Winch backing plates

[Blitz]

I plan to upgrade some winches on my boat and wondered what materials are acceptable as backing plates for say a size Lewmar 48 self tailing winch. The underneath of the winch would be in a combing box and be partially exposed to the weather.

I was wondering if everyone was using stainless steel, teak or some other materials. Has anyone used fiberglass?, how thick?

I was also wondering where is the easiest place to purchase these materials. MacMaster or ?

Thanks,

Neal

 

[Steve Dion]

Neal:

Plywood should be an acceptable material. You can either fiberglass it or epoxy the material (just to prevent moisture). Then you would through bolt the winch in place and use large stainless steel washers. If the plywood is larger than the winch it will help distribute the load.

 

[Ross]

Plywood, White oak, Black locust, Black walnut, vertical grain Doug Fir, Lay up 3/4 inch of fiberglass and resin any of these will serve, make them a large as will fit the space, seal them against moisture.

 

[sailingdog]

1/4" aluminum would work well too, and might be easier to fit, given the clearances you'd need for a fiberglass or wood backing plate.

 

[Maine Sail]

As said any of the above will work. I like G-10.. Be sure to check for soft cores (balsa / foam) as they don't like compressive loads and a soft core should be potted with epoxy to prevent any compression and resulting movement. An ST 48 will have substantial loads. Most builders used marine ply under winch locations but not all...

 

[Blitz]

G-10

As said any of the above will work. I like G-10.. Be sure to check for soft cores (balsa / foam) as they don't like compressive loads and a soft core should be potted with epoxy to prevent any compression and resulting movement. An ST 48 will have substantial loads. Most builders used marine ply under winch locations but not all...

I want to thank all those who replied, opened my eyes to the many options.

What thickness of plywood is normally used?

G-10 or Aluminum sounds good since they shouldn't absorb water, and don't need to apply epoxy. Maine Sail - what thickness of G-10 would you use? 1/4" or thicker? (By the way, your site has provided me with the proper guidance previously for thru deck fittings in regards to potting and epoxy - Thanks)

Thanks again

 

[newly anonymous]

wait wait wait

One of the first things I'd look at, were I a potential buyer of that boat a few years from now, would be how you'd backed those winches.

Okay, the deck on a Seidelmann 34 is hand-laid fiberglass over an end-grain balsa core. I would assume the coamings are the same. The coaming pockets are lined with solid teak. Given that info, I'd be hard pressed to make backing plates out of anything less than 1/4" teak plates backed by fender washers.

Keep it nice so that when it comes time to sell it, people aren't wondering why you switched to ply when you've got a that amazing solid teak everywhere else on the boat, including the interior.

Lewmar 48 primaries on a Seidelmann 34? Seems like a bit of overkill.

 

[Blitz]

Winch size / materials website

I will probably go with Lewmar 44 or 46 self tailing winches (Defender has 46's but no 44's). 48s would be the maximum size based on the Lewmar selection guide.

It will be a nice installation even if you won't see it (unless you are inspecting it), but most of all I want it to be structurally correct.

If any one knows of a good web site to get small pieces of teak, aluminum or G-10 - I would appreciate it. Thanks for the replies.

 

[Ross]

G-10 Appears to be the modern equivilant of the old phenolic-linin laminate board. I have several blocks make from that and I have seen winches in it also. If I were looking for some in New Jersey I would go around to the small machine shops with my hat in my hand and explain what I was looking for. I would probably come home with what I wanted for no cost.

 

[rardiH36]

If you can find it wide enough, you might want to consider Hardwood deck lumber such as IPE which should be available at you local lumber store. Stuff is stiff and rock solid (but readily cutable and drillible with standard power tools) and is full of oils like teak that resist rotting. The standard width is 5.5" which was wide enough for the backing plates for my Harken ST44 winch installation last year. I had some pieces on hand (left over from an electric guitar body project). The local lumber store had let me cut 4' from a 12' foot length, and the remaining 8' length was transferred from the 12' bin to the 8' bin. On the West Coast IPE is running about $3.00 per foot.

Re the winch installation be sure to note in the instructionns that the winches should be oriented so that the side which has the internal gears is on the side that has the load from the sheet. I mention because although I picked this up on the intructions and got it correct for the first install on the starboard side, my thought process fouled up for the port side. I figured that since the gears were facing outside on the starboard, then face them outside for the port side as well. Only occured after I had drilled the holes for the port side that since the sheet is wound clockwise on both sides, that the port side gear orientation needs to be on the inside. Unfortunately two of the holes wouldn't line up when the winch base was roated ... so lots of extra work. I even called Harken to ask how important the orientation was. The customer service engineer confirmed that if not oriented right, the service life of the winch likely would be shortened.

 

[sailingseadragon]

Neal,

I replaced my old Lewmar 42's with Lewmar self tailing 48's three (3) seasons ago.. I went with 1/8" stainless steel backing plates. At the time the plates cost me about $30 each from a local machine shop without the holes... I drilled the holes (not an easy task). I do not know if this was good price or not...

http://www.sailingseadragon.com/Winches.htm

They have served me well and are probably overkill.
Garner

 

[Ron20324]

You might try a heating/cooling company that cuts large holes for air ducts, or a machine shop that cuts holes and tosses the rounds into a scrap bin. If the underside of the bolts are in a cabin, you might put an eye nut on one bolt or an eye strap across two bolts to have a place to hang things. Dual-duty, you know.

 

[sailingdog]

The scrap from air ducts is generally too light a metal to work as a proper backing plate IMHO.

 

[Ron20324]

SD, I was not thinking "regular" air ducts. I didn't think I would have to spell it out that thickness should be considered. Maybe you should see some commercial applications or in-shop construction.

 

[Ross]

If you can put the piece in a vise and bend it or break it with a 12 inch crescent wrench it is too light.

 

[sailingdog]

Ron—

The other problem with scraps from an "air duct" is most are galvanized mild steel, rather than aluminum or stainless steel. In a marine environment, galvanized steel with cut, ungalvanized edges isn't all that durable a material.

 

[Steve Dion]

If you decide to go with plywood, you should probably use 1/2". Most of the time you can find some scrap around the marina yards.

If you go with plate metal, you can also attach the winch by drilling and taping the metal.

 

[Blitz]

If you decide to go with plywood, you should probably use 1/2". Most of the time you can find some scrap around the marina yards.

If you go with plate metal, you can also attach the winch by drilling and taping the metal.

Thanks, I'll most likely go with Stainless Steel.

 

[Hermit Scott]

I would go with aluminium instead of stainless if you have to machine it yourself. It is difficult to drill holes in. You will have to keep sharpening your bits, cobolt bits.
If you wanted to be fancy about it you could have a machine shop cut circles out of 1/4" al. Then drill it yourself, since you don't see the holes. Then have it anodized.
In my personal opinion that would look better than stainless.
Let me be clear on that Stainless in very very difficult to drill!

 

[RickT671]

I plan to upgrade some winches on my boat and wondered what materials are acceptable as backing plates for say a size Lewmar 48 self tailing winch. The underneath of the winch would be in a combing box and be partially exposed to the weather.

I was wondering if everyone was using stainless steel, teak or some other materials. Has anyone used fiberglass?, how thick?

I was also wondering where is the easiest place to purchase these materials. MacMaster or ?

Thanks,

Neal

I have had the best success drilling holes in stainless steel with titanium drill bits.