Mark,
Fiberglass will not hold any type fastener period. No exceptions. As
fiberglass is a low density material, you must spread the load over the
largest area possible. If there is low density space between the outer deck
and the load bearer, you must use compression posts or tubes in between.
Last but not least, any hole you make through the fiberglass must be
resealed to prevent water absorption through osmosis along the length of the
glass fibers. This absorption, if it occurs, will hydraulically jack the
laminations apart leaving water filled blisters behind.
Steve

rk Hindley" wrote in message
...
I am trying to find a way for installing a liferaft on our Halcyon 27.

I only have the space to store it on deck and was planning to fix chocks
to the foredeck for the canister. However there is a fixed grp
headliner beneath so I have no access to install a backing pad and bolt
through.

Is is feasible to use fixings similar to those used for
plasterboard/hollow walls and just screw in from the top? What area do I
need to spread the load over for a 32kg raft?

Any other suggestions of how to manage this?

Many thanks

Mark