Bent Mast

Submitted by Bruce177 on Wed, 08/25/2004 - 15:41
Today, while raising the mast, something hung up, the mast hinge pin popped out of the mast heel and down she came behind me. Great! Now I have a side bend of 10 degrees about 12 inches above the hounds with a crease. (No damage to transom at all) Is this fatal to this mast? If I could bend it straight enough to look right, will it be usable? [:(]
‹ Stripping the paint? Repairing centerboard 'ears' ›

Comments

The kind folks at Flying Scot can fax you a sheet on straighteni

Submitted by FS5257 on Sat, 08/28/2004 - 09:48.
The kind folks at Flying Scot can fax you a sheet on straightening the mast that worked well for me.

The crease could be a minor problem, but usually it is only cosm

Submitted by Hot Wheels on Sat, 08/28/2004 - 19:48.
The crease could be a minor problem, but usually it is only cosmetic, unless it is right at the hounds [where the shrouds and jib halyard attach.] Once you get it straight again, it should be fine to use. I've seen some sticks with real nasty looking dents perform fine.

This is a plug for Master Helper II, the mast-raising device sol

Submitted by rlarson on Sat, 08/28/2004 - 20:47.
This is a plug for Master Helper II, the mast-raising device sold through Flying Scot Racing. It is absolutely the best for controlled mast raisings/lowerings. This summer we were at Schroon Lake where the area for rigging up/down near public boat ramp was on a significant incline. Master Helper allowed us to raise and lower the mast without the slightest mishap. (We had numerous spectators). If we had got hung up, everything would have been under control. I really recommend this great device.

WHOA! Any mechanical/structural engineer will tell you that a m

Submitted by FS4049 on Tue, 08/31/2004 - 08:33.
WHOA! Any mechanical/structural engineer will tell you that a mast is a thin-walled tube, like a soda straw, and it will be greatly reduced in column stiffness and strength with a wall defect such as a crease. The fact that your "crease" (read plastic deformation of the aluminum) is above the hounds means that it's unsupported and WILL fail especially when the wind is flowing from the uncreased side toward the creased side. Check with your insurance company. They should cover a new mast section and you can still use your existing rigging. If on the other hand, you have a mast that has only a slight bend (no visible plastic deformation) it can usually be straightened by supporting the mast equidistant from the center of the bend arcing up and carefully pressing down on the bend (slight bouncing helps). Remember that aluminum is a unique metal that once bent and straightened becomes work hardened and much more bittile in the area of the bend. Good Luck. Bob Klein FS4049

Amen Bob! Bruce.

Submitted by FS3403 on Wed, 09/01/2004 - 00:28.
Amen Bob! Bruce...bummer dude......I hate when that happens! Seriously though the operative term in all this is 'crease'. In commercial aircraft repair/rework this condition is equated to a crack....the material is already considered to have failed. Having said that...it doesn't necessarily follow that the mast is considered scrap....rework/repair is possible. However the repair cost would likely exceed finding a good second hand replacement. Friends here experienced a broken mast on an S2 7.9....it fell while in the slip! Being out of production at the time a suitable replacement could not be found so a sleave repair was performed and has worked well for the last few years. Your mast could be straightened....crease cut out...and doubler welded in place (both sides?)....but it likely would adversely affect racing performance and only be acceptable for cruising. I would not be comfortable with merley 'straightening'....particularly with friends/family on board in a blow! Another way to look at it......the boat's diminished value from such a flaw would ...again....likely exceed a used replacement mast cost. I'm sure someone out there has an extra mast....heck these things even show up on E-bay! I know....here's a new string...."101 uses for a bent Scot mast" Davit reinforcement, flag pole, garden border ........ Forest engineer FS3403

My thanks to all respondees for your advice.

Submitted by Bruce177 on Wed, 09/01/2004 - 09:39.
My thanks to all respondees for your advice. I will be looking for a good used mast or biting the bullet and have a new mast shipped. I only cruise but I do push the ol' girl and don't need other problems when guests are aboard. Also,the Master helper will be part of my ancillary equipment from now on. I miss being out on her right now. Regards, to all - Bruce 177

Since the Scot mast is untapered, it is oversize above the hound

Submitted by Hot Wheels on Wed, 09/01/2004 - 13:52.
Since the Scot mast is untapered, it is oversize above the hounds and could handle a small ding easily up there. When Scot masts fail, it is below the hounds [no spreaders or lower shrouds like a Lightning rig] It would have to have one heck of a crease to fail above the hounds.

I am no engineer but if the crease is above the shroud and fores

Submitted by Dave812 on Thu, 09/02/2004 - 11:01.
I am no engineer but if the crease is above the shroud and forestay attachment point it may not be that serious. The loads up there are relatively light and even if it failed the rig is still supported.

Not one of my better stunts.

Submitted by Hot Wheels on Thu, 09/02/2004 - 12:40.
Not one of my better stunts....At the Scot Canadian Nationals 2 years ago after the last race, we were unrigging the boat, which has to be done in the water there due to a pedestrian bridge over the launching ramp. I was ready to drop the rig at the dock, having disconnected the forestay, with the spinnaker halyard attached to the stem fitting holding everything up temporarily. The call to the awards ceremony was made, I left the boat at the dock for about 20 minutes. When I returned the mast was horizontal, laying across the aft deck. Fortunately nobody got hit. Don't know how the halyard came loose. Damage was a crushed sailtrack on the back of the spar below the hounds where it must have crashed onto the deck edge. I gently took a fat screw driver and a slim-jim and pried the track back open. It is not noticable and I have since raced in some very big breeze with big waves with some very heavy crews, loading up everything to the max. Stick still stands proud. I know of a Sonar [23' racer - tapered mast] with a ding about 2 inches above the hounds that I can fit my thumb into, that has been raced hard that way for over 10 years with no ill effect. Basically the load above the hounds is not very great especially on an untapered extrusion with no backstay.

Hot Wheels I feel your pain.

Submitted by FS4049 on Fri, 09/03/2004 - 11:58.
Hot Wheels I feel your pain. A dented sail track is easily straightened with careful prying and bending. It is also a NONSTRUCTURAL part of the mast. On the other hand, a CREASE is plastic deformation of the tube wall. The fact that it falls above the hounds means that there are no shouds to help support it in the vertical column. It's a known fact the fractional rigs such as the Flying Scott, the Ericson 30+, Stiletto and Hobie catamaran, all have their upper sections flex to leeward when bearing away (especially on reachs). If you sight up your mast you can see it with your naked eye. The crease, especially in the side of the mast such as is this case, breaks the strain loads on the skin of the mast causing something known as a stress riser, a point in material that concentrates the stresses and becomes the initial point of failure. As an engineer, I deal with this kind of stuff every day. I'm not saying the mast will fail. I'm just saying that if it does fail, it WILL do so at the crease and at a much lower load than the stock section. Good Luck.