Need advice: Staysail halyard tang

[ebb]

The staysail halyard tang is diagrammed in the Association Manual on pg 21 and pg 163.

It is a radiused 2.5" square of 13 gage stainless with a 3" long tongue that is bent out over the main sheave.
The tongue has a hole in it for a block.

I found the mast corroded under this fitting. It was so bad that the sheave cut out was open to the top of the mast - with the aluminum corroded nearly through under most of the fitting. I have attempted to fill the area with Durafix, more or less to give the mast top its shape back. Working with Durafix is another story.

Plan to Alumaprep, Alodine, prime and fair with epoxy before paint. That hopefully means that the damage will disappear. I'm not comfortable that Durafix is really a durable fix.


I got some 12 gage 316 sheet from McMasterCarr that a local metal shop says they can bend to the same curve as the front of the mast. I can cut a piece of that curve to fit above the sheave slot and have it go around the sides. Machine screws in a close pattern would be used to lock that plate onto the mast. In effect hold the damaged area immobile. This time isolate the different alloys as best we know how. New painted mast is a start. We can add plumber's tape, LifeSeal, and TefGel to the apartheid recipe.

Some of the screws can go through the stainless plate, through the good parts at the very top of the mast, and into the masthead fitting. Holding all of it together.

Hope it works.
The original tang that caused the problem had the tongue extension bent out and then down.
Don't know about you but I'm uncomfortable with hard thin metal bearing on the halyard block pin. The hole should be bushed to make a fatter bearing surface. Right? But the whole mast is rigged with single plate tangs. And you have to say, fairly successfully for 40 some years.

The new repair plate is a curved rectangle. I could jigsaw in a duplicate tongue extension just as what was there before. It could have a single bend and stick out at the angle of the stay like the diagrams in the Manual!

So here's the question:
Instead of adding that tongue I would like to weld a 'D' shaped ring at a right angle to the repair plate above the sheave box. A squeezed ring like a long chain link so that the halyard shackle clevis pin would have a nice saddle loop to hang out in and be free to move.


Is it OK for this D-ring to be higher than the original tongue that hung over the sheave box? It would be much closer under the forestay attachment on the masthead.

Is the flattened ring (made of, say, 5/16 rod) an improvement worth the expense?
Or is that hole in the tongue OK the way it's always been?:confused:



Anybody have an opinion. please?

[PJM]

I can't help out on the staysail halyard tang (which sounds like it needs some kind of repair in any case), but I can tell you that C-74 runs it's staysail off the spinnaker halyard, with no apparent issue. Not sure if the staysail halyard tang and spinnaker halyard hit the mast in the same approximate location.

Peter

[ebb]

Hello Peter,
Original masthead casting on A-338 was pitted and corroded. Had a replica made of aluminum plate by Ballenger Spars that has a typical stainless spinnaker bail bolted to the top and sticking out about 1.5" from the front of the masthead. A block hanging there could take any position but dead aft.

Did see a picture recently of a forestay setup that looked like the halyard was rigged ABOVE the stay.

So you are saying that it doesn't matter where the halyard block is in relation to the stay. correct?
Good to know.


Like the idea of blocks on bails.
May go with a bent rod / spinnaker bail from the sides of the new mast repair plate (which would then become a tang?)- but have it welded it on. Could be described as like the original tang but wrapped around the mast sides. Like the spinnaker bail get it to stick out away from the sheave box so that the halyard block hangs clear of the main halyard and the new sheave box.
The original stainless halyard tang is history.
It showed absolutely no corrosion on the side against the mast.
There is no reciprocating galvanic action evident on the fitting. The victim definitely was the mast.

[commanderpete]

Would you have access behind to bolt on a bail or bent tang?

[commanderpete]

I wouldn't expect more than a few hundred pounds strain on the jib halyard anyway.

Although I gave my halyards a workout the other night.

I went to retrieve the anchor and it wouldn't budge. Couldn't bring it up. Eventually I let it slack, pulled forward and dropped another anchor. Then I drifted back on it and winched the anchor up till I reached the chain.

I put the main halyard on it, then the spin halyard, and slowly managed to winch the anchor clear of the water.

Turns out there was a big chain snarled around the anchor. Whatever was on the end of that chain was not coming up (I was hoping to at least get a new anchor for my trouble)

Of course, this kind of stuff only happens to me

[ebb]

Man! the second I saw it I could smell it! that anchor comes thru here in the kitchen with the smell of anaerobic muck, rotting iron and salt bay!

Yeah, these plates, been looking into them. Here's the first tickler:
The plates have to be attached with either #10 screws or 1/4". (Probably have to redrill many plates for 1/4" holes) Size #12, a personal favorite, is being phased out by the hardware mafia. It's been a secret - hardly anybody has noticed - #12 is almost extinct. It's the 3/16" size.

Now, #10-32 is so-called fine thread, 32 turns per inch. That means there are four turns of thread in the 1/8" wall of our mast. #10 coarse thread has three turns in the mast. A 1/4-20 machine screw about 2.5 threads.

If you could find #12-24 machine screws, there'd be three turns. But the tap would have cut deeper threads in the aluminum. #10-32 has rather small not very deep threads. Bigger, coarser, fewer threads of a 1/4" scew is not better altho you think you are using a honkier fastening.
When decommissioning the mast I found the least amount of corrosion in finer thread screws. Many came out as if just installed. Just observation. It may be that tefgel works better in closer, smaller fastenings. Little evidence of colored material on fastenings.

Feel secure?


That's my drift. And my example would be:
Suppose the main halyard got pulled out of the mast sheave and you decided you had to get up the mast and it was the jib halyard you chose to rig your new rock climbing inspired gear to because it was fatter than the spinnaker....


C'pete, How many pounds do you think you had on the one and then the two halyards?

I can't get my brain around that fact that we put mindless trust in a few tiny galvanic screws and yank the hell out of them. We don't ever expect those tacked on plates to never pull off the mast, we just don't give it a thought!

I've decided - or a guy on a cruising site decided me - that there is a correct way to think about it: SCREWS you use for fittings that you might want to take off or renew. Like your flag halyard fairlead.

Use 3/16" stainless POP RIVETS for permanent stuff. Pop rivets come in 1/8", 3/16", 1/4" hole size - with 3'16 closest to the grip lengths we need. In isolating the alloys I'd use LifeSeal also and glue stainless plates to the mast. Redundancy reduces paranoia.
If you use structural Q-rivets that leave tidy nubs inside the mast and a piece of the mandrel in the rivet to make it waterproof you can get an amazing 1650lbs shear strength and 1300lbs of tensile PER 3/16" rivet. (according to McMasterCarr for their 18-8 domed High-Strength Blind Rivets pg3220)
Don't know what a #10 screw has but it can't compare, surely...
Q-rivets come in 304 only, no marine version. And stainless 3/16" pop rivets require a $100 blind rivet tool to set them.


338's Ballenger masthead spinnaker bail has three 1/4" hexbolts holding a more chunky bail than your catalog sample. It's mounted to the narrow bridge top. Most of the masthead is welded construction so it appears pretty strong. The bail is 5/16" rod and your anchor and its foul probably wouldn't have bent it.:rolleyes:
Maybe I lucked out on the fitting?

Now, would I rig my jubangers and prusics to a bar-taut spinnaker halyard and trust this bail with my life?.......:eek::eek:

[ebb]

There's been traffic to this thread, so I'll loop it a bit more here.

I'm going to use the repair plate to weld a 5/16" s.s. rod bail to... for the foresail halyard. I don't know what size rivets I will be using. Most of the ones I drilled out on the mast were 1/4" hollow ones. The ones that break off a piece of the mandrel inside are expensive - especially in the 3/16" and 1/4" sizes.

I ordered the largest manual rivet setter from McMasterCarr. Catalog price $ 96.92. The only manual tool that will set 1/4" s.s. rivets.
It's a huge mutha.
Turns out the tool is the well known Marson Big Daddy Riveter #39031 (made in Taiwan). The thing certainly is nicely made.
Jamestown has the exact same riverter for $161.37.

What's THAT all about?