SailNet Community banner

21 - 35 of 35 Posts

·
Registered
Joined
·
3,777 Posts
Perhaps I used misleading info regarding the fender washers. They would not be used to allow reefing the nuts with a meter long bar...
the purpose is to eliminate the possible splitting of the wood block as they spread the load out. I did not suggest pine as a backing material, I suggested oak or teak...both are more than robust enough for this application.
For what it's worth, I have essentially the same boat with halyard winches that are about half the size of the OP's which are through bolted using oak backing blocks. I installed the oak for appearance. When I assumed ownership 25 years ago there was no backing blocks, only fender washers. Between the 2 installation methods, the sails have been raised many, many times over a period of 40 years. The winches work fine and do not leak.
I think that sometimes the owners of much bigger boats apply the same standards to situations where less is enough. Respectfully submitted.
My point is that bolting washers would have been even better, not that fender washers will not work if the material is firm. I'm quite sure your oak backers are more than enough by 4 times and that they look sharp.

Remember to, that at full load the tension on the bolts is 100% WLL on that winch. I've done the calculations. With a softer substrate, full working load is enough to bend the washers; the photos were taken at the WLL, not BS, as made obvious by the fact that the threads are not showing signs of galling. I've seen them bent on brand new boats in shows. It's really common.
 

·
Registered
Joined
·
3,777 Posts
I just wish they'd sell the extra heavy washers instead of the thin ones that don't do the job they suggest they do. Thin fender washer specs were developed 100 years ago for bolting tin fenders, which is totally different. For that application you want considerable flex.

Bolt depot and others sell them.
 

·
Senior Moment Member
Joined
·
13,282 Posts
The necessity for backing plates is way overstated in general IMO - it's much like anchor sizing - a recommendation for bigger by one person begets bigger yet again by the next person and so on and so on.

For boats under about 10,000 Lbs disp there is little need for them under most hardware. Certainly lifeline stanchions need them but most everything else does just fine with large fender washers, particularly hardware that is loaded primarily in shear like clutches. Core reinforcement like potting bolt holes is much more important than big backing plates.

As an example - my old Columbia 43 had huge multi speed primary winches, mounted on teak caps over solid glass coamings, that had never had anything but plain washers - not even fender washers - on the mounting bolts and there was no sign of any problems or recession after more than 30 years which included substantial offshore sailing.
 

·
Registered
Joined
·
525 Posts
Discussion Starter #25 (Edited)
Hey everyone!

Thanks again to everyone who contributed. I wanted to let you know how it all went:

I mounted a deck winch, 3 line clutch, deck organizer, and traveler.

I went with 1/4" G10 for the bearing plates and 1/4" aluminum backing plates. In hindsite the backing plates could have been 1/8"... would have been easier to work with.

I got a bid for the bearing plates from a plastics fabricator. They wanted like $230 to cut to my specs. After cutting the parts myself, I think they were pretty reasonable. All ok, I learned a lot about cutting G10.

I pre-drilled and countersunk all holes on the drill press at home.

Went with a 1" hole saw to core the bolt holes. Potted with West Systems epoxy (slow cure) thickened with silica. Under the winch and clutch, the inner liner is the core backing, so no cutting and patching. No the case forward under the deck organizer. Had to cut the glass liner, build up the bottom with glass fabric and thickened epoxy.

Learned that a few nuts and bolts shaken around in the silica container breaks it up nicely for mixing. However, the 30 min working time shortens to about ~12 minutes when in direct sunlight on a 70 degree day. Had a batch go exothermic and had to hose it down. Melted my mixing bowl.

Pressed the bearing plates into a bed of thickened epoxy, then after it set, drilled the bolt holes.

Seated the backing plates in Sikaflex 491. Not worried about how ugly the backing plates are. Many more pressing cosmetic issues below. However, the admiral has directed that I do something about the backing under the clutch before she busts her knuckles (first on the backing plate, then on my noggin). That's more or less a quote.

With lines led aft, life is so much better... and with the traveler, windward performance is significantly improved. It's like a different boat.

Pics in no particular order to follow.

No fender washers were harmed during this project.
 

Attachments

·
Registered
Joined
·
3,777 Posts
For what it is worth, you don't need or use both G10 bearing plates and aluminum backing plates. It is one of the other. With the G10 all you need is standard bolting washers (not fender washers--the bolting washers actually better distribute the force the G10).
 

·
Registered
Joined
·
926 Posts
Good job Phil. In one photo it appears that you are sailing with the front hatch wide open, I don't think that is a good idea, very easy to snag a sheet.
 

·
Registered
Joined
·
1,014 Posts
Fender washers should be fine backing for the winch fasteners. Definitely rout out the core, fill with thickened epoxy and redrlll the holes. The epoxy will keep the bolts from compressing the core, if any seal any water leakage. Assume the extra pukas on the clutch are for running the clew reefing lines aft.

FWIW, will sell you a proper sized winch for $25 plus shipping if you can wait till May. Can't remember what the make of the winch is but it's similar to a Lewmar 16 and was a halyard winch on my Sabre 28. Assume you just placed the winch and clutch on the cabin top as a demo. example. A smaller winch will give you a better lead angle for the pukas in the clutch.
 

·
Registered
Joined
·
525 Posts
Discussion Starter #32
Good job Phil. In one photo it appears that you are sailing with the front hatch wide open, I don't think that is a good idea, very easy to snag a sheet.
Thanks. The hatch is often open in mild weather, rarely a problem, never a crisis.


FWIW, will sell you a proper sized winch for $25 plus shipping if you can wait till May. Can't remember what the make of the winch is but it's similar to a Lewmar 16 and was a halyard winch on my Sabre 28. Assume you just placed the winch and clutch on the cabin top as a demo. example. A smaller winch will give you a better lead angle for the pukas in the clutch.
I appreciate the offer. The Lewmar 40 was a hand-me-down so to speak. Cost to me was cleaning the winch and a 12 pack of Heinekin. I'm considering raising the clutch a bit, but not convinced it's worth the effort. Balancing perfect with good enough.
 

·
Registered
Joined
·
1 Posts
I am using G10 backing plates under Lewmar 30 winches - but should they be 1/2" or 1/4" thick G10? What size? I am thinking of 4" diameter circles. I have a cored deck (Newport 30-3 1982) and cabin coachroof. Presumably this is of minimal thickness but I don't know what that would be. Over the years one bolt in each Lewmar winch has compressed into and started to split the deck. Same situation with staunchions. I've heard that 1/2' thick G-10 is used but Northern Yacht Restoration | Equinox, Contessa 26 uses 1/4" thick fibreglass composite material. Thanks for any experience or rules of thumb.
 

·
Registered
Joined
·
3,709 Posts
1/4" will be fine. The thickness only comes into play wrt stiffness of the plate, and 1/4" epoxy/glass is very stiff. What is important for the winch mount is the size of the backing plate being large enough to spread out the load evenly. It should definitely be larger than the base of the winch, and larger is always better.

Mark
 

·
Registered
Joined
·
1,014 Posts
The mounting holes should have some of the core routed out and filled with thickened epoxy. The problem with cored decks is tightening the fasteners too much and crushing the core allowing water to infiltrate. Once you do that fender washers would be adequate as backing though nothing wrong with 3/16"-1/4" plate backing in aluminum or fiberglass.

I've using Anderson 12 self tailing winches for my main and jib halyard and reefing winches. Enough power for me on my 35' boat. Boat originally had Lewmar 40 genoa sheet winches.

Epoxying fastener holes.

If you want to do a permanent fix for any fastener through a cored deck do this.

1. Drill your holes through the outer laminate only. You don't want to go through the interior laminate if you can help it. If you do drill through or dealing with a previously installed fitting and can get at the backside, use duct tape or other seriously sticky tape to seal the hole. Don't even think about using masking tape and you know how I learned that. If there is a liner, best thing is use a suitable hole saw and cut a large enough hole that you can use tape to seal the inner laminate closed. Fill the hole you’ve cut in the liner with trim plugs available from McMaster Carr and others McMaster-Carr

2. Get a Dremel tool with a Dremel 199 bit.
https://www.amazon.com/Dremel-199-High-Speed-Cutter/dp/B00004UDGP/ref=sr_1_1?ie=UTF8&qid=1510623034&sr=8-1&keywords=dremel+1993.
Cut the Dremel bit into the hole at as close to a 90 degree angle as you can. This makes for a very minimal enlargement of the drilled puka to maintain deck integrity and in most cases the fitting will cover any damage to the gelcoat. Once the bit is cut in, raise the tool to vertical and rout out the core. I’ve tried the bent nail, sharpened Allen wrench, etc, without a lot of success and a nearly broken wrist. The Dremel 199 bit works way better, less damage to the gel coat and easy to do for fastener pukas. If you’ve other than just s fastener puka, the other tools might work better for routing larger areas though not for me.

3. Once that's done, vacuum out the hole. Fill a syringe with epoxy resin and fill the hole. This soaks the resin into all the void to be sure the core is completely sealed. Have discovered that West Systems has a very slow catalyst (#209) that will allow you to fill a bunch of pukas without the resin kicking in temps over 80 degrees. Use the regular slow hardener (#206) if temp is much below 80 degrees or the epoxy will take forever to go off. If you need the fast catalyst (#205) it’s too cold to be working and wait for spring.

4. Suck out as much of the resin as you can and mix with a structural filler like West 404. Reinject the thickened epoxy into the puka.

5. After the resin has set redrill the hole. The thickened epoxy makes an incompressible base for the fasteners. Personally believe that most of the leaks into deck core is because the installer puts too much torque on the fastener and compresses the core.

6. Finish by chamfering the edge of the hole with a counter sink bit. The chamfer allows for a thick donut of whatever sealant you use around the fastener shaft. That goes a long way to insuring that the fastener won’t leak again. Whether you decided to do the epoxy thing or not, chamfering the edge of the fastener puka is a must for any hope of a leak free install of any fastener.
 
21 - 35 of 35 Posts
Top