Can a bent mast be straightened?

O

Offramp

New Member
My Sunfish mast is bent slightly. The bend is at the point where the mast just exits the mast socket. Not sure if I got a bent mast with this 1973 SF this spring or if the mast got bent during a pretty windy regatta a few weeks ago.
Can a slightly bent mast be made straight again? I was daydreaming and trying to convice myself that If a conduit or pipe can be bent with a conduit or pipe bender, can the bender be used to straighten out a slight bend?
Does the bending and straightening cause some lose of strength to the mast?
I picked up a new mast Sunday but I am hoping to straighten out the bent mast and then add an aluminum reenforcement sleeve for extra strength and keep the mast as a spare or for my 2nd sunfish. (Assuming that there isn't a reenforcement in the mast already. I don't yet know the age of the mast. The Fish is a 1973 but I don't know if the mast is original.)
 
It can be done. The procedure will vary depending on what you have to do the job. Here is the way I did it.

First I used a hole saw to cut a 2 1/4 inch hole in a short piece of 2x4 and then cut it in half to make two pieces of wood with U shaped cuts which I used to keep from flattening the mast cross-section when I bent it.

I put the bottom of the mast under the bottom shelf in my heavy workbench and some blocks under the mast about 18 inches up the mast where the bend started (it was a sleeved mast). I then put one U shaped block on top of the bottom of the mast under the shelf and one U block under the mast on top of the other blocks.

I then pushed down on the top end of the mast to straighten it. I had to push very hard and bend it quite a lot to get it straight but it worked and I got it very straight.

Unless you did this many times the mast won't lose any strength.

I'm not too happy with Vanguard because I also bought a new mast and guess what, I just bent the new one.
 
In the preceeding process, you can also fill the mast with sand to help it resist denting and kinking during straightening. After it's straight swap end caps and put your reinforcement sleeve in a fresh end.
 
Thank you both for the tips... Very helpfull info.

FYI. My son asked me for the bent mast. When I asked him what he wanted it for (since he doesn't have a Sunfish) he replied, he wanted to use it for a Festifest Pole . I bummed him out by saying I might need it in the future.
 
It is my experience that the answer is: sometimes.....

Alternating the direction in which you thread the halyard
through the cap does buy you time, but does not preclude
the inevitable.

When things have progressed too far, flip-flop the mast by
swapping the base and mast cap, and restart the process.

If I may suggest, make aware, in a separate correspondence,
your local dealer and ISCA board member of the mast failure.

Remove the 'silverly colored brand sticker' to reveal the extrusion batch number.
Report this number as well as the wind & wave conditions and your vitalstatistics.

Thank you and good luck.
 
I think the idea of using a sleeve to solve the mast bend problem is a flawed idea. With the Sunfish rig, the entire load causing the mast bend is essentially applied to the top of the mast. Since this is 9 feet above the deck, the bending moment is more-or-less 9 feet times whatever that force is. If you put in an 18 inch sleeve, the moment at the top of the sleeve would be 8.5 feet times the load or with a 2 foot sleeve 8 feet times the load. Therefore, the maximum stress would decrease by a factor of 8.5/9 or 8/9 or roughly to 94% or 89% of the non-sleeved case. So, even though there is some improvement, what happens is that the mast bends at the top of the sleeve rather than at the deck.

I don’t know what alloy they are using (they won’t say), but, I suspect it’s weaker than 6061-T6. Whatever it is, I think Vanguard engineering should re-look the situation and consider a stronger alloy.
 
Bad idea. Any metal will lose its tensile strength by straightening. It will probably be OK under calm conditions but would not trust it in a blow.
 
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