Joe,

I have used cheap mahogany 1/8" plywood on two kayaks. No problems have come up yet. The boats were both experimental, so I wanted to keep the cost low. You can examine the plywood for voids by putting a 100 watt light behind it, the light will shine through the voids. I glass all of my kayaks inside and out, so the plywood has a nice protective covering, and the glass is where the main strength is anyway. The thin face veneers call for care in the building process, but after the glass is on, they behave very closely to thicker veneers. I am certain there is a slight loss in strength, but is is minimal. I believe it is an area that one can cut costs, if a little extra care is taken in the building process.

It is nice to prototype a kayak for under $150. The plus side is that the seem to hold up just as well as the ones made with marine plywood.

If I was producing kits for other people, I would use marine plywood, mainly because it is slightly easier to work with.

I do get more comments on the wood (very figured grain) on the $140 kayak, then I get on the wood, in my much more expensive Pygmy kit kayak.

Mike

: Grant,

: Like with many things there is no one 'right' answer - only
: compromises/choices. Each of us see these cost/benefit risk/reward ratios
: differently. With that understood, I have a moment to repeat some things i
: think every body 'knows' on this topic (it's been well discussed here and
: elsewhere).

: The 'cheap' ply has the advantage of being cheap and redily available and
: most often also uses exterior glue. The 'downside' to the product is 2
: fold: 1. the 'face' layers are THIN (too thin, i think) and the 'core is
: thick. Makes for an product that is 'unbalanced' structurally and when
: stress is applied it will be liable to react in sometimes
: undesirable/unpredictable ways (who knows maybe you will get 'lucky' here
: and not have anyhing like this come up). The layers are not strucurally
: designed or built for the uses a boat requires (I think). 2. The 'core' is
: often made from scraps of wood and may be laid with who knows how many
: small-medium voids. These voids are a real variable that is hard to
: control or predict in advance. Alhough one possible way (if it wouldn't
: ruin the sheet) would be to pre-soak the sheet and examine for voids. All
: that show up could be repaired from the back before you started building.

: Anyway I'm in construction and I tend to be the concervative type (been bit
: too often), but I do know more than a few guys who approach everything as
: no big deal and they jump right in breaking the 'rules' and doing it by
: the seat of their pants and IT WORKS OUT FOR THEM.

: I mean I've seen these guys do stuff just like your saying using a door skin
: when the job should have quality veneer, but it works for them (not me,
: some how when I take short cuts it comes back to make me wish I hadn't).

: SO you could be just fine going to buy the luan doorskin and may end up with
: a great boat the low cost, low stress way. If you're one of the lucky
: ones, great it is nice to have that going for you. For me I would look at
: the cost of 2 (or so) pcs of quality ply as a pretty small part of the
: over-all cost of building a boat (especially if I counted my TIME). and I
: wouldn't (for me) want to put all my work on such an admittedly
: substandard product (for this purpose). I think a dorrskin is great for
: something like that application, but a BOAT is really not what the product
: was engineered for.

: I have a friend who knows a little about building, but he is always
: remodeling his rental properties. Anyway he wants nice 'french doors' but
: won't pay for them so he builds them himself. He just goes to the lumber
: yard and buys regular studs (2" X 4"'s) and makes them, just as
: simple as that. But his doors always twist and fall apart after a few
: rains and he struggles to fix them from then onwards or has his tennents
: just 'live' with those drafty, sticky doors. It just stands to reason that
: the wood just isn't the right type to make a good door with, but he goes
: on and builds them anyway (he syas it them or nothing, so I guess he has a
: point) the doors have been there for years (probably 40 doors or more in
: all). I think he has balls, because if I went to a 'real' door
: manufacturer like T.M.Cobb and said "Hey, make me some doors out of
: these 2" X 4"'s will ya? They wouldn't even take a breath before
: they said "No can do with that 'junk', pal!" But that doesn't
: stop my friend and he has over 40 doors to 'prove' it. Somehow I have this
: idea of 'seaworthyness' that is hard for me to 'forget' when it comes to
: my boat.

: No right or wrong about it, just whichever choice is better for you, good
: luck either way. Maybe a 'cheap no stress boat' is a great idea .... Who
: knows it may out last us all.

: Joe