Grub Screws

[Steveh24]

I have a rope cutter fitted to the shaft on my boat.

I take the boat out of the water every two years to antifoul it, but the last couple of times I've noticed the rope cutter has been spinning on the shaft because the grubs screws have become loose and I had used loctite, rendering it useless as a cutter.

Can anyone recommend a method of making sure the grub screws don't come undone once tightened.

 

[flappy]

I have a rope cutter fitted to the shaft on my boat.

I take the boat out of the water every two years to antifoul it, but the last couple of times I've noticed the rope cutter has been spinning on the shaft because the grubs screws have become loose and I had used loctite, rendering it useless as a cutter.

Can anyone recommend a method of making sure the grub screws don't come undone once tightened.

A good squeeze of chemical fixative in the holes before you put the grub screws in should help prevent any loosening..

 

[Trampster]

Not full of solutions Steve, but have you got enough clearance to use bolts instead of grub screws? I was thinking maybe bolts with drilled heads that you could lock in place with stainless wire through the holes in the bolt holes.
This sort of explains what I was thinking of:

 

[Steveh24]

A good squeeze of chemical fixative in the holes before you put the grub screws in should help prevent any loosening..

I've tried Loctite and that doesn't work, I was thinking of an epoxy, but I also need to be able to remove them as well to get the cutter off.

 

[Trampster]

A good squeeze of chemical fixative in the holes before you put the grub screws in should help prevent any loosening..

Steve said he had used Loctite which usually works, but it has obviously failed in this instance.

 

[flappy]

Pfte tape

 

[Steveh24]

One of the guys at the marina has suggested I use Sikaflex, which I hadn't thought of, would this work.

 

[flappy]

One of the guys at the marina has suggested I use Sikaflex, which I hadn't thought of, would this work.

Sikaflex® - The Leading Brand for Sealants and Adhesives

Sikaflex® is known as the world’s leading construction and industrial adhesive and sealant brand. Find out how Sikaflex® can help you make the difference.

www.sika.com

Don’t see why not.?..

 

[Topwater]

Or CT1

 

[Angrybear]

There are many grades of "loctite" if the one you used failed, then use a grade or two heavier.
Of course it might be that the threads have worn & you need to recut them a size larger or it might have been poor surface prep.
You could also try a centre punch to peen the thread or even a tiny tack weld

 

[Steveh24]

There are many grades of "loctite" if the one you used failed, then use a grade or two heavier.
Of course it might be that the threads have worn & you need to recut them a size larger or it might have been poor surface prep.
You could also try a centre punch to peen the thread or even a tiny tack weld

The problem is, whatever I use has to be removable so I can loosen the grub screws to take the cutter off.

I will have a go with Sikaflex 291i and hope that does the job.

 

[nearly70ty]

Serrated washer and loctite