Mounting New Cleats - hollow space!

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Perplexed

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My yacht is poorly equiped with cleats. So I want to put an additional cleat amidships on either side.

The plan is good....but the application has caused problems, and for this I ask for your help, please.

My hull is twin shells, with foam filling between - but not where the cleats are to be!! Which I found when I drilled my first hole!
There is just a hollow space, about 50mm deep. Drilling further goes down against something very solid, and if I forced the issue I am certain my hole will not come through into the cabin, so I am unable to fit a backing plate and bolt through the cabin deckhead.

So, it seems as though I have to find way to fix something inside the empty, hollow space between the layers. I have epoxy, but there is nothing in the hollow space to contain it, or hold it.

Has anyone suggestions how to get around my problems, please?



 
I may have the wrong end of the stick, but the only way I can picture your problem is that the void you're discussing is outside both the hull and deck liners?

If that's the case, how about injecting a little two part foam in there, and then when it's cured use a rotating rod with a 90 degree bend in it to shear out the foam leaving a cylindrical void which you can then fill with glass/epoxy filler and a suitable thread insert?
 
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I think you need to make up a stainless steel plate with captive nuts that fit the cleat bolts. You will then need to cut a large enough hole alongside the cleat position so that your plate can be slid in. Then remake the deck with epoxy and glass.

Spring toggles are the simple answer but I have never seen any in stainless steel and they are universally described as being for light loads. E.G. Spring Toggles
 
vyv_cox said:
I think you need to make up a stainless steel plate with captive nuts that fit the cleat bolts. You will then need to cut a large enough hole alongside the cleat position so that your plate can be slid in. Then remake the deck with epoxy and glass.

Spring toggles are the simple answer but I have never seen any in stainless steel and they are universally described as being for light loads. E.G. Spring Toggles
Click to expand...

If I'm picturing it right Vyv, it could be easier to cut away the liners and make simple cover panels?
 
If there's only the single load-bearing skin of the deck to take the forces from the cleat, there may be no point doing anything elaborate.
Traditional solutions are based on getting some strength from the lower skin of a sandwich deck.
How thick is the deck skin?
How strong do the cleats need to be?

Maybe all that's needed is rivnuts or self tappers?
Then if you do rip the cleat out the damage won't be huge....
I hesitate to suggest epoxying the cleat to the deck....
but actually mounting the cleat on a wooden pad glues and screwed down might be valid?
 
I had the same problem on my Beneteau motor boat. I simply bought spring cleats and stainless self tapping screws . I did worry at first that they might pull out, but the loading from springs is horizontal and not that great. They are still in place ten years later. I did use pretty substantial self tappers.
 
alancollins said:
I had the same problem on my Beneteau motor boat. I simply bought spring cleats and stainless self tapping screws . I did worry at first that they might pull out, but the loading from springs is horizontal and not that great. They are still in place ten years later. I did use pretty substantial self tappers.
Click to expand...
Wow. Rather you than me. I would not risk that approach.
One bumpy night in Guernsey guest harbour the retractable centre mooring cleat on a new Moody 45DS broke due the forces involved.
S/S backing plates and bolts would be the only solution I would like.
The OPs specific challenge is probably the unique "unsinkable" construction of Etap boats. Is there an owners association to fund out how others have done this for this specific boat type?
 
dunedin said:
Wow. Rather you than me. I would not risk that approach.
One bumpy night in Guernsey guest harbour the retractable centre mooring cleat on a new Moody 45DS broke due the forces involved.
S/S backing plates and bolts would be the only solution I would like.
The OPs specific challenge is probably the unique "unsinkable" construction of Etap boats. Is there an owners association to fund out how others have done this for this specific boat type?
Click to expand...
But the SS plates solution will still only be as strong as the single skin of the deck.
That might be strong enough, or not.
So it ultimately depends on what you want the cleat for.
If it's to hold the boat alongside while sorting the bow and stern lines, that's maybe less onerous than mooring badly in a rough marina through a storm.
I'd rather have some self tappers pull out of my deck than an ss plate take a square foot of deck with it.
If you're looking for ultimate strength, maybe the cleat wants to be mounted on a stronger part of the boat.

Maybe fit a plastic cleat, so if anything breaks, it's only four quid?
 
lw395 said:
But the SS plates solution will still only be as strong as the single skin of the deck.
That might be strong enough, or not.
Click to expand...

I cannot speak for Etaps but the decks and hulls on Sadlers are the same thickness as those on any conventional boat. The inner skin is very thin: I cut mine with a knife when fitting the inner pads for my Yacht Legs.
 
I like Etaps a lot but you may have hit a snag. The toerail fittings are pretty well fastened, and I suspect that most owners just use these as fastening points - the "standard forward and aft "cleats" are usually just short toerail sections. Now you've drilled a hole and if you really can't get internal access I'd go with the previous suggestion of ".... injecting a little two part foam in there, and then when it's cured use a rotating rod with a 90 degree bend in it to shear out the foam leaving a cylindrical void which you can then fill with glass/epoxy filler and a suitable thread insert". If you can get 2 inches of epoxy in there you could just tap it, or put greased bolts in as it sets to form threads.

Ideally a mooring cleat should in extremis be strong enough to lift the whole boat (or at least half of it) by at any angle, but most are not, and for normal spring usage you ought to be able to get an acceptable result as described by "Occasional".
 
vyv_cox said:
I cannot speak for Etaps but the decks and hulls on Sadlers are the same thickness as those on any conventional boat. The inner skin is very thin: I cut mine with a knife when fitting the inner pads for my Yacht Legs.
Click to expand...
I regard a 'conventional' deck as having a balsa or ply core and a substantial skin top and bottom. At least in the stressed areas.
 
lw395 said:
I regard a 'conventional' deck as having a balsa or ply core and a substantial skin top and bottom. At least in the stressed areas.
Click to expand...
True, but they usually become single skin at the deck edge, which is where we're looking I think. Etap do make beautifully detailed mouldings and I'd expect the liner to be very thin and easy to cut as noted above.
 
Just spit balling:

  • Fill the cavity with expansion foam. Strength not important.
  • Open up the spaces under the bolt holes with a bent nail or something similar, something like you would to seal the hole, but a lot more area. Also deeper, about 2 cm.
  • Fill with epoxy and then stuff in little strips of fiberglass cloth using a wooden skewer. Just keep stuffing them in there until no more will fit. It will be more than you think. Top off with epoxy.
  • Drill and tap.
The fiberglass will reinforce the epoxy plug. I've done this and it will be stronger than the skin. How strong depends on how big the plugs are.

But yeah, the skins are just skins.

Another possibility, which takes finish work, is to bond a large fiberglass pad (which you have mounted the cleat to) to the deck . Strength depends on how big you go, but it can be lots. Good finishing can make it look like a factory pad. I've done it for winches and windlasses, and it's a lot more work.
 
Fix a centre cleat to the toerail by bolting a block to it wide enough to allow the cleat to be fixed to the block with recessed heads for the nuts.

Did this in NZ earlier this year.

Bugger trying to work with a void - I would always be worried about strength there.
 
If you want to use the location where you have already drilled a hole then I would not bother with foam but rather just pump fairly thick epoxy into the void via the hole and or an additional hole. The foam was to make a dam for the epoxy. However be careful some foam can expand too much and damage the GRP. Get a large hypodermic syringe. Getting the thickness right will be tricky. The more you pump in the broader the epoxy base so broader the load bearing area on the inside of the top skin and on the bottom skin. You may have to let epoxy harden then add more to get the mound right up under the top skin. Once all is hardened drill and tap screws to take the cleat. I imagine a 6mm tap and screws to match are not expensive and always useful.
 
Perplexed said:
My yacht is poorly equiped with cleats. So I want to put an additional cleat amidships on either side.

The plan is good....but the application has caused problems, and for this I ask for your help, please.

My hull is twin shells, with foam filling between - but not where the cleats are to be!! Which I found when I drilled my first hole!
There is just a hollow space, about 50mm deep. Drilling further goes down against something very solid, and if I forced the issue I am certain my hole will not come through into the cabin, so I am unable to fit a backing plate and bolt through the cabin deckhead.

So, it seems as though I have to find way to fix something inside the empty, hollow space between the layers. I have epoxy, but there is nothing in the hollow space to contain it, or hold it.

Has anyone suggestions how to get around my problems, please?
Click to expand...
Is there an idler's solution? I am wondering if you have 4x bow and stern cleats...and on a 23 footer, doesn't that suffice?

Just curious.
 
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