Bending SS Tubing

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Joe Bleau - 25 Mar 2006 21:41 GMT

Anyone in this group had any experience bending SS tubing? I can do
basic welding of SS but am fuzzy on bending procedures. A couple of
tricks I have heard involve packing the tubing with sand and
construcing a wooden die to form the tubing.

I can visualize construcing a wooden form to do the bending but I can
not visualize how to force the tube around the form. Perhaps one
could use a come along?

Suggestions appreciated.

Joe

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Matt Colie - 25 Mar 2006 23:00 GMT

Joe,
You neglected to include three IMPORTANT pieces of information:
What is the diameter of the tubing you plan to bend?
What is the wall thickness of said tubing?
What is the smallest radius you plan to bend said tubing to?
These are all things that need to be considered.
Matt Colie

> Anyone in this group had any experience bending SS tubing? I can do
> basic welding of SS but am fuzzy on bending procedures. A couple of
[quoted text clipped - 8 lines]
>
> Joe

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Joe Bleau - 26 Mar 2006 03:34 GMT

>Joe,
>You neglected to include three IMPORTANT pieces of information:
[quoted text clipped - 3 lines]
>These are all things that need to be considered.
>Matt Colie

Matt--

The tubing is one inch 316L stainless. I have not yet measured the
radius but it for the bow of a 41 ft. sailboat. The bend will be
about 170 degrees. The wall thickness is .065.

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Glenn Ashmore - 26 Mar 2006 02:08 GMT

If you are talking about 7/8 & 1" stainless for pulpits you better find
someone with the right equipment or you will end up with a lot of expensive
junk. Sand packing works OK on softer material but is not really going to
help with stainless and 1" tube on anything under a 12" radius will require
hydraulics or a looong lever handle.

Bending polished stainless tube with decent results requires a set of
polished dies built to exact diameters. I built a couple of benders, a roll
bender for long sweeps and a hydraulic for the tight ones.
http://www.rutuonline.com/html/tube_benders.html
You can get plans and dies here: http://www.pro-tools.com/200k.htm . A
set of dies for 1" tube costs about $180.

Signature

Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

> Anyone in this group had any experience bending SS tubing? I can do
> basic welding of SS but am fuzzy on bending procedures. A couple of
[quoted text clipped - 8 lines]
>
> Joe

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Joe Bleau - 26 Mar 2006 03:40 GMT

Glenn--

I am with you. Here is my problem. My boat is in the Fla. Keys. I
have tried everywhere to find a shop to do this for me. The last guy
took a deposit and then kept me waiting for months. He just returned
the deposit saying that he was too busy to do the job. If I am going
to get it done I am going to have to do it myself.

I have thought that I might try to form it exactly with something like
EMT and then take it as a model to a shop in Miami to do the job. No
hoe of getting it done here in the Keys where most all of the trades
have been driven out by the cost of living. Also, there is a disease
down here known as "Keys disease." The syptoms are chronic laziness
and the abandonment of all work ethic. It's always been difficult to
get anything done here and the 200 per cent increase in property
values in the last four years has done nothing to alleviate the
situation.

>If you are talking about 7/8 & 1" stainless for pulpits you better find
>someone with the right equipment or you will end up with a lot of expensive
[quoted text clipped - 8 lines]
>You can get plans and dies here: http://www.pro-tools.com/200k.htm . A
>set of dies for 1" tube costs about $180.

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Matt Colie - 26 Mar 2006 05:21 GMT

OK Joe,

Now we have enough information to be serious help (been there-done that-didn't
buy the picture and the Tshirt has worn out).

To successfully get a pulpit made with out the boat handy you need:
A ridged model of the desired shape (you are planning that), and
An Exact replica of the deck (or whatever you expect to fasten it to.

The first item you do seem to understand, yes, thin wall EMT will work just fine
but the bender does a smaller radius than you will want. So, you dummy it up by
making a bunch of partial bends separated buy a little distance. There are no
T's available for EMT, so you screw hubs into a pipe T (yeah, it looks like
hell, but it serves and it is less kluncky than using a jake).

Next, to create the replica of the deck is interesting. Most decks are cambered
and nothing is square, flat, straight,vertical or horizontal. You can
effectively measure the camber of a deck by putting largish dowels under a 2*4
so that they contact the deck at the mount locations and then measure and record
the separation and between the straight edge and the deck. I have had success
duplicating this by taking a heavy piece of plywood (3/4) and a light piece
(1/4). Planing (a belt sander will work) the edges of the light ply then
clamping it down at the edges with battens under it, to make the separation
match what you measured. This need to be glued when you are sure it is right.
I do hope I didn't loose you along that track. If I did, I will gladdly try
again.

Now that you have a model of the deck it will fasten to and a model of the rail,
you can go find a fabricator on the mainland.

Just be sure that he has done this sort of thing before, or he will screw it up
on the first couple of trys and then charge you for the material used.

Good luck

Matt Colie

> Glenn--
>
[quoted text clipped - 26 lines]
>>You can get plans and dies here: http://www.pro-tools.com/200k.htm . A
>>set of dies for 1" tube costs about $180.

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Glenn Ashmore - 26 Mar 2006 05:28 GMT

Your best bet is to take your measurements, a sketch of what you want done
and a lot of pictures to a fabricator in Miami if you want a good job done.
Ace in Ft. Lauderdale does good work too. Most of them work in 304 tube
though. You may have to provide the 316. yourself but OTOH they will
probably be able to get a better price than you can. They can also TIG weld
the joints which can be a lot more complicated to get right than the
bending.

Even at the price I paid it is not worth the risk of doing it yourself
without the right equipment. My benders cost less than $400 to build but I
have $20K worth of tools to build them with.

Signature

Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

> Glenn--
>
[quoted text clipped - 29 lines]
>>You can get plans and dies here: http://www.pro-tools.com/200k.htm . A
>>set of dies for 1" tube costs about $180.

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Richard van den Berg - 26 Mar 2006 12:58 GMT

> Anyone in this group had any experience bending SS tubing? I can do
> basic welding of SS but am fuzzy on bending procedures. A couple of
> tricks I have heard involve packing the tubing with sand and
> construcing a wooden die to form the tubing.

The 25 mm dia, 1,5 mm thick tubes on this boat I bent myself
http://www.home.zonnet.nl/whitehorse/ The corner with a fixed radius
bender. After bending the corners I filled the tubes with "bird sand"
and towed the tubes together.

> I can visualize construcing a wooden form to do the bending but I can
> not visualize how to force the tube around the form. Perhaps one
> could use a come along?

You know stainless, though as hell, it has to bend more than the disired
shape.

> Suggestions appreciated.

Go to Glenn, I'm jalous on his bending machine. ;-)
Good luck.

Signature

Richard
http://www.inter.nl.net/users/schnecke/catharina/

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Boat Forum / Building / March 2006

Bending SS Tubing