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Bending Small tubing


#1

I have looked in the archives for on bending small tubing
but did not find anything. I am trying to make a spout for a
miniature tea pot. In trying to get the proper bend the tubing
collapses. Any suggestions will be
appreciated.


#2

Carobtree, try finding a spring coil that would fit inside the tube,
it will help keep the tubing from collapsing, and then can be removed.
Bend the tubing slowly.

Hope this works for you, it did for me.

Kelly


#3

Hi;

I heard of one method. A rubber gasket (O-ring) is being inserted and
stretched into the tubing. The diameter of the rubber gets thinner
when being stretched. When the tension is released, the rubber fits
tightly, and a piece of tubing can be bent. Burning off or dissolving
in acid would be the method to get rid of the inserted rubber.

Good luck
Michaela


#4
I have looked in the archives for on bending small tubing
but did not find anything.  I am trying to make a spout for a
miniature tea pot. In trying to get the proper bend the tubing
collapses. Any suggestions will be
appreciated.

I believe that there are postings in the archives on this, however I
have had luck with a set of small tubing benders I purchased from
Micro Mark for a few dollars. They are not hard to use and work
adequately. I just saw in Harbor Freight catalog a tubing bender
mechanism for under $15 that looks interesting. Since they are
offering free shipping until March 31, I think I will get one and try
it. I will make my attempts known!

Good Luck,

Suzanne


#5

Many hardware stores sell tube benders which are just tightly coiled,
flexible steel tubes that are meant to be slipped over the annealed
tubing and then bent by hand. It doesn’t allow for a tight bend but is
helpful for a nice gradual curve. I’ve tried filling the tubing with
melted wax and after hardening, it curves quite well without
collapsing. Pliers are a bit harsh to use; if you have a long enough
piece to handle, bending it over a dowel or something works best. I’ve
also heard of plugging one end and filling the tubing with fine sand,
plugging the other end and then bending. Also doing the same with
water and freezing it to give support to the tubing. I’ve had the best
success with the wax method. Whatever you choose, make sure the tubing
is annealed first.

Good luck.

Leda


#6

I’ve done it two ways.

  1. Put a piece of wire inside the tube that is has a thickness close
    to the ID of the tube. This method is good if you are not doing any
    complex bends. After you are done bending just pull the wire out.
    NOTE: use the softest wire you can find so you don’t deform the tube
    removing it.

  2. Fill the tube with fine sand, pack it in, and tape over the ends.
    With this method you can very complex bends and don’t have to worry
    about deforming the tube after you have gotten all your bends just
    right. This is the method that I use almost exclusively now. It will
    work with any diameter tubing. I’ve used it alot when doing copper
    sculptures. The big thing to remember with this is “The smaller the
    tubing the finer the sand”. On very small tubing I have even used
    pumice powder.

Shane


#7

There are two approaches to this problem. First use a tubing bender.
Depending on the size of tubing you are working with, you might be
able to get one at the local hardware store. There are two types of
benders, one is a grooved roller with a matching grove bender. The
other type is a closely wound spring that is the exact size as the
tube.

One other approach is to fill the tube with a hard loose material.
Depending on the size of the tubing, you can use fine sand or for
very small tubing, use some 320 silicon carbide grit. You will need
to seal the ends so the filler doesn’t push out, a wood plug will
work. Just make sure the tube is full. Tamp down the filler and
refill until the tube will take no more. You can pick up brass
tubing at some hardware stores and most hobby shops to experiment
with.

Don


#8

Bending tubing of any size is tricky because it tends to crimp and
just fold, like a plastic straw would do. The key is to hold the
walls in place so that they cannot go anywhere but stay cylindrical.
Everyone has their own method from filling the interior with pitch,
sand, ice to filling the interior with rods, a solid core. You can
also preform the area to be bent in anticipation of the distortion so
that after bending it returns to a cylinder. You can also support the
exterior from collapsing inward and expanding in other areas with a
deeply grooved bending jig, like builders use to bend electrical
conduit. My favorite method is to go to the hardware store and find a
steel spring that fits snugly around the tubing (screen door springs
work well). Then bend the tubing slowly and evenly with the spring
acting as a retaining wall all around. Afterwards remove the tubing
by either sliding the spring off.

Good luck.
Alan

Revere Academy of Jewelry Arts
760 Market Street - Suite 900
San Francisco, CA 94102
tel: 415-391-4179 fax: 415-391-7570


#9
I have looked in the archives for on bending small tubing
but did not find anything.  I am trying to make a spout for a
miniature tea pot. In trying to get the proper bend the tubing
collapses. Any suggestions will be
appreciated.

There are at least two ways of tackling this type of job.

1: By using a slightly thicker wall for the tube it may overcome the
problem.

2: If you are using high carat gold fit a silver or copper wire into
the tube to stop the tube collapsing. This can then be removed by
using hydrochloric acid to eat the silver/copper out. Either way you
will need a jig to bend the tube around. In the past I have had a tube
jig made up which consisted of a centre post with a hole drilled into
it to fit the tube into and several different diameter removable
posts fitted around the centre post. by experimenting with the tube
and posts you can get quite tight and neat bends. You will need to
have patience and lots of tube spare for mistakes.

Happy bending

William Russell - in warm and overcast CAIRNS Australia


#10
I have looked in the archives for on bending small tubing
but did not find anything.  I am trying to make a spout for a
miniature tea pot. In trying to get the proper bend the tubing
collapses. Any suggestions will be
appreciated.

Greetings;

What do you mean by ‘small’ tubing? Thin wall, thick wall?? First
ANNEL, to soften your tubing

1: soft solder thin flat stock to one end. Pour fine powder, filling
tube. Slowly bend tube over any round form, same diameter as bend.
Remove powder, heat and remove cap

2: fill tubing with many fine stainless wires, allow extra leangth on
both ends. Do your bending as above, when finished, pull wire strands
out of tubing, one by one

3: find a long spring that just fits inside of tubing. Large hardware
stores have a good selection. Install, do your bending, pull out
spring…

Do enjoy
Dave(18k)

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#11

There are several ways that this can be done. The tube can be filled
with something such as bees wax or sand before bending and water may
also be frozen in the tube before bending.

Also this is an excellent book that will help you understand about a
shaping method known as shell formation. Form Emphasis for Mealsmiths
by Heikki Seppa. It’s an old book but I think that it’s still in
print.

Marilyn Smith


#12

Dear Carob Tree,

tea-pot spouts are normally (traditionally) made from a template and
repoussed into shape from two halves, which are then hard-soldered
together. However, if you are making a more contemporary or
idiosyncratic spout the usual technique is to draw down the tube
around an aluminium core which supports the outer wall when bending
and shaping. The aluminium is dissolved out with acid when forming is
finished.

Hope this helps.
Kind regards,
Rex from Oz


#13

Traditional methods I’ve read of are filling the tubing with sand and
capping with wax, or filling with wax or pitch. After forming, the
filling is removed through an appropriate method. Finer tubing can be
filled with a wire of slightly smaller inside diameter than the tube,
and the wire can be pulled through afterward if desired. It would
probably be advisable to lubricate the wire if you intend to remove it
after forming. An added extra bonus… I’ve also heard that brass
musical instruments are formed by filling with water then freezing to
ice.

Hope this helps!

Dave

Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com mailto:dave@sebaste.com


#14

Try filling the tube with sand and sealing the ends with tape before
bending. Pack it as tight as you can by hand. If you’re handy with
tools make and use a bending jig. Bend slowly!!


#15

I don’t know what diameter tubing you are trying to bend but if it is
large enough to fill with fine sand this will keep the sides from
collapsing. Just fill the tubing up and cap off the ends sufficiently
to keep the sand in the tube until you have bent it to the desired
shape. I have used this on larger tubing when I did not have a tube bending tool.


#16

Micro-Mark sells small tube benders, they have a catalog and also are
online. Essentially they look like small coiled springs that you put
into the tubes after annealing and carefully curl the coils.

Perhaps you can use one of the wire coilers that are so popular now
for wire beads and coil wire very tightly and insert that into the
tube. These are available at craft stores such as Michael’s or online
from <www.wigjig.com>

Teresa


#17

I make hollow bracelets that are bent around a wooden jig. I was
taught to make them by filling the hollow with dop wax (wrap masking
tape at one end, crimp the tape closd leaving a little air space for
the wax to flow out of the tube. Bend around the jig, and melt out the
wax.)

I have tried using other fillers (salt, pumice, etc.) but the wax
works best as it does not allow much distortion in the cross section
of the tube while it is being bent.

Gail Middleton


#18

I don’t know if this is practical on tubing as small as you are using
but, I have bent eighth inch copper tubing as follows;

  1. Fill tube with fine sand.
  2. Wet the sand, then drain.
  3. Tap the filled pipe in the vertical position to get as much settling as
    possible.
  4. Repeat 1 and 2 until the pipe is filled to both ends with wet, settled
    sand.
  5. Close the ends with a firmly inseterted plug, or crimp the ends and
    solder.
  6. Carefully (slowly) bend the tube around a form.

Bill in Orlando


#19

Medical companies use a low melting point alloy called Bismuth and it
melts at 117 deg F or 47 Deg C. You may fill the tube with the molten
metal and let it harden. This will now bend as a solid bar. Immerse
the item in hot water and the alloy will melt out leaving a clean
tube. The material once the water has cooled can be collected and
re-used time and time again. A melting pot is available along with the
alloys from Small Parts in Hialeah/Miami. 1-800-220-4242

Best Regards.
Neil george
954-572-5829


#20

Here is a link to Micro-Mark’s website showing their tube bender:
http://www.dxmarket.com/micromark/products/60360.html

They also have a tool that will ‘curve’ small metal strips and tubes:
http://www.dxmarket.com/micromark/products/81356.html

I just order the tube bender, I’m looking forward to using it. Hope
this helps out.

Also, Suzanne, read the fine print on Harbor Freight, their ‘free
shipping’ normally relates to purchases of $50 or more.

Terri Collier
Dallas, TX @scollier