Lewmar winch screw

[Parmesan]

The previous owner of our yacht has left a winch (Lewmar Wavegrip 30) with a seized screw (one of the four in the top cap).

It seems that they have tried to remove the screw at some point by cutting a slot, but still not been able to remove it. The shape of the top cap makes it hard to cut a slot that is deep or wide enough to fit a decent sized screwdriver. The other three screws are fine and turn freely.

Has anyone had a similar problem and have any suggestions for how to remove the screw? I have serviced the other winches and they are quite dirty inside, so I need to inspect/clean this one as well.

Thanks in advance.

 

[fredrussell]

I’d get a (manual) impact driver on that and give it a few taps. If that didn’t work, and winch is working, I’d leave well alone and use as is.

 

[KevinV]

Yep, manual impact driver - perhaps first increase the slot a bit with a dremel

 

[ducked]

And a penetrating oil. Leave it at least overnight.This may not do any good but will raise your morale, like fire support against a dug in enemy is said to do. It might be worth making a dam around the screw head to retain extra penetrant and provide a slight head.

And perhaps local application of heat. Since the screw is in a big heat sink, using direct electrical heating from a 12V car battery might be best, perhaps with a carbon arc electrode, if you can get hold of one (gutting dead dry cells might provide a free alternative but the last time I tried that the electrode was mush, and they might all be like that now). Take precautions against the car battery exploding.

A traditional blowtorch-heated thermal inertia copper soldering tip might be another alternative, especially if you are prepared to butcher it to maximise contact with the screw head.. They tend to be a bit too pointy configured for soldering. I suppose you could put current through this too, though I've never tried that

Couple of years ago I came across the tip of a lightening conductor in the campus car park, which might have worked nicely for this sort of thing, but annoyingly I didn't think of it until later, and when I went back it had gone

 

[justanothersailboat]

wow Ducked, you don't mess around :-D ... true that heat is good, but slightly less heat and slightly more diffuse may be enough

Previous slot-cutting exercise looks halfhearted. There might be room to clean up the slot and improve its shape with a Dremel cutting disc if you are feeling dexterous - I would probably try that before attempting an impact driver.

 

[PetiteFleur]

Cut a better slot with a Dremel tool and you should be able get a decent screwdriver to turn it. I have a heavy duty screwdriver with a hexagon just under the handle, leaning heavily on the screwdriver then turn with a spanner on the hexagon. Worked for me recently when I repaired shed doors which I had built any years ago. We had been recently burgled so I fitted 'uni-screws' to fit the hinges. No longer available, with a triple hexagon driver which was worn. Cut a slot with my cordless grinder with a 1mm thick cutting disc and easily unscrewed with the screwdriver.

 

[Stemar]

What is the top of the winch made of? It looks like some sort of composite material, rather than metal, in which case I'd be VERY cautious about any more than boiling water.

I'd be more inclined to drill it and see if an extractor would shift it. As a last resort, drill the head off so you can get the winch apart, and there should be enough of the screw protruding to get Mole grips on it.

Whatever method I used, I'd leave it to the winter. Now's the time to be sailing.

 

[johnalison]

I don’t know this winch but I would be wary of continuing to use an unserviced winch. I would go for the penetrating oil and impact solutions first.

 

[dansaskip]

Very often with damaged cross head screw slots you can very carefully peen in the slots by use of a ballpeen hammer and a suitable drift. Then you can "remake" the crosshead slot by gently tapping in with a hammer the correct size crosshead driver. The gentle impact also tend to break down the corrosion that is hindering its undoing.
It is always the first thing I would try and works far better than tying to cut a slot or drilling out the screw. Especially so if it is SS which is a bugger to drill.
It is a trick I learned years ago working on Japanese motorcycles which often suffered from butchered heads as a result of people not knowing what they are doing. Yes give it a dose of boiling water and or penetrating oll as well