Screwing hardware to wooden deck. Help?

D

David Stern

Active member
Hello:
I am upgrading my Devlin Snowgoose in the next few weeks. I want to install navigation lights, a compass and some tie down eye-straps to attach camo to.
When I screw in the screws into the deck or in the case of the lights have to drill through the deck or hull, what should I use to seal out water? The boat is fiberglass over plywood.
I know this is basic stuff but I really want to keep the water out of the ply.
Thanks
Stern
 
David,

3M Fast Cure 4200 is a good bet. 4200 allows it to be removed down the road VS 5200 which creates a permanent bond, (i.e. replacing nav lights or relocating tie down points). This product creates a watertight seal.

Griffin
 
So would you drill pilot holes and then dip screws into 4200? What is the prevailing wisdom on this. There are many boat builders here on this site. How does everyone approach this issue?
Thank you
Stern
 
I use 5200, don't care about removal. I coat the back of light or other attachments and then dip the screw. Can be a bit messy, but 5200 really holds and creates a waterproof seal. If you have to remove down the road it can be popped off with a dull chisel
 
I keep a small tube in the garage frig all the time. The white can be found in 5200 and sometimes 4200 at Hope Depot. They also sell it in the caulk tube, but I usually waste more than I use in the large tube to not worry about the potential cost savings. If you want to get black or brown, you have to mail order or get luck at a marine store. I know the place up the road from Tuckerton (Parkertown maybe) has it in black at least, as I bought it there.

I always predrill for mounting hardware. Use backing if the anything will see stresses, don't rely on just the deck material, but I always overbuild. Remove the paint where the new items are going.... sand or solvent. Clean and dry with solvent.

Butter up the item to be mounted and squeeze into the holes too. Wear gloves, 4200/5200 is messy! It will take a bunch of papertowels and solvent to make everything look pretty. Allow to set for an hour and check fillet again. I sometimes will get some additional squeeze out, but it can be trimmed after cure with a very sharp razor. Paint will sort of stick if applied while the 4200/5200 is uncured. i usually just clean to a very fine fillet and don't worry about paint adhesion, but did buy black for that purpose after my first build.

Dave
 
I mounted a wood block a little larger than the light, sealed the holes and matched the hull curves. Also raises the light above the grass. Can be worked on easily.
 
You must log in or register to reply here.
Back
Top