Sealing a windlass chain hole ?

[Boo2]

Hi,

I've just fitted my new windlass and have drilled all the holes through the deck and painted the balsa deck core with thinned epoxy to try to prevent water ingress but I am still a bit unsure how well it will hold up. It occurred to me that in some circumstances the chain might rub the balsa core and wear through the thin epoxy coat. Would it be an idea to further seal the chain hole in the deck with a thin layer of silicon ? Or am I worrying unnecessarily ? What have other people here done about this issue ?

Thanks,

Boo2

 

[coopec]

Hi,

I've just fitted my new windlass and have drilled all the holes through the deck and painted the balsa deck core with thinned epoxy to try to prevent water ingress but I am still a bit unsure how well it will hold up. It occurred to me that in some circumstances the chain might rub the balsa core and wear through the thin epoxy coat.

Boo2

I don't follow. If you bolted the anchor winch onto a plywood insert into your deck how could the chain wear through the balsa core? If it worries you why not us a piece of ply strip as a sacrificial "wear plate" between the anchor and the bow roller?

Maybe this clip will help?

https://www.youtube.com/watch?v=JGNGMqkWTaE

 

[john_morris_uk]

I don't follow. If you bolted the anchor winch onto a plywood insert into your deck how could the chain wear through the balsa core? If it worries you why not us a piece of ply strip as a sacrificial "wear plate" between the anchor and the bow roller?

Maybe this clip will help?

https://www.youtube.com/watch?v=JGNGMqkWTaE

Is that you?

 

[Poignard]

Rather than simply painting the exposed edge of the balsa core with epoxy it is better to cut it back between the skins (an Allen key in a power drill will quickly do this). Then fill the void with epoxy and drill for the mounting bolts.

 

[NormanS]

How would it do to glass in a bit of tube of adequate size and material, through the deck, to act as a fairlead for the chain?

 

[john_morris_uk]

Rather than simply painting the exposed edge of the balsa core with epoxy it is better to cut it back between the skins (an Allen key in a power drill will quickly do this). Then fill the void with epoxy and drill for the mounting bolts.

How would it do to glass in a bit of tube of adequate size and material, through the deck, to act as a fairlead for the chain?

Both are excellent suggestions. I was asking who was in the video before I made any remarks about their workmanship!!

 

[Poignard]

This is what I used

http://www.asap-supplies.com/marine...nnections/bronze-threaded-skin-fitting-403127

 

[coopec]

Both are excellent suggestions. I was asking who was in the video before I made any remarks about their workmanship!!

No John, it wasn't me. I was a bit alarmed as it seemed Boo2 had cut a hole through the balsa cored deck and fitted a winch. If he has done that then the balsa would not take the strain of the winch and any tightening of the winch mounting bolts would crush the balsa.

On my yacht I have a 25mm ply-board insert and 2 lengths of s/s angle iron bolted to the bow roller mount and No 1 bulkhead. The chain pipe is 75 mm black irrigation tube (nylon?) bolted to the deck and anchor locker.

 

[nigelmercier]

... it seemed Boo2 had cut a hole through the balsa cored deck and fitted a winch...

Surely not?

 

[coopec]

Mounting hardware on cored decks: Right and wrong ways

Submitted by Matthew on 2012, October 9 - 06:33

Improperly mounted hardware is a constant source of frustration for boat owners. Sometimes it's water leaking in through a bolt hole, sometimes it's rust bleeding onto the deck, sometimes it's a cleat that tears off its mount under load.

Here's how to mount hardware on cored fibreglass decks correctly, so you won't have to deal with it again- and a few examples of why things go wrong otherwise.

http://marine.marsh-design.com/content/mounting-hardware-cored-decks-right-and-wrong-ways

 

[coopec]

Hardware Horrors - why we're our own worst enemy when it comes to drilling, mounting and screwing thing to our boats

View attachment 41087

http://www.captfklanier.com/articles/art22.html

 

[oldsaltoz]

Both are excellent suggestions. I was asking who was in the video before I made any remarks about their workmanship!!

Common practice is to undercut the core as above, paint with an epoxy resin and add Some Micro-Balloons to an epoxy rsin and tape the bottom of the hole, then fill with the mix and let it cure, then re drill the holes to through bolt to your backing plate.

For the cain entry point, treat as above and push a bit of stainless steel tubing through leaving the top a few mm above deck to reduce water entry.

You can cut a 'C' shaped bit of bread board to slide over the chain link and sit flat on the stainless tube to further flow into the locker.

Good luck and fair winds.

 

[Boo2]

Just to answer some of the points above :

I have drilled the fixing screw holes oversize, filled with epoxy filler and redrilled, it's only the chain hole that concerns me.

I did not take out the balsa core but have had a ~275mm sq 8mm thick grp backing plate fitted inside the hull below decks. Because the windlass fixing studs also pass through the motor plate (around 200mm diameter) I think the load will be spread far enough that crushing of the balsa core will be avoided.

The idea of taking out the core around the chain hole using an allen key is a good one, unfortunately it's too late now and I think I will have to go with the silicone idea.

Can't fit a liner tube because hole isn't round (hole is comprised of a vertical hole drilled at 90 degrees + another the same size drilled at 45 degrees to permit the chain to "throw" forwards whilst winching in).

Thanks for the ideas and links,

Boo2


plate 14 inch

 

[nigelmercier]

I have drilled the fixing screw holes oversize, filled with epoxy filler and redrilled ...

How much oversize? A few mm or a few inches? You need the latter, achieved by cutting from underneath, or cutting out the core with an L-shaped tool in a drill. An Allen key works well.