Long Tapered Twists

[Gundog48]

I've got a project coming up for which I will have a lot of time! It's a sign bracket for a brewery called the Crocodile Brewing Company. I've got a good idea on the design, but I was thinking of taking one of the bars and putting a pineapple twist along the length of it to mimic the look of a crocodile. Unfortunately, I have many problems with it which means that I likely won't be able to do it, but I was wondering if you had any alternatives.

 

The first issue would be the length- it's going to be a long bar and I've only ever been able to do twists about 8" long as that's what I can heat up at any one time with the forge. I have the equipment of my school at my disposal this time which means I have access to an OA torch, but it'll still be a challenge to heat all that up and I'll probably have to make some kind of jig to hold it square. The other, and probably biggest problem, it that I'd like to taper it to a long point. I could do that after twisting and loose my texture, or taper it before twisting- but as far as I know it's impossible to twist a long taper unless you're doing it separately from the rest of the bar.

 

Does anyone have any ideas as to how I could do this, or if it's even possible?

[VaughnT]

It's not impossible to twist a long taper.  It's very difficult to get the same rate of twists through the length, though.

 

I've never been able to do the entire length in one shot, but I've had reasonable success by doing short sections and "building up" to the length I needed.  

 

Draw your taper.  Scribe a line down the middle of the face on all four sides just like you're going to do a standard pineapple twist, but only heat/twist one small section (maybe 6"-8").  Then chuck that finished part into the vise and start on the next part.  Because the piece is tapering, one end of the hot section is going to want to twist faster and this is a bugger to try to deal with if you're trying to make a pretty/symmetrical twist.  But, for an animal's tail, you aren't looking for a perfect pineapple twist.  You want something that's organic and looks irregular or lumpy because that's how gators and crocodiles look.

 

Depending on how high the sign is going to be, you might not need that much detail because the customer's eye won't pick it up.  I've also had good luck with lightly-hammered rebar giving a very reptilian look.

[ThomasPowers]

Squirtgun---one of the big ones.  Steel will twist tighter where it is hottest or smallest in crossection.  Since you have two variables you can manage the twist by modifying one of them---the heat!

 

Heat the piece and twist---the smallest part will twist up---cool it down and keep twisting repeating as you follow it up the taper.

 

For another idea:  what about making some texturing dies from a bush hammer?

[Chinobi]

Ddnt somebody use an old farriers rasp as texturing plates to make reptilian scales a while back? I think that would be loads easier than a pineapple on a taper.

As far as the desired twist being longer than your forge, take it in sections and tweak it until they are uniform, don't try and get it all in one heat. You shouldn't need anything special to hold it either. Vise on one side and twisting wrench on the other is all you need. If it gets bendy you can straighten it out with a wooden mallet on a block of wood (see stuart's vid for what I'm referring to) to avoid mangling your twosted texture or put it in the vise lengthwise and use the vise jaws to gently squeeze it back to straight.

Edit for autocorrect...

[basher]

this is defiantly a job for a super heater nozzle. one of those pepper pot nozzles for oxy acetylene or oxy propane my preferred method

 

Draw your taper and then clamp the thick end in a vice hold the other end (thin)in a twisting wrench. start at the thick end and work down to the thin end  , that way there is enough stiffness in the colder thin end to twist the thicker material.

 forges are only one way of heating.

[Frosty]

Taper, incise first. Torch heat as you go, start the twist at the thick end work your way to the thin end. Remember to keep count. Don't worry about keeping it straight, just use a mallet on a wood block at a moderate heat to true it up.

 

Not easy but not a major pain.

 

Frosty The Lucky.

[Gundog48]

Thanks for the help everyone! I have a long time on this project so I'd really like to push the boat out and give it the best I have- I'll do some experimenting this weekend at home if the weather permits it! I'll certainly look into making a texture plate as well, I've got time to play around and get it just right!