The Tornado came with side stay anchors with holes for small 3/16 inch pins. Seems undersized as most now are 1/4 or 5/16. Probably going to upgrade. These are epoxied in. Where do I find parts like this?

Been pushing the boat in swells and a 3/16 pin got bent last weekend.

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John

Nacra 5.0
CT
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Can't you just drill out the hole in the plate to 1/4" diameter?

Otherwise, I would check APS, they tend to have this type of hardware.

sm

It's a tad too small to frill it up. It was probably undersized by the previous owner.

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John

Nacra 5.0
CT
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you are talking about the side stay tang ?

I don't know much about T's but on mystere's they are internally mounted, epoxied in, screwed in the hull side and require deck removal or accessing through the bow port and hacking through a bulkhead - using 5' extensions on tools... not an easy task



Edited by MN3 on Jul 11, 2017 - 08:51 AM.

It does seem like drilling out the tang would be the approach to go with, but even that means lots of other changes. Hard to imagine the tang being so small that it couldn't tolerate the larger hole. Changing the tang would be a very difficult project.

Replacing the pin with a good quality 3/16" pin may also be a good approach. The boat survived a lot of years with the configuration you have. An occasional bent pin may just be the cost of the light rigging arrangement. Bending is annoying, but it is a long way from bending to shearing, which is what you really don't want to happen.

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dg
NACRA 5.2 #400
This End Up
Original owner since 1975
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Can you post a picture of your tang/adjuster arrangement?

It could also be a matter of just bending the "ears" of the adjuster closer together and using a shorter pin so that the pin is purely in shear, not shear and bending. This may not be the best solution, but could help to reduce bending.

I would tend to disagree that bending is a long way from shearing. They are two different failure modes. Bending is the beginning of pin failing (plastic deformation), and once the pin starts bending, the loads change. If it continues to bend, it will either break or it will start to put load on the split ring which in turn may break and then the pin will pull out.

I think changing to a 1/4" pin would certainly provide some peace of mind if possible and this size tends to be the "standard" pin size on most beach cats. A 1/4" diameter pin will have roughly 75% greater shear strength than a 3/16" pin, all else being equal.

sm

Quote

I would tend to disagree that bending is a long way from shearing. They are two different failure modes. Bending is the beginning of pin failing (plastic deformation), and once the pin starts bending, the loads change. If it continues to bend, it will either break or it will start to put load on the split ring which in turn may break and then the pin will pull out.

That is all correct, but a massive amount of bending will take place before a total catastrophic failure , or as you note the split ring comes into play and that would be bad. But bending absorbs loads. Your idea about closing in the gaps makes great sense, if it can be accomplished. Maybe using a nut and bolt above the regular pinning area could pull the adjuster closer to the tang and take out the excess space. Bending can be Ok, shearing not so much.

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dg
NACRA 5.2 #400
This End Up
Original owner since 1975
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I put an image up in my album. It was made from a threaded rod, so it doesn't have much extra material to modify. Overall, its a pretty poor part. The problem was probably the adjuster, but I want to fix everything. We have drilled the rod out, and re-epoxied other fittings so its not new to us (or my sailing buddy who is a super fabricator). It may be called a side stay tang. Just looking to get a strong part. I can machine some steels, but hardened 316 is not easy for me to work with.

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John

Nacra 5.0
CT
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ctcataman

I put an image up in my album.

anychance you can post a side and or bottom view?
I am curious how it is anchored

It is epoxied into the wooden structure. It only sticks up 3/4 inch. I will see if I have some other photos.

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John

Nacra 5.0
CT
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