Setting bolts into GRP surfaces

[johnjfrake]

I would like to bolt the plywood floor of my Folksong 25 down securely and thought that a good way to do this would be to set some bigHead GRP bolts into the keel floor and use a sort of T section nut (again with a wide area head) to grip the floor in place! Does anyone have any experience of this technique or any comments on the idea. Note the bigHeads will be set into the grp above the keel centre, not where a fault would cause leaks. Don't want any bit protuberences above the floor for obvious reasons.

Regards

John

 

[KenMcCulloch]

The cabin sole on most GRP boats rests on wooden bearers bonded to the GRP structure, and if it's thought necessary to screw down the sole boards the screws can go into the bearers. You should however think carefully about the disadvantages of doing this (you have already presumably identified some advantages). You may need access to some part of the underwater hull in a hurry, perhaps if you are trying to trace the source of water ingress, or to gain access to wiring, pipework or pumps, in which case permanently secured sole boards may not be a great idea. Whatever you do simple and strong is always best.

 

[Rigger Mortice]

Personally, I would prefer to do it the other way...fix a bighead nut below and screw through the plywood floor into that. I can't see why your way won't work though.

On my boat it is done exactly as Ken has said above.

 

[Madhatter]

TBH it sounds like a lot of work for a simple solution , why not use twist latches -secure ,quick access reasonably easy to fit .

 

[johnjfrake]

Thanks for all the inputs.

I do not want to fix the floor permanently in place. My reason for fixing it at all is that in two years or so I intend to do the AZAB preferrably under the auspices of ther Jester Challenge and would like not too have to worry about the floor if she gets laid on her side.

I may divide the floor into 2 sections to make it easier to manouvre when lifted.

I dont want to screw into the wooden bearers in case water gets in and rots them.

I will definitely bond the big head nuts into the grp floor and try to make the bolt heads sink flush with the floor surface, at least they will be as low profile as possible.

I don't want to use latches for two reasons, firstly I don't altogether trust their strength and secondly on my boat there is no way to make them flush, they would protrude and be infinitely kickable.