Bent dolphin striker

So this happened when the town pulled my boat from the dunes. They made no attempt to contact me to ask me to remove it from the beach myself.

Any thoughts on if the whole crossbar should be replaced? Or if it is significant to recreational sailing.

I don't think I can keep it on the beach anymore. It is listed for sale here and locally.

thanks,
Mayor

[img][img]http://s13.postimg.org/7an4owj43/IMG_1178.jpg[/img]/img]

[img]http://s13.postimg.org/jp9wp8amf/IMG_1178.jpg/img]

Fixed your image link:


It can probably be straightened - gently, with a bit of heat (not too much, or you'll damage the aluminum and/or the trampoline - best to remove the trampoline first).

I'd rig up a come-along from the tip of the dolphin striker to the rear crossbar (use a strap to spread the load), warm up the post a bit with a torch and slowly pull it back into shape.

Actually, I'd be more worried about that rust streak running down the hull. There's some nastiness going on inside the crossbar there.

Thanks for fixing the photo.
The rust is just a stain. Repaired that a few years ago. Someone had used a non stainless bolt on the inboard crossbar. It was a bitc# to get it out...but it's good now.

Use a cleanser containing oxalic acid (Zud, BarKeeper's Friend, FSR, OxyClean) to remove the stain.

I'd bet your mast step is looser now than it was before...

I would check the rivets on the mast step and check all around that area of the crossbar for cracking. You may even want to pull the step off (if you can) and check under it for any cracks. I think the dolphin striker post is something like 9/16" diameter and it would have taken a heck of a lot of load to bend it like that. May have even torqued the crossbar-to-hull attachment bolts. I'd check everything.

Worst case scenario, you've got to cut out the post and replace it which wouldn't be too bad, but most likely the post is seized in the mast step and the dolphin striker rod ends are seized in the crossbar end caps, so it could definitely turn into a project.

sm

Yikes! personally, I wouldn't want to mess with the dolphin striker. Once it's plastically deformed like that, I'd be worried that it's too brittle to bend back, and any attempt could result in micro-cracking that'll set it up for complete failure later on. If the dolphin striker fails, the crossbar loses the reinforcement and added strength of the striker & tension rod, and could buckle under the weight of the mast and the downforce of the rigging (while under sail).

That said, heat on it would certainly help it bend without any cracking. The more heat, the more malleable and the less stress on the material. Of course, the heat will transmit through the entire dolphin striker very well, and too much heat will soften the aluminum crossbar, probably deforming the hole in the crossbar as you try to bend it back.

A new dolphin striker post is only $60. If you loosened up the tensioning rod and slipped the sleeve off the end of the post, you could probably just as easily remove and replace the post. I'd think the tensioning rod is okay and the crossbar is probably fine too, just some minor deformation at the bottom hole. I would check that the mast step doesn't have any cracks, the mast step rivets didn't loosen up, and that the mast step didn't put any cracks into the crossbar on the aft side, but all that seems rather unlikely and looks fine in the pic. I'd check all that stuff either way, actually, and especially if you bend back the post.


On the other hand, your picture just helped me finally figure out what those odd cone shaped parts that came with my cat trax are for!

_________________
Mike

'79 H18 standard 'Rocketman II' sail #14921 RIP
'78 H18 (unnamed) sail #14921
'08 H16 sail #114312
'97 H21SC sail #238

In a perfect world, you're right. But that boat looks like it's spend more than a few years on the beach and I'd be very surprised if the striker post isn't frozen in the mast step and the striker rod frozen in the crossbar end caps.

If it's all frozen up, probably the only way he's going to get it apart is by removing the front crossbar and cutting the post along the bottom side of the crossbar. Then remove the mast step rivets and pull the step and post stump out the top of the crossbar. Then work the striker rod free from the crossbar end caps and either work the post free from the mast step or replace the whole step and post. While it's apart, fully inspect the crossbar for cracking. Then put everything back together with a new post (and possibly new step).

sm

Good point. Being on the Great Lakes, I often forget how much havoc the salt water creates in corroded and seized parts! I was wondering why Matt suggested bending it back vs. just replacing it

Yeah, it would be a production to remove it. It's really not bent that much, and steel can take a fair amount of plastic deformation before it cracks - which, even if you got some micro-cracks, wouldn't be a big deal since the striker is in compression, not tension.

What you will get by bending it back is stress hardening (heat helps with that) and stress corrosion (not much you can do about it).

I would still be concerned about the mast step rivets. They have a tendency to loosen up under normal sailing conditions. With the initial bend and the subsequent bend back of the striker post, you will have subjected the mast step to fore/aft loads that are well beyond normal. There's a good chance you're going to need to re-rivet the step after you bend everything back in place.

If the step does loosen up, take the rivet replacement as an opportunity to inspect the front crossbar under the step for any cracks.

sm

Replace the rivets and post, there cheap!!! Have the piece of mind when you will sail later that you won't have to worrying about the repair.

Corkguy 91 H18SX

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Corkguy H18, Tiger, Wildcat