Bent mast

[jono_howlett]

Our mast on our 19ft dayboat was accidentally dropped while we were taking it down. Now if you look along it theres a distinct bend about halfway along. If you go to where its bent theres no obvious curve and the metal does not seemed to be wrinkled or kinked at all. We have considered trying to straighten it out by trying to bend it the other way but Im not sure this is a wise thing to do.... the mast is aluminium and 30ft long. Will it straighten itself out when its re-stepped and the rigging attached? If re-bending it back into shape is an option is there a recommended way of doing it?

Thanks in advance

jono

 

[sarabande]

there could be two causes to the bend:

1 the mast itself is bent

2 the rigging has been bashed causing the mast to bend under tension from the rigging


If you loosen the rigging, does the bend still appear ? Is so then the mast itself may have experienced plastic deformation from being dropped. (Elastic deformation is when the mast springs back to its original shape; Plastic is when the bend is permanent).

The problem with permanent deformation in a mast is that of compression when it is set up and the rigging is tightened. The forces are quite high, and are likely to exaggerate any intrinsic bend to the point of causing the mast to buckle. This is usually a sudden and expensive event.

A 30 ft mast on a 19ft day boat sounds like a fairly sophisticated and stressed item.


Identify first of all whether it is permanently deformed by taking of all the rigging, and looking along the length as you rotate it.

If it is bent, then see how risk averse you are, or whether you have a good insurance company.

 

[jono_howlett]

Hi sarabande,

The mast is currently down and looking along it show a sharp bend about half way along. I think we can safely say its bent. Any ideas on straightening it. Maybe we'll just learn to live with it.

Jono

 

[vyv_cox]

I have straightened catamaran dinghy masts by supporting each side of the bend and bouncing gently at the bend. These are relatively large diameter sections and perhaps heavier wall thickness than yours, so go easy on the bouncing. A Hobie 18 mast took two people standing at the bend and bouncing in unison. Aluminium is quite ductile and doesn't work harden appreciably, so bending it back should do no damage and be relatively easy to achieve.

These are gentle bends, if yours has a fold or kink it will probably not work and you could fracture it.

 

[onesea]

Aluminium is quite ductile and doesn't work harden appreciably, so bending it back should do no damage and be relatively easy to achieve.

Thank heavens for that, i have been involved with straightening a couple using gate posts and parking bollards...

Gently gently...

 

[Fantasie 19]

A 30 ft mast on a 19ft day boat sounds like a fairly sophisticated and stressed item.

That was my thought to... that's some mast - it's 8 foot longer than the one on my 20 foot boat... what kind of day boat are you sailing???

 

[smth448]

I would not try to "live with it" a bent mast will eventually fail under compression. You could try to straighten it as has already been suggested but if the bend is sharp you may need to sleeve the mast to restore the strength. I would obtain professional advice and inform your insurers accordingly. You may need to obtain a new mast section.

 

[mrming]

That was my thought to... that's some mast - it's 8 foot longer than the one on my 20 foot boat... what kind of day boat are you sailing???

I thought that seems like a huge mast for the boat too . The mast on my generously-canvassed 23" yacht is only 29'. What sort of boat is it?