Filling grab-rail holes and bronze screws info needed

[Harry P]

I've removed my external wooden coachroof grab rails for varnishing. Unfortunately some of the screws had been replaced with stainless steel ones that had rusted enough to stick in the wood and shear as I tried to unscrew them. I had to drill out the remains of the screws from the wood so have been left with irregular holes. They don't go right through the rails.

Three of what must have been original screws (bronze I suspect) came out easily.


My questions are:

What could I fill the holes with that would be strong enough for holding with screws when replaced (and unscrewed in the future if needed). They are hidden so colour etc doesn't matter. I suspect some kind of epoxy might do. Is it sandable and strong enough for someone swinging on it?

Where can I get 4 1/2" bronze woodscrews?

Cheers
Harry

 

[sandeel]

bronze screws

I found this company excellent when I had to source some beefy bronze screws.
Similar to the old GKN type woodscrews.
Anglia Stainless

 

[LittleShip]

You can get plug cutters to make wood plugs, this will allow you to drill a neat hole and epoxy a new piece of wood into the hole and then re-drill for the new screws.
Anglia stainless can supply you with any size of silica bronze screws that you need. if you only want half a dozen a good chandlers will be able to help out.

When refitting the grab rail make sure that you seal around the screws to prevent water ingress in the future.

Tom

PS If you want 4 1/2" (thats four and a half inch in length) bronze screws, make sure you are sat down when they quote you......... I had to buy 175 of them

 

[PCUK]

How about moving the rails half an inch forward or backward to give you new superstructure to drill into. Must have been poor stainless to rust. Neither A2 or A4 should rust sufficiently to fall apart.
Grab rails should not be screwed under any circumstances. Only nuts and bolts are acceptable for such safety related items.

 

[Boathook]

My surveyor condemmed my screw in grap rails for being fixed by screws and other holes. Ended up fitting new ones through bolted with s/s coach bolts?, the ones with a dome head and the first part of the shank square. I feel much happier now ....

 

[xtiffer]

Mistake....Sorry

 

[andygc]

Neither A2 or A4 should rust sufficiently to fall apart.

But when buried in wood or glass-fibre with poor sealing at the interface between the two pieces they are holding together, they do rust sufficiently to form a waist and to fracture when somebody is trying to unscrew them - stainless steel is only stainless if it is exposed to oxygen. That's why the screws used to fasten hood ends in wooden boats are bronze, not stainless steel.

 

[MrCramp]

Grab rails need to be strong enough to save a life!

I would consider replacing the rails unless you are certain that they still strong enough.

As others have said under no consideration should screws be used. They should be bolted with decent sized washers or backing pads, depending upon the thickness of the fibreglass.

 

[PCUK]

Debatable Andy. If they are dry then there should not be a problem.

 

[andygc]

Debatable Andy. If they are dry then there should not be a problem.

Agreed - that's why I wrote "with poor sealing at the interface between the two pieces they are holding together". There's little chance of keeping the joint between a handrail and a coach-roof completely dry.

 

[PetiteFleur]

How old is your boat? There was a time in the 60's & 70's when steel screws were used which of course rusted. My Halcyon 23 had steel screws fastening the handrails to the coachroof - only discovered when trying to find an elusive leak. Replaced with through bolted bronze bolts from Anglia Stainless. The rubbing strip also was fastened with steel screws an again replaced with bronze.

 

[Harry P]

Thanks for all the input and advice.

My boat is a 42 year old Albin Vega. The screws were are Andy described, the damp had formed a waist of rust. I believe the water has seeped in very slowly over the years. There's absolutly no sign of damp in the coachroof. One of the reasons I took the rails of was to reseal this area as water gathers along the edge of the rails and had soaked into the wood.

I'd thought of drilling and plugging but the holes are very irregular now and therefore very hard to drill for plugs. They are however tapering, in the good way. Any filler should be wedged in and not come out easily. Any suggestions for fillers as in my original question?

Cheers

 

[sandeel]

Filling grab-rail holes.

Hi
I would use epoxy as you suggest, I have used WEST myself, but any of the others are similar.
Firstly use unthickened epoxy resin to saturate the holes, using a small brush, so as to get a good bond to the wood, then fill the holes with epoxy thickened with a mixture of microfibres (which give a cross bonding strength), and colloidal silica (which stops the resin sagging), however in my experience don't overdo the silica as it causes the resin to become brittle. Try to get the surface flush as it is difficult to sand later. Pilot drill the epoxy when hard. As it will be near impossible to screw into without.
good luck

 

[Harry P]

Thanks for the info Sandeel et al.

Harry