When bending tubes be they small or large the trick is to have
something in it that will keep the tube from collapsing. You can use
either salt, sugar, fine corundum powder, fill the tube good, stamp
the filling and cork it with wooden corks in both ends and then
simply bend it to the desired shape.
Another way to go is to insert a wire of iron or brass and then after
the bending simply etch the wire out with an appropriate etchant.
Thirdly, there is a special metal for this purpose, at least
available in Europe, with the name of ‘easybend’. It has a melting
point just below 100 degr. C. If your tube is big enough, you just
melt the easybend, pour it into the tube and let it solidify here.
Then bend your tube, and remove the easybend by boiling it in water.
As easybend however contains lead and other not so pleasant metals,
it is recommended to afterwards put your piece in a hot solution of
hydrocloric acid and add some hydrogeneperoxide.
Using a spring sounds like a great idea, but I hear one person saying
to put the spring on the out side of the tube and one putting the
spring on the inside. Could there be an error in posting or is it
just that there really are two way to do this that will work.
Roxan in Pa.
Suggestion: Fill the tubing/spout with Low Melting Point Alloy (Melt
points can be had as low as 117 Degrees Fahrenheit which is very
expensive [about US$135/lb.], or the next higher melt point, 158
degrees Farenheit, which is less than US$20.00 per pound last time I
checked. Brownells carries the 158 degree version (www.brownells.com),
calling it “Cerro safe”.Fill the tube with melted alloy, suggest
coating interior with silicone spray, bend, put in small pan with
clean water and slowly heat till all metal is melted out… Jim
Skladany.
They are not pure Bismuth which melts at 271.3 C (520.3 F) they are
Bismuth alloys. These alloys are called Fusible Alloys and have
several trade names like Cerro Bend and Cerro Safe. They are made up
of Bismuth, Tin and one or more of the following Lead, Cadmium,
Indium. and Mercury. There is one alloy that is probably good for
bending and forming support that does not contain lead it is 31.5%
Bismuth, 16.5% Tin and 51% Indium. It is however very expensive due
to the Indium content. One web site with a whole range of these
alloys, their compositions and melting points is http://www.canfieldmetals.com/aloyprod.htm , there are many other
makers of these alloys.
Unless you buy the lead,mercury and cadmium free versions of these
alloys you must use proper working, handling and storage procedures.
I certainly would not use them on flatware or hollowware that might
possibly be used for food or drink.
With that said I have used them and they are the best way to bend
tubing into complex forms without kinking the tube.
Jim –
James Binnion Metal Arts
4701 San Leandro St #18
Oakland, CA 94601
Phone (510) 533-5108
Toll Free (877) 408 7287
Fax (510) 533-5439
@James_Binnion
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