evenly twistin large pieces...

[Aaron J. Cergol]

Hi all,

I'm looking for any suggestions on how to twist longer stock pieces uniformly. I can twist 1/2" and slightly larger cold, but I'm looking to twist a 8-10' section of 1"-1 1/2" thick square for a railing. I obviously cannot heat this much op in a forge, so how is it done? I have seen motorized twisting apparatuses but I do not have the time, or the means to make one now.

Now, I recall visiting a blacksmith years ago when I was just a wee lad, and he had me twist some very large square stock COLD, simply by continuously turning a small crank. he also hooked this up to a basic cordless drill too...anyone have ideas or plans for one of these? I recall it was about 4 or more turns to get one 360 degree twist of the bar. I am not a fan of motorized twisters as I liked the control of a hand one, so this may be the route to go.

Thanks,

Aaron

[doc]

Find an old winch from a truck or some other type of gear reducer. These can be set up with a hand crank or drill motor to operate. The minimum reduction for 1" stock twisting by hand or with a small motor with this method would be at least 75 to 1

Doc

[John B]

Hi all,

I'm looking for any suggestions on how to twist longer stock pieces uniformly. I can twist 1/2" and slightly larger cold, but I'm looking to twist a 8-10' section of 1"-1 1/2" thick square for a railing. I obviously cannot heat this much op in a forge, so how is it done? Thanks,

Aaron

Where do you get the idea you cannot heat that length or section in a forge?

This length can be easily done in either a gas forge, or coke/coal, you may need to alter the configuration of your fire or forge, or even make a 'temporary' new forge

I have heated up to 32" long in a temporary gas forge made by placing refrectory bricks to make an open fronted tunnel with end access to poke the bars through, I directed three burners through the front aperture of the tunnel and had no trouble getting bars that size/volume up to heat

Alternatively a coke forge can be easily made from a pipe with one end blanked off, and holes in a line down one side to allow air through, this is your tue iron, you can use this in a ditch dug in the ground, or just weld a couple of plates on in a vee form , weld on ends and supports for legs to make it stable, stick your blower on or near to the pipe so you can adjust the air flow and you are ready to go

[Francis Trez Cole]

I would agree with John B I have dug a trench in the ground filed it with charcoal and heated 6 pieces of 3/8" round rod 6' long to make a rope. I covered the top with sheet metal and used a blower fron the end it worked great.

[dablacksmith]

any cold twisting on that size bar is going to require a LOT of torque .. ide find a way to heat and still your going to need leverage .. your twists also look much better when you heat them as you can get them much tighter. good luck!

[MRobb]

Very interested in the outcome. Please post pics of the process.


Mitch

[ThomasPowers]

Stock twists tightest where it's cross section is smallest or where it's hottest---why cold twisting of stock is usually more even than hot as both factors are stable. (and why you can get an even twist on a tapered piece by "working" the heat in it.)

One way to do an even twist with a small forge is to heat a section, twist it, heat the next section twist it, etc---cooling the previous twisted sections as needed. Experience helps to get an even seamless twist using this method.

Some folks will use this method with a rosebud torch so they are heating as they go along.

Trench forges are fairly easy to make and "dirt" cheap. (but you have to watch out for un-even heating---a squirt bottle can help out if a hot section wants to overtwist---cool it!

Note that cold twisting can store a LOT of energy in the system and failure modes of the piece or the equipment can be exciting and dangerous. Be sure that you can back off the pressure before removing the piece from the equipment.

[Frank Turley]

If you do it section by section with localized quenching, it is time consuming, but in a small shop, it might be the route to go. That is heavy stock and you'll need helper-stands plus a good vise for that type of work. The piece will be in the vise horizontally. Even with a bright heat and a large twisting wrench, you're going to use muscles you didn't know you had. Two men on the equilateral handled wrench really helps. Try to straighten any bends as you go using a wooden stump or a plank on the anvil and a large wooden or rawhide mallet.

For those who think this is going to be easy, I would like to see you evenly twist a 10 foot length of 1.5" square. I laugh.

http://www.turleyforge.com Granddaddy of Blacksmith Schools

[Rich Hale]

On one of the biker build off shows a while back,, Indian Larry,,( R.I.P.) Twisted a front down tube for a bike and used about that size stock. He welded one end of it to a large heavy work bench and heated it with a LArge rosebud.. then a couple of guys twisted. They did not show it all but my guess is everyone took turns on the wrrenches and it used everyone up. They did tighter twists than you mentioned but at the end it looked great....

[Dragons lair]

Best way for long even twists is with a torch. I have both coal and gasser. That said any long twists are done with my cutting torch. Have a holder for it. Can use it for forging at a high cost.
Ken.

[John B]

If you do it section by section with localized quenching, it is time consuming, but in a small shop, it might be the route to go. That is heavy stock and you'll need helper-stands plus a good vise for that type of work. The piece will be in the vise horizontally. Even with a bright heat and a large twisting wrench, you're going to use muscles you didn't know you had. Two men on the equilateral handled wrench really helps. Try to straighten any bends as you go using a wooden stump or a plank on the anvil and a large wooden or rawhide mallet.

For those who think this is going to be easy, I would like to see you evenly twist a 10 foot length of 1.5" square. I laugh.

http://www.turleyforge.com Granddaddy of Blacksmith Schools

Sorry to take exception, I am sure you would get entertainment from watching someone struggle, and I am also reasonably sure you would step in with some assistance if you thought they warranted it.

As you know, blacksmithing is easy when you figure it out, after all you can only heat a section and do one thing at a time on that piece/area then build on that, its the sequence of work that makes the piece look complicated.

Having done something similar using the forge I described I don't see much to amuse, it is a straight forward basic twist and the techniques used to produce an even twist on a small section bar are valid on a larger one,

The biggest problem is in the handling of it because of its physical size,

By positioning the forge and using suitable supports over the bars length the bar can be gradually twisted along its length and adjusted as you go by using calipers to check the pitches

In this situation it is easier to secure one end of the bar, and move the forge along the length of an overlong bar which can be cut to length after twisting if required.

By supporting it at strategic places along its length it will remain relatively straight.

If this job is a one off then this method works. (It is after all only like using a rosebud, but with a broader heatband)

[Bryce Masuk]

If you just want a basic twist the whole length of the bar it would be easier just to buy a pre twisted bar or have someone put it in a lathe and twist it for you.

this is the most consistant method if it needs to look near perfect its the only way to do it never compete with a machine to arrive at the same place you will never win that battle.


if your making something handmade make it nicer than a machine can make it

personally I would do it by hand and heat up as much as possible in the forge and twist it one way x amount of twists so it looks nice and then space it about 3 inches a part and do the same the other way and repeat so it has a pretty consistant pattern.

you cant just go buy that up from a supplier if you just want a basic twisted bar
http://www.twistedbars.com/products/TwistedBars.aspx

[Frosty]

The easiest way to hand twist something this scale evenly is to hang it vertically and use a heavy large diameter wheel on the bottom for a wrench. The longer the bar the easier it is to twist and keep even. Hanging a few hundred lbs. on the bottom will make it just plain easy to keep straight and once you get the mass moving it's easy to keep moving.

Frosty the Lucky.

[Marcus Hopfinger]

My father-in-law was telling me about an old metal worker he knew that would put long pieces he was twisting in a pipe that was just a touch bigger than the stock he was twisting to keep the piece straight.