Unbending Aluminum Pipe?

Wade Lippman

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Apr 28, 2003, 6:50:11 PM4/28/03

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My boat hoist, with a 400lb boat in it, was moves 12 feet and turned around
by ice this winter. Live and learn.

Anyhow, one of the legs is slightly bent, with a bit of a dimple on it. It
needed to be "tapped" with a sledgehammer to get it to go down so I could
get the boat off it. It is fairly light aluminum, about 4" in diameter.

Any idea how I can straighten the leg, without damaging it further? It
can't be too bad, or I never could have gotten it down, but I can't go on
using the sledgehammer.

cornytheclown

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Apr 28, 2003, 9:49:36 PM4/28/03

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"Wade Lippman" <tol...@frontiernet.net> wrote in message news:<Deira.1231$Jc3...@news02.roc.ny.frontiernet.net>...

take it to an auto body repair shop

Chuck

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Apr 28, 2003, 10:25:51 PM4/28/03

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Once a pipe gets a dent or a kink in it, it will be significantly weaker at
that spot, no mater how well you 'repair' it. The metal gets 'fatigued' when
bent.

"Wade Lippman" <tol...@frontiernet.net> wrote in message
news:Deira.1231$Jc3...@news02.roc.ny.frontiernet.net...

Jim Yanik

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Apr 28, 2003, 11:31:45 PM4/28/03

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"Wade Lippman" <tol...@frontiernet.net> wrote in

news:Deira.1231$Jc3...@news02.roc.ny.frontiernet.net:

Perhaps it would be better to replace it.Once a tube is kinked or
dented,it's strength will never be as original.

--
Jim Yanik,NRA member
remove X to contact me

Larry Caldwell

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Apr 29, 2003, 5:09:49 AM4/29/03

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NoS...@NoSpam.com (Chuck) writes:
> Once a pipe gets a dent or a kink in it, it will be significantly weaker at
> that spot, no mater how well you 'repair' it. The metal gets 'fatigued' when
> bent.

You can fix that by annealing.

--
http://home.teleport.com/~larryc

Jim Yanik

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Apr 29, 2003, 12:29:21 PM4/29/03

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Larry Caldwell <lar...@teleport.com> wrote in
news:MPG.1917e0d06...@news.earthlink.net:

> NoS...@NoSpam.com (Chuck) writes:
>> Once a pipe gets a dent or a kink in it, it will be significantly
>> weaker at that spot, no mater how well you 'repair' it. The metal
>> gets 'fatigued' when bent.
>
> You can fix that by annealing.
>

Bending and rebending the metal will still leave it weaker than original.It
will never be the same,or as strong,and prone to give way in the same place
as it was originally bent.

JTM

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Apr 29, 2003, 4:38:43 PM4/29/03

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"Wade Lippman" <tol...@frontiernet.net> wrote in message
news:Deira.1231$Jc3...@news02.roc.ny.frontiernet.net...

If the dimple is smooth in contour with no crease on the margin of the dimple
then you may be able to push it out from the inside. You will have to have
access to the ends of the tube for this to work. Find a metal cylinder of steel
pipe or solid bar stock (mandrel) which will just fit the undamaged interior of
the tube. Chamfer the edges of the cyclinder and lubricate it with
molydisulphide grease. Fasten an eye bolt to it and hook it to a come-along so
you can pull it through the tubing until you get it centered on the dimpled
area, then using a brass or soft metal hammer tap around the dimple until it is
smooth. remove the mandrel and you have it good as new. Don't worry about
weaking the pipe as long as the dimple did not result in cracking or creasing
the pipe. This proceedure will if anything work harden the dented area and it
will be less likely to bend at the same point in the future.

After the dent is removed the pipe may fortuitously straighten out. My bet is
that it may actually bend the opposite way since you will have stretched the
dimpled area in the process of removing the dent. Run a taunt line from one end
of the pipe to the other and if the maximum offset is less than a 1/8" per foot
of length you will be ok.

You may have to use schedule 40 or 80 iron pipe to get the right outside
dimensions.

Regards,

John