fitting a coachroof winch

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Laundryman

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My Oceanis 321 came with only one coachroof winch. On the port side there is a moulding in the roof showing I presume the position of the port winch if fitted. The stbd winch doesn't appear to have any kind of backing plate as far as I can see. The bolts come through the grp and are secured with nuts. Is it likely to be embedded in the grp and if so, is there likely to be one embedded on the port side. If there is, will it be pre drilled with the bolt holes and/or threaded and how will I know where the holes are? Ive made myself a backing plate to fit underside the roof so in a way I am hoping that its just a thick layer of grp. I don't see how I can find the bolt holes in an embedded plate without drilling loads of small holes. Advice please Thanks Alan
 
Laundryman said:
My Oceanis 321 came with only one coachroof winch. On the port side there is a moulding in the roof showing I presume the position of the port winch if fitted. The stbd winch doesn't appear to have any kind of backing plate as far as I can see. The bolts come through the grp and are secured with nuts. Is it likely to be embedded in the grp and if so, is there likely to be one embedded on the port side. If there is, will it be pre drilled with the bolt holes and/or threaded and how will I know where the holes are? Ive made myself a backing plate to fit underside the roof so in a way I am hoping that its just a thick layer of grp. I don't see how I can find the bolt holes in an embedded plate without drilling loads of small holes. Advice please Thanks Alan
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Hi Alan,
It's a pretty safe bet the Port side has a lump of ply classed in. You could offer up the backing plate you have and mark it on the underside of the deck and use a small drill to see what material comes out once you get through the glass.

If is ply then you will have to drill the bolt holes oversize by about 15 to 20 mm, then tape over the bottom and fill the void with a mix of Epoxy resin and Micro-Fibres, just wet the holes with resin before you start mixing in the fibres.

After 24 hours it should have cured depending on temperature and moisture, so you drill out the holes and mount your winch.

Tip: Make sure the backing plate has wall rounded edges and corners.

Good luck and fair winds. :)
 
oldsaltoz said:
Hi Alan,
It's a pretty safe bet the Port side has a lump of ply classed in. You could offer up the backing plate you have and mark it on the underside of the deck and use a small drill to see what material comes out once you get through the glass.

If is ply then you will have to drill the bolt holes oversize by about 15 to 20 mm, then tape over the bottom and fill the void with a mix of Epoxy resin and Micro-Fibres, just wet the holes with resin before you start mixing in the fibres.

After 24 hours it should have cured depending on temperature and moisture, so you drill out the holes and mount your winch.

Tip: Make sure the backing plate has wall rounded edges and corners.

Good luck and fair winds. :)
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That just seems like a lot of unnecessary work, if the inbuilt ply packer is adequate for the existing winch why is the same set up not fine for the new one?
 
johnphilip said:
That just seems like a lot of unnecessary work, if the inbuilt ply packer is adequate for the existing winch why is the same set up not fine for the new one?
Click to expand...

oso is advocating best practice which is to prevent water getting into the ply. The original builder may or may not have done the same thing.

He's not suggesting any increase in strength.
 
Laundryman said:
My Oceanis 321 came with only one coachroof winch. On the port side there is a moulding in the roof showing I presume the position of the port winch if fitted. The stbd winch doesn't appear to have any kind of backing plate as far as I can see. The bolts come through the grp and are secured with nuts. Is it likely to be embedded in the grp and if so, is there likely to be one embedded on the port side. If there is, will it be pre drilled with the bolt holes and/or threaded and how will I know where the holes are? Ive made myself a backing plate to fit underside the roof so in a way I am hoping that its just a thick layer of grp. I don't see how I can find the bolt holes in an embedded plate without drilling loads of small holes. Advice please Thanks Alan
Click to expand...
It can't usefully have an embedded threaded plate unless the builder declares what size and brand of winch it is for, and how to locate the holes. Even then the plate would then inhibit your choice of another winch.

All that would be additional unnecessary expense to "facilitate" fitting a winch accessory he didn't sell,
Position your winch, drill pilot holes, see what you get , then drill & seal it if need be as in oldsaltoz's post.
 
The 15 to 20 mm oversized holes filled with epoxy is not just a ply sealer, it is something solid to bolt down onto, otherwise the plywood core material would crush.

Plank
 
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boguing said:
oso is advocating best practice which is to prevent water getting into the ply. The original builder may or may not have done the same thing.

He's not suggesting any increase in strength.
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Oso may do it his way, I would use mastic and go sailing.
 
For what it's worth, the coachroof winches on my Maxi 34 are simply bolted through a single layer of solid fibreglass, with ordinary washers under the nuts on the inside. No backing plate either inside the layup or underneath.

Pete
 
Two comments,

I think that over drilling by 15 to 20mm for the purposes of potting the holes is rather excessive. Even if large washers were used beneath the deck, a good proportion of their diameter would be supported by the resin plug alone, which is only held into the deck by its adhesive properties. If that adhesion fails, you could pull the resin plugs, bolts, washers and nuts right through the deck due to them being largely unsupported by the layup around them. I'd drill about 50% larger than the diameter of the fixings, then pot the holes and drill to the correct size.

Second, when marking for drilling the holes and mounting the winch, enusre it is in the correct orientation. Many winches are designed to have the line arrive onto the winch at a specific point on their circumference, usually where the secondary gear shaft is located or at a point marked by a sticker or some such.
 
The OP is installing a backing plate so no chance of a pull through.

The oversize holes and resin with Micro-Fibres helps to prevent water getting into the ply and rotting it.

The plug also takes the compression of the bolts so the ply (of unknown quality) is not crushed.


Good luck and fair winds. :)
 
Fair point on the backing plate. I'd lost sight of the mention that one is definitely to be used while reading the subsequent posts.

I'd still not drill 15 to 20mm oversize though. A winch suitable for a 32 footer probably has M6 fixings, so you'd be drilling holes between 21 and 26mm, which could put the OD of the drilled hole outside the diameter of the mounting base. If that we're the case, it means that the interface between the plug and surrounding laminate would not be protected by being covered by the base and sealant applied beneath it, resulting in a potential ingress point for water into the core. It might even put the OD of the plugs outside the diameter of the drum itself, which could lead to the same problems as above and would also look pretty horrible on the visible deck side.

I'd also be a bit worried that drilling a circle of one inch holes in an area smaller than the palm of your hand doesn't leave a great deal of continuous structure remaining beneath the winch. You'd have taken as much out as you'd left in.

I'd drill the correct sized holed first to see what's in there. Then:

If it's solid GRP, leave it at that and bed the winch down.

If foam cored, rout out the foam to a reasonable diameter from between the internal and external laminates, pot the holes/voids, then re-drill.

If ply, over-drill by 50% (so a 9 or 10mm hole for an M6 fixing, which gives a tube with a 2mm wall thickness when re-drilled), pot the holes, the re-drill.

If you're tightening the fixing bolts sufficiently to crush the area of a winch base and its backer into a deck which contains even a poor quality ply pad due to the absence of 1" diameter epoxy pillars to prevent it, I'd suggest some tables and a torque wrench might be in order. Less than 10Nm for an A4-70 M6 fastener off the top of my head.
 
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Hanse bed an aluminium plate into the lay up
I suggest that you drill the first holes undersize so that if there is metal in place then you can tap it
I am surprised they would fit ply as I would have thought the ply to be weaker than the equivalent GRP & more expensive to install
material being cheaper but labour higher & fiddly

The idea of drilling bigger holes is one promoted by the Gudgeon Brothers with the West system
using their high performance filler ( forgotten the ref No.) it spreads the load of the fixing onto a greater area ( the circumfrence of the hole being greater)
 
Just to report back, the winch is now fitted. There is indeed a plywood pad embedded in the grp of the coach roof but the biggest surprise ( for me at least ) , was the thickness of the coachroof itself. I had bought m6 x 40 bolts in readiness but the roof itself is 50mm thick. Who would have thought it of a French plastic awb. Thanks for the advice. Alan
 
Laundryman said:
Just to report back, the winch is now fitted. There is indeed a plywood pad embedded in the grp of the coach roof but the biggest surprise ( for me at least ) , was the thickness of the coachroof itself. I had bought m6 x 40 bolts in readiness but the roof itself is 50mm thick. Who would have thought it of a French plastic awb. Thanks for the advice. Alan
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Never underestimate boatbuilders, I had the exact same surprise on my Vivacity which I was certain was only 5mm thick where I drilled on the side deck but it turned out to be 20mm with ply in the laminate. Gives a lot of confidence in the boat though!
 
Laundryman said:
Just to report back, the winch is now fitted. There is indeed a plywood pad embedded in the grp of the coach roof but the biggest surprise ( for me at least ) , was the thickness of the coachroof itself. I had bought m6 x 40 bolts in readiness but the roof itself is 50mm thick. Who would have thought it of a French plastic awb. Thanks for the advice. Alan
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Interesting
How did you get on removing and refitting the internal coach roof lining/ finishing
I too am considering retro fitting a winch and clutch fitting and a main sheet traveller to the coach roof of a Oceanis 311
 
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