Bent Spar

[Rolias]

Help. Rolias Hull #765 was involved in the Stoughton Tornado that went through southern Wisconsin last Summer. She luckily survived without too much damage but got laid over on the shore and the spar now has an 8" banana bend to it beginning about 2/3 of the way up the mast. Any ideas on how to straighten extruded aluminum.? This is the original mast and I really do not want to replace it.

[Peter McMinn]

My understanding of aluminum is that bending it back into shape usually weakens the metal even more. I don't think I'd want to put a mast that's suffered this through the stress of normal sailing.

By 2/3 of the way up the mast do you mean the bend is above the spreader line?

[michaelyogi]

I agree with the above. Straightening bent aluminum is not a good idea...

[jpclowes]

A guy I sail with works with a bunch of metalurgists (SP?) He says that they claim that as long as the metal is not cracked, wrinkled, or kinked, it will be just as strong as it was pre bend. I know that is kind of 4th hand information now, and it might be kind of hard to trust, but it might be worth exploring further. But as a guy on another message board I frequent says "...at your own sole risk."

[calden]

I'm no metallurgist, and don't know how to weld, but here's an idea:

If the bend isn't too severe -you stated it was an 8" banana bend, which might mean it is only 8" long, but doesn't indicate the angle of bend - you might be able to straighten it then rivet/weld a couple of stiffeners on either side, like 1"x12"x1/4" (or longer, depending on the area bent) pieces of aluminum. I'm sure this would violate any class-legal specs. But if you wanted to keep the original mast, you could do this, and I bet it would be fine. After the weld you might grind down the raised edges so what you then have are a couple of smooth humps.

Just some creative thinking, don't know if it's practical or not, but it seems it would be.

Carlos

[Bob Damon]

I have straightened several mast sections with minor bends like this by securing one end of the mast and then blocking the area under the opposite side of the bend and gently pushing rhymically down on the mast. Stair steps off a deck work well. It works best in very hot weather with the mast exposed to direct sunlight for several hours. For a more severe bend I also have attached a cinder block to the end of the mast again with the opposite side blocked let it hang to keep some prolonged pressure on the mast after the rhymic bouncing. The idea of using the stiffeners is also recommended or you can use a mast chafe collar from Proctor that wraps nearly all the way around the mast.

[John Zinn]

The mast of our daysailer was bent as a result of another boat catching the shroud with their boom and breaking the sidestay. Actually, it was during the starting sequence on a windy day and they had the right of way but that is another story!
Once we got on shore the mast had a gradual bend in it, probably 6-8 inches. I set up the heel of the mast under the club shelter and found several fulcrums because it was a compound bend. The weather was warm so the mast was more pliable. Working slowly I bent the mast in the opposite direction from the way it had bent and got it veery close to the original, but not quite right.
I continued to use the boat like this for a couple of years until I sold it and did not have any failures. It acutually sailed about as well as before and was good enough for club racing, although not extremely competitive, but that's more of a problem wiht the skipper!