AWB Spray hood fitting

[imeche]

I'm considering buying a spray hood for Knotty Lady and fitting it myself. I'm a chartered engineer and enjoy all types of DIY at home (yup even electrical wiring but don't tell anyone) but I'm terrified in drilling holes and fixing screws in Lady's gelcoat. The simple question is, do I drill the pilot hole in the coachroof, fill it with sealant and then screw the fasteners straight into the fibreglass or do I use rawlplug type anchors as I would at home? Sorry for my stupidity but any advise is welcome.

 

[MarAzul]

The few items I have fixed to the deck I've done just that drilled a pilot hole.I also used a counter sink bit ,slowly, to take the edge off the hole as previous attempts ended in the gelcoat breaking around the hole as the screw drove in. Obviously use stainless screws and seal the fitting to the surface with sealant. I use bog standard silicone, but other prefer more exotic varieties. It's worth a blob in each hole before you drive in the screws. Good luck

 

[davidpbo]

I believe on mine they are just screwed into the fibreglass with a dollop of mastic (presumably sikaflex or similar) underneath the fastening. Whether that is good practice or not I don't know. If you are thinking about plugs maybe epoxy might be the answer, drill the hole inject some epoxy and fit screw, may cause damage when removal was necessary.

 

[chwarae]

Hi
Just remember to reverse the drill to drill through the surface of the gelcoat as it prevents star cracks eminating from the drilled hole. Whatever you use to fix the sprayhood it needs to be sturdy as you will often grab on or fall against it. At least I do.
The sprayhood manufacturer will advise on what fittings to use. A good quality marine sealant such as dow corning will make the job waterproof.
Harry.

 

[srevir]

I have a 3 year old AWB which originally used screws to fit the sprayhood.

As Seajade says sprayhoods are convenient grab handles and there is a lot of leverage.

Mine now replaced with bolts and backing plates but this does mean that you have to drill all the way through and find some means of tidying up the headlining afterwards ( plastic infills as used on furniture in my case). If you do this you probably also need to re-inforce the space between the deck and the headining or, as I have, put the backing plate directly under the deck.

Its a fiddle but at least you end up with a solid job

Have fun

 

[jaybee63]

Drill taking great care not to pierce the inner lining. Most boats are double skinned, so once you pierce the outer grp, stop. Countersink all holes, this helps stop gelcoat cracking, and provides a void for any good quality marine silicon sealant (does not have to be sikaflex).
Be wary if the countersink is new, as if too sharp, may rip chip the surrounding gelcoat.
Most fittings used are self tapped. Tip, make sure you have the correct recomended drill size for the fastenings, and backscrew a 1/4 turn, every full turn, as when when tapping a thread (helps alleviate gel coat cracking)
Clean off any excess mastic..........finished.

Hope this helps, tips from the trade

John ...Tecsew ltd www.tecsew.com