Coiling Tube useing the Draw Bench

by David Cruickshank on 26/01/2010

Coiling Tube useing the Drawbench

Coiling Tube using the Drawbench

Firstly you have to have access to a drawbench.

View 8 Photos at end of writing.

This is a novel way of coiling tube that an old jeweller from Hatton Garden, then the centre of the jewellery industry in  London, told me about. I still find it hard to believe although I have used it a lot over 35 years.

The silver tube I am using here is 3.85 mm diameter with a wall thickness of 0.65 mm.

The bent steel wire is 2.45 mm American ‘music wire’ or 0.096 inches. The wire should be a bit loose when the wire is inserted into the tube.

And the little coil is 1 mm copper wire which was original coiled tightly around the steel wire . It is used in the last stage to finish the withdrawal.

Now I know that this technique works for these exact measurements and proportions. The difficulty is you have to get the tempering of the steel correct. Unfortunately I cannot remember exactly what the ‘temper colour’ / quenching was. It took me 3 or 4 attempts to achieve the correct hardness. The steel either snapped or bent, wasting tube so maybe experiment with some copper tube. Or be prepared for some wastage.

You may be able to scale everything up or down a bit.

1: Buy / draw down suitable silver tube: as above. I have also used 9 ct and 18 ct gold tube. Consider the length of tube you you can buy. Say 12 inches or 300 mm.

2: Buy a length of 2.45 mm music wire or tool steel, somewhat longer than the silver tube.

3: Bend the steel wire around a suitable former. this may have to be done dull red heat, make sure there is a slight offset on the wire curve to allow the tube to coil properly. Dome end of wire.  See photo.

4: Temper and bring curved end to a high polish.

5: Grease the steel wire and melt some grease into the tube. I use ‘DRY LUBE’

6: Insert the wire into the tube. On the straight end cut off about 25 mm above the end of the tube.

7: A drawplate is reversed and the wire is loosely inserted in a hole just bigger than the wire, but too small to accept the tube.

8: The straight end protruding through the plate is gripped by the drawtongs and very gently start pulling the wire through. The  tube should start to bend against the curved end. Proceed  with caution.

When there is only a short length of straight tube left, STOP, and remove wire from drawplate, insert wire into copper coil and continue withdrawing wire.    Take care to stop as soon as the tube is all coiled and falls off the wire.         YOU MAY BREAK THE TEMPERED CURVED END OF THE WIRE!

David Cruickshank
I went to Sydney Australia in 1982 from London, previously from Aberdeen Scotland. Grays School of Art, Silversmithing and Graphic Design 1963 Since 1982 I have run a business in Terrigal supplying shops and galleries in the major cities of Australia. I produce several types of work: commissions for wedding and engagement rings, special pieces for shops. Then ranges of rings in gold and gold and titanium often layers of gold and titanium rivited together,the rivits being a feature. I have made series of pendants and brooches in silver, containing large semi- precious stones and 24 wearable pieces influenced by several visits to Morocco. I have a well equiped workshop, and am still working at 70.
David Cruickshank

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{ 22 comments… read them below or add one }

Michele Wyckoff Smith February 16, 2015 at 9:33 am

Any chance you could do a Youtube video of this? It would be great!

Richard February 6, 2015 at 5:58 am

What a great trick for bending tubing . I tried to find the ‘DRY LUBE’ in a grease form. Found a product called dry lube but it was a liquid for lubricating bicycle parts. Wonder if you could list a brand name and where to find the product you used. I have also tried thin metal cable inserted into silver tubing but have not achieved the radius that you appear to have come up with. Wow!!
Thanks for keeping old techniques alive and well and for sharing them.
Richard

Karen December 15, 2013 at 6:36 pm

We absolutely love your blog and find a lot of your post’s to be precisely what I’m looking
for. Would you offer guest writers to write content for yourself?
I wouldn’t mind creating a post or elaborating on some of the
subjects you write with regards to here. Again, awesome site!

Chris Maron May 28, 2012 at 12:25 pm

Thats awesome…hi there and to your wife also…still making that potato cod casserole 🙂
How are you?

Charles Pinckney May 1, 2012 at 3:39 am

This is sooooooooo clever! I know you said that you were not the originator of this. I’m going to call it the “Cruickshank curve” though anyway. Thank you!

pallavi gandhi December 7, 2010 at 1:59 am

superb!! thankyou!

Aaron Willoughby November 5, 2010 at 6:15 pm

Thank You again! OMG! It was like magic! The tube is still so round and with such minimal waste!

Aaron Willoughby October 29, 2010 at 6:46 pm

Oh hell yes. Thank you!!!

Bob Claborne October 29, 2010 at 10:23 am

Well Done. Here is a simple trick for hardening steel…
Heat the hook of your wire until a magnet will not stick to the red hot metal (that’s how you know when it’s hot enough). Quench it in any kind of light oil. Now it’s hard but brittle. Put the wire in your kitchen oven at 400 for one hour then turn off the power and let cool to room temp. Now your steel is hardened and tempered.

Joris October 24, 2010 at 3:40 pm

Thanks so much for this excellent tip! Wow…
Joris

Jeff Demand February 9, 2010 at 12:51 pm

Who says there isn’t any magic left. Neat neat trick.

jeffD

Lois Martens January 28, 2010 at 3:52 pm

I have responded on the forum asking what you are making with these hollow tube rings? I have printed the instructions and will be taking them in to my colleagues in the center of Rome tomorrow. For me it is great fun to see this technique and I know that one of my colleagues will enjoy this information very much. Thanks.

Sandra Gilbert January 28, 2010 at 8:07 am

That is good! I don’t see any reason it wouldn’t work for other sizes of tube/wire. Wonderful tip! Thanks!

jason January 28, 2010 at 12:06 am

That is incredibly awesome!

Does it work with square section wire and tubing as well?

Jason

Bob Edwards January 27, 2010 at 11:28 pm

Clever “twist” on die forming — never seen that one before. Thanks for sharing.

Regards,

Bob

Violaine January 27, 2010 at 6:18 pm

Brilliant! Thanks for sharing!
Best from France, Vio

hansmeevis January 27, 2010 at 9:46 am

Brilliant David. I love leaning a new bench trick, and this one is excellent. I would have NEVER figured this one out myself.
Cheers, Hans

Jim Newton January 27, 2010 at 7:19 am

I can see how this would work very well. Thanks for sharing it!

Niels Løvschal January 27, 2010 at 2:48 am

Thanks David,
A marvellous bench tip. Yes, there is still a lot to be learned from the old masters of the trade. Thanks for sharing.
Niels

Michael Sabo January 27, 2010 at 1:19 am

Woof…that is one of those “gotta see it to believe it…” things. If any one is looking for piano wire, check out the yellow pages for piano shops, tuning, restoration, refinishing and the like… for little or nothing you got tons of material. I am the proud owner of a set of strings of a vintage 1926 Steinway!

Jamie King January 27, 2010 at 12:07 am

David,
Thanks so much for taking the time to share this blog. Very interesting.
Jamie

mike edwards January 26, 2010 at 5:17 am

Wow,
That is one slick bench trick! Can you tell me if there is proportional relationship between the radius of the desired coil and the relative sizes of the tubing and insert wire used? Will this work with seamed tubing as well? If so where should the seam be positioned relative to the curved mandrel(inside of curve, outside of curve or perhaps on top so it ends up between coils)?
you’ve tantalized me! thanks so much!
Mike

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