Mounting winches

[bilbobaggins]

I need to mount a pair of extra winches - and clutches - on a friend's curved coachroof, for halyards and reefing lines, and am seeking some input from experience from them 'that knows what not to do' ./forums/images/graemlins/grin.gif

I have the Gougeon Brothers' book showing their way ( using a substrate/bed of epoxy putty ) and expect to use that, but with a rather thinner bed of putty. The headlining below is stripped, and I plan to fit a plate of aloominoom underneath, with another gap-filling' smear of epoxy putty, to stiffen and to spread the loads. The bolts/nuts are to hand, and we have a winchbase template.

Apart from negotiating a goodly consideration of beer tokens, is there anything else I should prudently consider?

/forums/images/graemlins/smirk.gif

 

[oldsaltoz]

Need more information:
Winch size and expected loadings. Deck type, solid glass, composite, and an estimate of thickness. You will also need backing for th clutches.

 

[bilbobaggins]

The winches are elderly but little-used 40's, non-ST, with a base size of about 150mm. The layup is solid GRP, about 6mm, and I expect to run an aluminium backing plate of about 50cm. x 20cm underneath both the winch and the jammer-pair, on each side of the companionway hatch.

I expect to lead back from the mast-foot the tails of a main halyard, a spare halyard, a topping lift, 3 reefing lines, and two 'lazy jacks', into 1 Spinlock clutch and a triple Spinlock jammer, each side. ( owner's choice )

Loadings are unknown, but the boat is a Rival 34 monohull with quoted 560 sq.ft of sail.

 

[Cliveshep]

My comment FWIW is I would use a steel backing plate as your proposed ali one will flex too much and "dint" around the fixings. Hammerite painted mild steel would no doubt serve as the headlining will cover it up I assume. However, I would make it as big as you can to spread the loads over as greater area of your friends coachroof as possible and as thick as you can handle, certainly not less that 5mm. The other issue is of course how firmly supported/fixed is the putative coach roof? Most are designed to resist wind loads upwards, is this one strong enough to take a pull other than downwards? That's for you to take a risk on. Best of luck.

 

[William_H]

Being halyard winches the load is going to be pulling the winch forward. So a backing plate that extends aft to the edge of the cabin roof will give the most support. Even to turning downward a little at the corner of roof and bulkhead.

It is desirable to have the ropes approach the winch from level or a little below the bottom of the winch to get the turns on without overide.

good luck olewill

 

[oldsaltoz]

Ok, I would not advise Aluminium backing plate, it may not be strong enough unless very thick and this cause problems with the lining; the combination of stainless bolts and nuts may also cause corrosion problems down the track.

I would also avoid what you describe as epoxy putty.

Winch and clutch installs should be very strong and maintenance free, using the righ material and combinations is very important.

Start bu fitting any turning blocks at the mast base and run lines through the clutched and take a turn around the winches, position the winches and pull the lines tight to align the clutches. Mark the holes to be drilled on the deck. Check below deck to ensure the area is suitable.

Drill the holes at least 6 to 10 mm oversize, depending on how many mounting holes you have, consider at least 4 by 6 mm bolts for the clutches and 4 by 10 mm bolts for the winches.

Backing plates should be 6 mm stainless steel, size should be the distance between bolts plus 50%. So with say 4 bolts 100 mm apart the plate should be 150 mm. Make sure the corners are well rounded and the both top and bottom edges as well. Use a grind stone rather than a file and it will not rust stain.

Remove the winch drum and poison it over the drilled holes, coat the bolts with a 'wax' polish or or several coats of mum's hair spray, this will prevent the epoxy gripping the bolts.

Now take the backing plate and lay it on deck alighning the drilled holes, mark the edge with a pencil on deck and mask off the area outside the winch base plate.

Next mix some epoxy resin and Micro Fibres to about peanut butter thickness, apply this to the deck and lower the winch base plate onto it, inset the bolts.

From below deck, apply a cone of epoxy and micro fibres to the upper side of the backing plate and push up slowly till you have the corners about 3 to 5 mm from the underside.

Clean up any excess material with a gloved finger and then use some Acetone to remove the last traces. Do the same above deck but put a slight angle between the plate and the deck.

Note:
Do not tighten the bolts, do that only after the resin has cured (24 to 36 hours).

Everything must be very clean and very dry before you start, temperature should be above 16*C and humidity above 75%. Use wide shallow containers for mixing, this will extend pot life and reduce the chance resin self heating.

I hope this helps.

Avagoodweekend......