Ply or grp for cleat backing plates

[George DuBose]

HDPE is what some cutting boards are made of. It is moderately flexible, doesn't rot or corrode, easily sawed and sanded, can be purchased in a variety of thicknesses and isn't expensive.

Epoxy, especially G-Flex will adhere to HDPE if one oxidized the HDPE surface with a flame first.

Sheet fiberglass is brittle, aluminum corrodes, wood rots and stainless is expensive and not easy to work.

[Matt Johnson]

Originally Posted by thinwater

The ONLY time you need G-10 is if threading or machining is critical.

And I have test broken sheets and pulled out threads to prove the above. IMO the importance of G-10 has become an internet forum exaggeration; it is very good but unnecessary, rather like using all-titanium hardware.

+1 Another example of everyone being told epoxy is the best/only choice for a polyester boat.

If you're conscientious enough to be asking this question in the first place, you're probably going to overbuild the backing plates whether you choose FRP or G10.

Spend the same amount you were comfortable spending on G10 and just buy a larger sheet of FRP. Even on an aluminum boat I keep a few sqft of frp for different uses. It's great stuff to have lying around!

Matt

[Matt Johnson]

Originally Posted by George DuBose

HDPE is what some cutting boards are made of. It is moderately flexible

-which is the exact opposite of what you want in a backing plate.

Matt

[GILow]

Now I'm nervous. Mine are stainless steel. Nobody mentioned it, should I be worried?

[transmitterdan]

Originally Posted by GILow

Now I'm nervous. Mine are stainless steel. Nobody mentioned it, should I be worried?

Quick, switch them out with titanium plates...before your boat sinks....

[GILow]

Originally Posted by transmitterdan

Quick, switch them out with titanium plates...before your boat sinks....

Just what I was thinking. But then I thought maybe Vibranium?

[bgallinger]

My Hunter 340 uses 1/4" thick aluminum plates glassed in. I'm so pleased Hunter goes the extra mile!

[Pugcat]

Wow, thanks very much for all the responses, this forum never disappoints. Just to add a bit more info the boat is an old prout Snowgoose 35 so the deck isn’t cored, just thick grp. I’m liking the idea of using thickened epoxy as a “leveller” between whatever the backing plate ends up being (I’m thinking grp sheet) to spread the load evenly. Surely just cranking down on some big washers or metal plate without levelling the surface would risk point loading wouldn’t it?

Also, and very much putting the cart before the horse here as we’ll be coastal pottering for a couple of years yet, if these cleats were to be used for attaching a sea anchor how big should the backers be? As said it’s a non issue right now but if I do a beautiful job of making solid, epoxied in place backers now they would be a nightmare to replace with bigger ones later.

Thanks again for all responses

[flyingfin]

Go to the local scrap metal yard and find some used aluminum channel or angle, find a decent thickness for the application and cut to length.

[frozenhawaiian]

if you can get your hands on it where you are go for G10. failing that I'd go stainless blacking plates over fiberglas or ply.

[Island Time O25]

Based on 12 years of ownership of 5 boats my own preference would be in that order:

1. G10
2. SS plate
3. Aluminum plate
4. Epoxy enclosed marine or treated ply or solid wood

Each has its pluses and minuses the question will always be which minuses you can live with and which pluses you cannot live without. Since one is not buying 8x4 sheets of any of it the few extra $$ one will spend on few scraps needed will go a long way, especially considering that you will be all set for the time you own the boat and then some.

I had seen what 20-30 year alluminum and epoxy enclosed ply backing plates can look like and that's why they are not my first choice. But given the fact that they did last 20-30 years they are still a choice.

[s/v Jedi]

We're talking about mooring cleats attached to the deck. High forces and we've seen the pictures of ripped out cleats.

Hard spots is not a myth and I have never seen any metal backing plates that have been tapered. G10 is pretty good but FRP or DIY laminate is great as well. Even HDPE sheet will work if it's thick enough. All you want to something that is crush resistant and load spreading without creating hard spots

[admiralslater]

Originally Posted by billknny

It's unanimous! When does that EVER happen here?

Can it be used as a weapon? Sorry I could not resist

[Emptynest]

On my Catalina 30 78 there were only washers so I had stainless steel 1/4 inch plates made then drilled for cleat holes works great

[s/v Jedi]

Originally Posted by Emptynest

On my Catalina 30 78 there were only washers so I had stainless steel 1/4 inch plates made then drilled for cleat holes works great

How do you know it works great? Did you have a storm where your neighbors got their cleats ripped out the deck while you had no damage?

Or do you mean that they fit when you installed them?