Bent Boom

[clausont]

Well, this is something that I should have noticed long before now. As I was removing the sails from the boom on our Cal 29, I sighted down the boom and sure enough, it is bent. It is about 2" - 3" out of line. It is bent at the vang attachment point, but oddly enough, it is bent sideways. I could not figure how it would have gotten bent that way.
My question that has probably been covered here many times (but I could not find it when searching) is:
Can this be straightened? There is no kink in it or anything visible unless I sight down the top of the boom. If so, what it the best way to do so?
If not, does anyone know where I can get a replacement extrusion? It is a 2 1/2" x 3 1/2" teardrop aluminum boom. The rigger that helps me will be looking for one. He thought he had one, but it turned out that he did not. I checked with Minneys Yacht Surplus and they did not have anything either.
Due to shipping costs, I hope to find something on the West coast if I can not straighten it.
Thanks in advance

[DeepFrz]

I take it that you have no idea how long it has been like it is. From your comments I take it that it could have been bent for quite some time and doesn't appear to have been a problem. If there are no kinks in the metal and no sign of stress cracks or corrosion why not leave it as it is?

[delmarrey]

I assume your main sail is fastened to the boom by a boltrope. In these cases when one tacks hard over and the boom swings the sail puts a center load on the boom bowing it in the middle.

If the main sheet is attached at the middle, just behind the vang, the boom will swing over and stop where the mainsheet is set but the clew of the sail will continue to travel bending the boom, sometimes permanitly.

If the mainsheet is attached at the end (clew) and the sail is stretched out or has a shelf, especially, it will put a center load on the boom when the sail fills.

I'm betting you have a mid boom mainsheet, the biggest culprit.

As for straightening the boom, if there are no external marks is could be straightend if done properly. But it will be weaker then it use to be. It has to be over bent the opposite way to get it straight again.

If you can find the manufacture it would probably be better to buy a new extrusion and keep your old end castings. There may be a sticker or making indicating the mfgr of the boom. Or even a Cal site forum may know who made the standing rig for that year......................._/)

[hellosailor]

Elevators and printing presses use larger rollers, and there are shops that deal with repairing those rollers--they might be one place to start asking. A local pipe bending shop (mufflers or stainless fabricator) might be willing to tackle it. But I'd also question the strength after that job, and would probably not trust it unless it was also sleeved over/in the entire section that had been weakened. At that point...getting a new extrusion or a similar used boom and transferring the fittings might be cheaper and the more elegant solution.

[clausont]

DeepFrz - You are correct, it was like that when I bought the boat. I have not yet had the boat in the water. I bought it as a complete boat that I knew would take some work to get it in the shape I wanted it in.
I considered leaving it as is for the time being and I will probably do so until I find another boom. I wonder what it would do to sail shape and performance. Of course, I likely would never notice any performance degradation myself. I doubt that I'm experienced enough to know the difference in performance.

Delmarrey - What yo say makes perfect sense. In this case though, it is an end boom mainsheet. I was concerned about strength even if it could be straightened. I have already stripped the hardware off the extrusion with the intent of installing it on another extrusion. If I don't find one pretty soon, I will re assemble it until I do find one.

[Joli]

We've used trees to straighten booms. Sometimes it works and sometimes you end up buying a new extrusion.

Another option is to look around for a broken spar from a smaller boat. I have used J24 spars and Hobie 18 spars as booms on larger boats. A local machine shop may be able to adapt the gooseneck to the extrusion.

[Kanani]

It shouldn't be that hard to straighten. I'd set each end of the boom on a block of wood, then get a couple of people to sit on it and bounce up & down until it is close. You would have to add weight slowely to be sure that you don't overdo it.

As stated, it will be weaker than it was. If the original bent, you can bet the straightened one will bend easier.

I broke a boom out at sea one time. I just happened to have a block of wood on board that fit right inside the boom. I drilled and bolted it in place. I later found a boom to replace it but it worked well even in strong winds.

The reason that I brought that up is because I think that you could adaquately reinforce the boom (after straightening) by stuffing an aluminum extrussion inside.

[DeepFrz]

Ah, I didn't realize that you hadn't sailed the boat. In that case, if it were my boat, I would probably replace the boom and, knowing me as I do, I would probably oversize the replacement.

[Kanani]

Originally Posted by clausont

oddly enough, it is bent sideways. I could not figure how it would have gotten bent that way.

I have seen people put a jibe preventer from the end of the boom and run it out forward, then pull the mainsheet tight to flatten the sail. I can see where that would bend the boom that way.

[Moonchaser2304]

How about leaving the boom the way it is and using the sail loose footed...don't recut the sail, just dont put the bolt rope in the slot? (and see how the sail shape is compared to the boom..and then decide if there is any reason to worry about the boom at all)

[Ishmael]

Dwyer Aluminum Mast Company- Manufacturers of Quality Sailboat Masts, Booms, Hardware and Rigging Since 1963.