Backing for clutch hardware

[L124C]

I would like to install a bank of clutches in front of the winch on my coach top. They would serve the Vang, Main sheet and eventually, the Halyard. I want to know if I need to install backing for the new hardware. Currently, the boat has a set of blocks that divert the Main and Vang lines aft. There is no backing for that hardware, or the winch (see pictures). I'm assuming since the hardware has survived for years without backing, none is needed for the new clutch bank. Is this correct? I was also concerned that there was not enough space for the clutches in front of the winch. However, I've seen installations with less space. Thoughts?
Pics:
Winch where new clutches will go
Existing blocks
Bottom of existing blocks
Bottom of existing winch

[cb32863]

Is it just my eyes or is that a crack in your bottom picture? Also, some discoloration in the third one looks like something got through by one of the bolts. I am not an expert as much as some other people here but backing something that is under load makes sense to me. Maybe the clutch doesn't take as much load but a rigger could tell you that more precisely.

[puddinlegs]

L, I'll try to take a picture and post what we've done. In a nutshell, unless your deck is thick and solid structural glass where the hardware is installed (you have a Yankee? 30'?...great boat! And if so, it indeed might be actually built to accommodate the winch load though I'd still use larger washers ), backing for winches, clutches, and high load blocks isn't an option... it's needed. For clutches and high load blocks, we use pre-drilled stainless steel plate, 1/8" if I remember. The winches have wood backing plates. Smaller hardware or pieces with lighter loads, large washers.

[GeorgeB]

Could it be possible that you have backing plates/washers on the other side of the headliner? If the acorn nuts and standard washers are all that are backing the through screws/bolts and you sail SF Bay… The blocks are only taking up a fraction of the load (based on their angle of deflection). The winch is taking the full load and distributing it across it’s five through bolts ( is that a stress crack?) Your clutches will take the same load and distribute it across two bolts (more, if they are ganged together in a bank). I would use fender and lock washers as a minimum and red locktite on the acorn nut.

You have an engineering problem topsides. Clutches are on something like 1 or 1 ˝ inch centers which means you will not have a fairlead through the traveller tower without drilling some extra through holes or elongating the one you have. How is the traveller through bolted to the tower? I have seen two travellers pull completely off their towers so do not under estimate those loads. You will need to make a stand-off pad for your clutches so they maintain their fair leads. You will also be trading the stacked turning block for a three block organizer near the mast.

Something to consider is running the vang seperately to the cockpit and terminating it with a cam cleat. Lines run a little bit slower through a clutch and sometimes when you want to release the vang, you want to release it very, very fast.

[L124C]

[QUOTE=cb32863;644135]Is it just my eyes or is that a crack in your bottom picture? Also, some discoloration in the third one looks like something got through by one of the bolts. QUOTE]
Funny you noticed that. I think it's just a mark, as I would have certainly noticed a crack (which would have answered my first question). I'll double check it though! Normally, I would simply back the stuff. However, head room is an issue (I'd kill for an extra 1/2"!). I spend too much time ricocheting off things as it is. A mere 1/8" would make a difference. The nuts for the winch and new clutches are directly in front of the galley sink. On the other hand, I'd hate to see my winch flying through the air (though...that would give me more head room)!

[olson34]

If your cabin top is the common layer of 1) outer skin, 2) balsa core, 3) inner frp layer, and for your boat a close-fitted molded frp headliner....
I would take a look at doing the usual overbore, epoxy fill, and redrill to seal the core.
Then, IF the headliner is against the cabin top, counterbore from below for a SS barrel nut. Then with a carefully measured bolt after the usual dry fit, you would end with the inside almost flush. Lots less opportunity of mashing your skull into one of those acorn nuts.

L

[BigZ]

Originally Posted by olson34

If your cabin top is the common layer of 1) outer skin, 2) balsa core, 3) inner frp layer, and for your boat a close-fitted molded frp headliner....
I would take a look at doing the usual overbore, epoxy fill, and redrill to seal the core.
Then, IF the headliner is against the cabin top, counterbore from below for a SS barrel nut. Then with a carefully measured bolt after the usual dry fit, you would end with the inside almost flush. Lots less opportunity of mashing your skull into one of those acorn nuts.

L

That's a nice, elegant solution.
I did something similar recently using barrel nuts to secure wood channels over the exposed hardware on newly installed genoa tracks, but didn't consider using them on bolts protruding thru the cabin top. Maybe you've just given me some more winter projects.

[sailingdog]

One thing—don't use red loctite on any of these fasteners... you may eventually need to remove them at some point... and blue loctite is all you will really need.

If your deck is cored, you'll have to pot any fastener holes. Also, making backing plates of 1/4" or 3/8" g10 garolite is a good idea.

[L124C]

Originally Posted by GeorgeB

You have an engineering problem topsides. Clutches are on something like 1 or 1 ˝ inch centers which means you will not have a fairlead through the traveler tower without drilling some extra through holes or elongating the one you have. How is the traveler through bolted to the tower? I have seen two travelers pull completely off their towers so do not under estimate those loads. You will need to make a stand-off pad for your clutches so they maintain their fair leads. You will also be trading the stacked turning block for a three block organizer near the mast.
Something to consider is running the Vang separately to the cockpit and terminating it with a cam cleat. Lines run a little bit slower through a clutch and sometimes when you want to release the Vang, you want to release it very, very fast.

Plenty of good points here (gotta love this forum!). I saw a sister ship that had the Vang run through a clam cleat mounted on the side of the tower. Unfortunately, my boats PO "fortified" the tower and traveler for some reason, which no longer makes sense to me. Originally, the traveler track was through bolted to the towers and a piece of stainless that runs under the Sea Hood. The PO added 3 inches of wood beneath the track and SS braces on the ends. I thought his modification made sense until I pulled it apart. I see a lot of boats with far weaker travelers than the original installation on mine. In any case, I can't mount the clam cleat on the towers (do to the braces). I wasn't aware of the quick release issue with clutches. Given that, and the routing issue (which I had previously considered but conveniently forgot), it seems like I should find a place for a clam cleat.

[L124C]

Originally Posted by olson34

Then, IF the headliner is against the cabin top, counterbore from below for a SS barrel nut. Then with a carefully measured bolt after the usual dry fit, you would end with the inside almost flush. Lots less opportunity of mashing your skull into one of those acorn nuts.
L

I like this idea, and went out and bought the hardware. The funny thing is.. I had to find out what a barrel bolt was. In my trade we've always called them Sex Bollts (for some bizarre reason I've never understood!) Anyway, the only drawback I can see with the system is that if some water penetrates the caulking and flows down into the nut, breaking it loose could be a nightmare, as you no longer have a nut to grab onto. I would have to drill out the stainless screw head (ugh!). Wonder if I should coat the treads with Lanacote or something? Maybe blue locktight would prevent corrosion?
Wait...their Sex Bolts. Maybe KY's the answer!