So today I walked into my garage and noted the Hollow Wooden Door (HWD) that I use as a table and wondered about shaping it a bit and coating it with some epoxy. The dimensions are 200x75x4.5 cm and it weighs only around 5 kg. Unfortunately, I’ve got no idea what type of wood it is but will try to find out. I know it sounds ridiculous (which it is) but it seems like a very easy and iconic board to make… and even if it fails you could still use it as a table or something. After seeing some of the wacky boards produced on here I am sure someone has thought of this / done this. Are there any obvious limitations that would not make this possible to shape and glass?
Any thoughts, suggestions, or lacerations are welcome.
I believe the hollow door is a torsion box composed of multiple “chambers.” It is unlikely you could flex the board before glassing to add bottom rocker. It will be like surfing a board without rocker.
You will have to come up with a way to seal the open rails.
Should float being hollow.
The glass and resin will increase weight. Shouldn’t need a heavy glassing schedule with its outer veneer skins.
If you got the time, money and inclination, the end result would be interesting.
Umm, first off, it’s prolly made with a thin Lauan veneer skin over interior reinforcements and edges of Fine Pacific Rim Cheapwood.
As has been mentioned, the interior is a whole lot of air with a little wood here and there to make boxes as a stiffener. If you punch one ( don’t ask) your fist will go right through unless you get unlucky and hit the reinforcement, in which case it hurts quite a bit. But this makes putting a fin box on the .thing kinda challenging. But here’s where the builders supply is your friend, Get the densest ( and lowest expansion ) spray foam insulation you can find, drill a couple holes and lay it on like you were filling an eclair, careful lest you use too much and blow the skin off it. Then glass with ‘what’s on sale’, rout for your fin box, have at it.If you don’t mind something that’s not ‘water clear’ resin, I’d suggest what they call ‘boatyard resin’, sold by the gallon, turns a bit reddish brown as it goes off which might compliment the Lauan nicely, really bring out the lovely reddish brown grain of the inexpensive veneer.
Shaping it? I don’t think so. Besides, if Slater can surf that multiple concave six panel Molded Craptastic door, imagine the speed you can get out of this thing with so much less drag. Take it out on crowded days and all of a sudden they’re not.
Haha thanks guys this is exactly the kind of advice I was looking for! Gives me a chuckle imagining what it could look like, nevermind surfing it.
Doc, for the spray foam it is only meant to provide structure for the fin box to set in, and not as added structure/strength for the whole board, right? Will definitely go the boatyard resin route (which is essentially polyester resin?).
What do you guys recommend as the glassing schedule?
Since you give the dimensions in metric units I assume you are not in the US?
Hollow interior doors in the US are luan plywood skins on spruce frames, typically. They have corrugated board placed on edge in a zigzag pattern between the skins to act as stanchions and prevent the plywood from flexing a lot. You could get a little rocker if you bend the door before glassing and do it in a warm space or in warm weather in direct sunlight.
I once put a coat of primer on one on a hot day, outdoors. The door was supported on sawhorses at both ends and it bent all by itself due to saturating it with paint and leaving it in the hot sun. So they do bend fairly easy.
Yeah, exactly, the veneer is good enough for a door, not so much for holding a fin.
Likewise, yeah, the ‘boatyard’ resin is polyester, inexpensive, which is, I think, just what you want here. It comes waxed and unwaxed, I’d buy a gallon of waxed and do all your glassing when the previous layer is still tacky or else sand lightly between.
As SammyA mentions, you may be able to tweak it a bit, we used to leave ready-to-glass plywood skimboards outside overnight with the bottoms up, the dew would dampen the upward facing veneer a little, expand it a little and dish it a little convex, which could help some, though it wouldn’t be as good a work table
As an aside, I once left an old pre-primed hollow interior door (the kind sold at the big box stores) outside in the weather. In short order it was reduced to a pathetic pile of cardboard mush.
