Bent Lower Mast

Thread starter #1
I was racing at laser midwinters in clearwater and on the last day my upper broke at the rivet and my bottom bent significantly. Anyone out there know if the lower can be re-bent or if buying a new spar is the only option.

Phil
 
#5
Before you chuck it (following unsuccessful attempts to get it straight) you may consider taking it to a machine shop fix it person. I had a badly bent upper and a guy in our town got it perfectly straight for 15 bucks.

The lower would probably cost more,but no where near the 200+ for a new one.

Mike
 
#6
You trashed both? Ugh, plus I assume the sail ripped also. That makes for a long day. What year spars? and radial or full?

I'd rebend your lower, if it's a full rig, then use it for training. If it happens twice, then end-for-end it. A big guy at our club bends them for us, with the butt between two trees. Reassemble the broken top enough to use it for leverage.

If it's a radial bottom you can't end for end it. Also, keep the trees away from the place where the inside liner ends, or it will get a dent there.

I bent a top at Jensen Beach by deathrolling a radial in 5 foot of water. It came up with a lot of oozey mud. We straightened it, then I reversed it, and will keep it as a spare. It straightened out quite easily (too easy!).

Al Russell
182797
 
#11
Rebending lower masts (both radial and standard) is really hard cause well, they tend to prefer getting ugly dents instead of actualy bending back.
Upper masts is easy though, just put some bodyweight on it and it'll bend back.

You trashed both? Ugh, plus I assume the sail ripped also. That makes for a long day
If you got some sewing skills you can fix the sail yourself, if you don't, leave it to some local sailmaker and let them fix it. Shouldn't be expencive at all =P
 
#12
I have succesfully used the folowing procedure to straighten a radial lower section. First you need to find a some material that is at least the length of the section and significantly stiffer in bending. I have used a piece of 50 by 200mm oregon edge on. Strap the bottom end of the mast to one end of the beam, say at least 6 turns of 6mm rope with a clearance block of say 20mm thickness between the mast and beam. Rotate the bent mast so it is curving away from the beam and support the high point of the bend with a wood support block at least 300mm long 20mm thick and a thin, say 10mm 50mm long pivot block between the support block and the beam. The idea of the 300mm long support block is to reduce the contact stress and ensure you dont dent the mast. You then need to devise a method of applying force to the free end. I like using a block and tackle system made out of pulleys from my bits box. A 5 to 1 system should be adequate. Using your system gradually force the section straight. You will have to overbend the section so that once it has sprung back it ends up straight. Apply a measured deflection, remove the applied force and measure how much you have starightened it. Keep on increasing the applied deflection until you end up with a straight section. You may need to adjust the support block thicknesses to allow enough room to apply the necessary deflection. Have fun, and good luck!
 
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