycles (Sep 23, 2006)

pvd said:


> Nevermind. I found it. Interesting...makes me want to do some curvy bikes.


you would like it - turns with one hand! good for all types of wheeled vehicles.........


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## coconinocycles (Sep 23, 2006)

nogod said:


> wow im glad i have a lathe those 295$ roller dies are crazy!


i thought it was cheap! they weigh about 25lbs each. in frame building you're gonna drop cash if you wanna make cash. i'm too busy to make rollers, i have bikes to make plus, you gotta get those deductions to the taxman every year man! you can either buy tooling or give the $$$$ to the Gov and get nuthin'. once you know the rules you can use them to you favor - heck, i buy stacks of dropouts at $100+ a pop!


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## coconinocycles (Sep 23, 2006)

shandcycles said:


> Hey Steve,
> 
> is that roller bender any good for smaller radius bends like stays?
> 
> Cheers


 hey, Steven - hope you are well! you *could* do them, i reckon.......a smaller one would be better, i use an arbor press with a "shoe" and two "cradles" made by good old Vulture Cycles :thumbsup: i bet you never thought that thing would still be running, huh Wade? i've seen some great SS's bent on small radius wooden mandrels - like 8"-10". SS's don't need much. also, you can cram a SS full of brass rod for bending - works good! larger diameter SS's crimp easier then smaller diameter ones = beer can effect......19mm's are hard to bend.....bending thinwall is all about fully encapsulating {sp?} the tube....i do all my bending except CS's. don't wanna go there.......don't need to. if you really need to you can put a CS on the bench & put a curved object on it with a C-clamp & squish it slightly. did you guys ever see my ski chair? it was a bending lesson big time.........


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## nogod (May 30, 2009)

sorry guys i understand the cost is actually good. ive priced them before. but im poor and just a hobbyist. someday ill make and sell bikes. im planing on it down the road. but i need more practice before then. lol to obtain the quality you guys make i need lots of practice! and i dont mind taking the time to turn them. and i have some solid big enough laying around. besides i enjoy any excuse to use my lathe. lol its a museum piece actually. its a 1922 Star 10" x 30" flat belt drive.


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## shirk (Mar 24, 2004)

coconinocycles said:


> my ski chair? it was a bending lesson big time.........


Have any more pics of this project? Is it finished?


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## smdubovsky (Apr 27, 2007)

nogod said:


> but im poor and just a hobbyist


HF makes a $150 version. It and a couple of others were posted on my 'how to arch a ST' thread. As nice as the tricktools? No, but I've seen its results and it works.


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## Guest (Aug 28, 2009)

*jd2*

I have had great luck with the JD2 bender and SS/CS. it will shrink a bit in the bend, but most SS bends are <12 deg so the bend is usually <1 inch long. No issues so far, was fast, easy, repeatable, easy to keep in plane for multiple bends and looks good. I imagine you could use the soap / ice/ sand trick with the JD2 to get even better results. I think i used a 2.5 radius on ,035 .750 4130. I dont think i would not recommend the JD2 for bends over 20 deg. with the thin wall tube. :thumbsup:


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## smdubovsky (Apr 27, 2007)

jimfab, I also have a jd2 (for rollcages) but don't have small dies. 19mm SS = 3/4" which they make. Did you already have the 2.25" rad or did you buy it just for this? I would think a 4.5 or 5.5" rad would still be more than enough.


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## Guest (Aug 28, 2009)

*had it*

Hello , I double checked, it is a 2.25. I have had it for a long time, i used to make sway bars with it as well as allot of general purpose stuff. 3/4 is a nice size to have anyway.2.25 inch has worked well for SS/CS for me, it seems to flow nice with a 2-2.2 tire. 5 inch sounds kinda big to me, but it is your baby, give it a shot and let us know how it woks i bet it would look cool


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## coconinocycles (Sep 23, 2006)

shirk said:


> Have any more pics of this project? Is it finished?


yep! works awesome! i'm gonna skip the "bindings" and go direct-mount on the skiis this season.


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## edoz (Jan 16, 2004)

coconinocycles said:


> also, you can cram a SS full of brass rod for bending - works good! ...


I read that, ran down to the garage, grabbed a pound of c-04 rod from my pvc tube and started looking for something to bend. It worked like freakin magic on a 14mm seatstay I'd kinked trying to s-bend a few days ago. You sir, are a dang genius. Are you gonna be at SSWC by chance? I'll buy you a couple of whatever you drink for that little gem plus all the others I've swiped from you


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## coconinocycles (Sep 23, 2006)

edoz said:


> I read that, ran down to the garage, grabbed a pound of c-04 rod from my pvc tube and started looking for something to bend. It worked like freakin magic on a 14mm seatstay I'd kinked trying to s-bend a few days ago. You sir, are a dang genius. Are you gonna be at SSWC by chance? I'll buy you a couple of whatever you drink for that little gem plus all the others I've swiped from you


no worries, man! i got that from Paul Sadoff, i think. i won't be at SSWC - i' ve been to a few but there will be probally 10+ Cocos & my wife will be there on her flowery 650B. i'm rowing the Grand Canyon in Oct/Nov for 16 days & need to get bikes out before then.....:thumbsup: .... rock on, Steve.


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## side__kicker (Jan 11, 2012)

*bending tubes with fusable alloy*

You can bend tubes by first filling them with a low melt fusible alloy like DAC 117 or amalloy 117 (the 117 represents the melting temperature of the alloy) but I would still use a tube bender. The alloy just prevents the tube from kinking or weakening at the bend. Afterwards you can remove the alloy by melting it at or above the 117 degree melt temp of the alloy. there are alloys that will melt as low as 117 degrees or as high as about 251. All of them work fine for bending tubes. The alloys are expensive but I know where to get them at about half price if anyone is interested.


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## side__kicker (Jan 11, 2012)

*bending tubes with low melt alloy*

oops accidently submitted twice and don't see a delete button. You can bend tubes by first filling them with a low melt fusible alloy like DAC 117 or amalloy 117 (the 117 represents the melting temperature of the alloy) but I would still use a tube bender. The alloy just prevents the tube from kinking or weakening at the bend. Afterwards you can remove the alloy by melting it at or above the 117 degree melt temp of the alloy. there are alloys that will melt as low as 117 degrees or as high as about 251. All of them work fine for bending tubes. The alloys are expensive but I know where to get them at about half price if anyone is interested.


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