30mm GRP block/pad

[Yellow Ballad]

Silly question, I have some midships cleats I'll be fitting at some point but I need to raise them up to get over the built in toe rail. I know people make GRP backing pads (which I'll probably do if this works) but would a solid GRP block be ok to mount the cleat on? I was thinking laying it up on a piece of glass and building it up with CSM and polyester in 5mm sessions to desired thickness and then cutting and shaping before fitting in place with epoxy and flocoat. I'm guessing they would be roughly 100x50x30 mm.

What are peoples thoughts? Recommendations on glass weight Or does it not make a difference? What would be best for cutting 30mm? I have a band saw but it has a 6tpi blade so I'm guessing I would need a finer blade. Shaping would a router work with grp, finishing with emery cloth? Or is it hacksaw, file and elbow grease. I'm guessing if I could de 30mm I could go to 50mm?

I know I could use a hardwood block but I would like to make it look "factory" so to speak.

Many thanks in advance.

 

[LoneHort]

Hi Tom,
If it was me I would get some HDPE and after shaping it bond in place with something like CT1.
Will look a lot better than trying to build up layers of PResin,CSM etc.
I had a quick google and this for example is one supplier in the UK.
https://www.theplasticshop.co.uk/polyethylene-sheet-hdpe-10mm-12mm-15mm-20mm-25mm-30mm-thick.html

 

[Norman_E]

If you are going to raise mooring cleats you need to think about the increased leverage of any sideways pull, measured at deck level. You need both the raising pad and the backing pad below deck to be wide enough to resist the leverage without risk of damage to the deck. If the deck is balsa or foam cored then the core needs to be solid hardwood over the full area of the backing pad.

 

[jwilson]

Rather than laying up on glass and cutting/shaping afterwards could you find a suitable sized/shaped plastic food or packaging box to use as a mould to give the smooth sides and eventual top of the GRP moulding? I used a large yogurt pot lid to make a similar smooth moulding for a round external switch panel.

Agree with Lonehort about cored deck and backing pads etc., but not a fan of HDPE as a material.

 

[Neeves]

Stupid question I know,

But why do you need to raise the cleats?

If the issue is wear of the toerails on the mooring lines, simply protect the lines, dyneema sleeves or more crude - plastic hosepipes. As Norman points out you are, apparently, going to introduce increased stress to the deck, which you will need to accommodate - and (as I'm lazy) protecting the mooring lines seems, well, easier.

But you may have some other need for raised cleats.

Introducing 'more' flush cleats will not negate Norman's comments - you will still need to ensure the deck is sufficiently robust, drill our the balsa or foam (if there is any) and fill with resin to take the intended loads and back with stainless plate or hardwood.

Jonathan

 

[lw395]

If you are going to raise mooring cleats you need to think about the increased leverage of any sideways pull, measured at deck level. You need both the raising pad and the backing pad below deck to be wide enough to resist the leverage without risk of damage to the deck. If the deck is balsa or foam cored then the core needs to be solid hardwood over the full area of the backing pad.

I would hollow out the core around the bolt holes and fill with epoxy and glass.
Drill a small hole, just through the top skin of deck, use a sharpened allen key in a power drill to pulverise the balsa around a 1in radius. Hoover out, poke in lots of chopped glass, squirt in warm epoxy with a syringe. Mask the deck first. Warming with hot air gun helps thin the epoxy and it sets quicker.
Shaping GRP, I'd use a hacksaw, file, belt sander.
But it's not hard to knock up a simple mould and make the GRP roughly the right size.
A 30mm thick block may get hot if you mould it in one go.

For preference, I'd have gone for 4-hole cleats to reduce the leverage issues. Or you might fix the block to the toe rail?

 

[Graham_Wright]

Why not protect the toe rail with some stainless capping?

If you go for HDPE, try Plastim in Gloucester for some offcuts. You won't want to buy a sheet!

 

[Yellow Ballad]

Thanks for the replies, here's a couple of pics of the toe rail, it's easier to see then describe.

and these are the cleats, they are offset, my thought was to keep the top part close or over to toe rail.

Luckily the core doesn't start till about 50mm inwards of the tow rail, I can bolt through the solid GRP hull/deck joint. The toe rail is tapered so my thought was to incorporate this into the block to help with sideways pull if that makes sense. I can have a decent backing pad to help with twist below and the toe rail itself above the deck. The tow rail height is about 50mm but I only really need to raise the pad 30mm to get the lines over the top the cleat itself is about the same height as the rail but being offset I need to raise it up to sit over the top. I may decide that raiding the pad up to the top of the rail may make it look better. I would like to do the same with the forward fairleads to fit bigger ones, these are fine for marinas but on the fore aft shore moorings we run some pretty big lines and they don't fit in the current ones.

I did think I could make a mould by taking a cast of the area, or making a plug out of blue foam? What are peoples thoughts? Make a balsa/foam/softwood plug to make a mould from and then gel coat and pour in 1cm long CSM and laminating resin in 5 pours? I just though by the time I had done this I could have laid up some glass cut it and and shaped it, but I'm was just unsure how CSM would cope with being "worked" or if bi cloth would be better.

I'm all ears.

Edit, You should be able to make out the stanchion base "pad" I would like to do something that looks similar but just wider.

 

[Jokani]

Silly question, I have some midships cleats I'll be fitting at some point but I need to raise them up to get over the built in toe rail.

You toe rail seems similar to my Centaur, this was my solution:

It may not be aesthetically as pleasing as you are after, but it was relatively simple, and seems exceptionally strong.

More pictures here Centaur Centre Cleats.

 

[Yellow Ballad]

They're certainly not ugly, food for thought.