| Slightly bent and slightly dented mast #166613 01/29/09 02:07 PM 01/29/09 02:07 PM |
Joined: May 2005 Posts: 39 Dallas, TX lonestarcat OP
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Posts: 39 Dallas, TX | My mast became bent above the gooseneck after a mishap raising it, when the bottom came off the ball and went to ground.
I read all the threads I could find on the topic, and tried putting it on two fixed objects and applying force with various methods on the bend in the opposite direction. I even left it bent in the opposite direction for 1 week. After releasing it always returned to its original bent shape.
In one post someone mentioned that they were only able to remove the bend by applying heat while straightening the mast.
My question is, Is there any risk of weakening the mast by torching it?
My mast also has a slight dent on one side at the spreader bar attachment. The only solution I have read was by Wouter lowering into the mast a hydraulic device from a body shop to re-expand at the dent. I think these are called porta-power and you need a book press attachment or something.
Has anyone rented such a thing or asked a body-shop to assist in dent removal?
Prindle 19MX
| | | Re: Slightly bent and slightly dented mast
[Re: lonestarcat]
#166624 01/29/09 03:36 PM 01/29/09 03:36 PM | andrewscott
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Unregistered | My mast became bent above the gooseneck how severe is this bend? If it is minor, your sail may not be effected with the pressure of the wind on it. My mast also has a slight dent on one side at the spreader bar attachment I am certainly no structural engineer, and there are several on this forum that may contribute, but it is my guess, understanding, belief... that the attachment part of the spreaders can handle a dent more than the top or bottom of the diamond wires... I have had a baseball sized ding in my mast at the tang (where the main and halyard attach) and i have a spin attached above it and it has not buckled.... | | | Re: Slightly bent and slightly dented mast
[Re: lonestarcat]
#166625 01/29/09 03:41 PM 01/29/09 03:41 PM |
Joined: Jan 2004 Posts: 1,884 Detroit, MI mbounds
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Posts: 1,884 Detroit, MI | My question is, Is there any risk of weakening the mast by torching it? Absolutely. You'll undo the heat treatment that it originally had. Probably too late to file an insurance claim, but methinks your mast is toast anyway. | | | Re: Slightly bent and slightly dented mast
[Re: lonestarcat]
#166629 01/29/09 04:01 PM 01/29/09 04:01 PM |
Joined: Aug 2007 Posts: 1,304 Gulf Coast relocated from Cali... TeamChums
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Posts: 1,304 Gulf Coast relocated from Cali... | Don't even think about heating it. You can't get the bend out by leaving it bent the other way. You will have to put it between two anchor points and keep "wiggling" it to get the bend out. It takes a long time. You will have to push it past the bend in the opposite direction. Take the diamond wires off. One anchor point will have to be at the peak of the bend and on the opposite side near the end of the mast but not all the way to the end. You just have to keep working is little by little. BUT the dent is a huge problem. Do you have any pictures?
Lee
Keyboard sailors are always faster in all conditions.
| | | Re: Slightly bent and slightly dented mast
[Re: SurfCityRacing]
#166633 01/29/09 04:25 PM 01/29/09 04:25 PM |
Joined: May 2005 Posts: 39 Dallas, TX lonestarcat OP
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Posts: 39 Dallas, TX | Thanks for replies. I will post pictures this weekend. I have been sailing with it for about 7 years so it is very durable toast. I am on the hunt for a salvage P19 to replace the mast. I tried staightening it Lee's way ages ago and the bend was unfazed.
Prindle 19MX
| | | Re: Slightly bent and slightly dented mast
[Re: lonestarcat]
#166648 01/29/09 06:15 PM 01/29/09 06:15 PM |
Joined: Oct 2007 Posts: 199 Constanta, Romania isvflorin
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Posts: 199 Constanta, Romania | Bob, depending on how large/big the dent is you can also try to use an air compressor to get the ding out. Use a bicycle tire tube or something than can take some pressure. Put the inflatable tube between 2 rigid parts (best to follow the mast's inner curvature - shape some wooden blocks or something) and get those inside the mast in the ding area - then slowly inflate the tube and check if there's progress.
Bob, I never had to deal with dented masts, this ideea just happened to pop up, it may be very well a bad ideea.
regards,
Florin
| | | Re: Slightly bent and slightly dented mast
[Re: lonestarcat]
#166662 01/29/09 07:47 PM 01/29/09 07:47 PM |
Joined: Feb 2007 Posts: 266 UK Cheshirecatman
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Posts: 266 UK | My mast became bent above the gooseneck after a mishap raising it, when the bottom came off the ball and went to ground.
I read all the threads I could find on the topic, and tried putting it on two fixed objects and applying force with various methods on the bend in the opposite direction. I even left it bent in the opposite direction for 1 week. After releasing it always returned to its original bent shape.
In one post someone mentioned that they were only able to remove the bend by applying heat while straightening the mast.
My question is, Is there any risk of weakening the mast by torching it?
My mast also has a slight dent on one side at the spreader bar attachment. The only solution I have read was by Wouter lowering into the mast a hydraulic device from a body shop to re-expand at the dent. I think these are called porta-power and you need a book press attachment or something.
Has anyone rented such a thing or asked a body-shop to assist in dent removal? Persevere with the reverse bending. I have successfully corrected mast bend with the use of 3" steam pipe underneath a trolley jack. Attach the mast to the pipe with 3" webbing straps and use a sturdy piece of wood between the jack and mast to spread the load. You may be surprised at how far you need to go to permanently straighten the mast. With regard to the spreader ding (sounds like it's been dropped sideways on the spreader) if it isn't affecting mast bend - leave it. Just make sure spreader lengths are 'corrected' to ensure equal mast bend on each tack. If it's a big problem you can always apply an external plate wrapped around the section. A good friend had a good sized ding just above the gooseneck on an 18-2 mast(same section). He welded an external plate to the area and never had any problems on his heavily-sailed boat. Cheshirecatman | | | Re: Slightly bent and slightly dented mast
[Re: Hullflyer1]
#166742 01/30/09 10:13 AM 01/30/09 10:13 AM |
Joined: Jan 2009 Posts: 5,525 pgp
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Posts: 5,525 | Automotive sheet metal is thin and ferrous. I'd have the same concern using extreme temperatures on aluminum, whether high heat or low heat.
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Slightly bent and slightly dented mast
[Re: NacraF18_566]
#166762 01/30/09 12:45 PM 01/30/09 12:45 PM |
Joined: Jan 2009 Posts: 5,525 pgp
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Posts: 5,525 | The (usually) unseen problem is that the existing metal is now stretched. There is physically more area; just as a curved line between two points is longer than a straight line between the same two points. To bring the mast back to its original strength, the metal must be shrunk.
When working with ferrous alloys, like a car body, this can be accomplished by heating and then striking or quenching. I don't know if aluminum has the same property.
Pete Pollard Blade 702
'When you have a lot of things to do, it's best to get your nap out of the way first.
| | | Re: Slightly bent and slightly dented mast
[Re: HMurphey]
#169479 02/25/09 02:04 PM 02/25/09 02:04 PM |
Joined: Feb 2009 Posts: 41 Tampa, Fl deepsees
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Posts: 41 Tampa, Fl | If the bend is still there... you have not put enough force and deflection to surpass the memory of the aluminum. I have not heard of aluminum being heat treated. BUT... putting heat on aluminum is sketchy... it does not glow before it suddenly turns to a liquid.
You have to get past the metal's modulous of elasticity.
Last edited by deepsees; 02/25/09 02:10 PM.
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