JEM Watercraft

I have decided to spend my winter in the basement building (stitch & glue) a Freedom 15. My hope is two fold, First that I can get it out of the basement when complete and second that it stays afloat after I plant my cacass in it. My question is about the wood to use. I believe that Okume (?) is the type but what about the thickness? I see 3mm 4mm and 6mm available. As far as the stitching goes I've seen people use wire (zip) ties and copper wire any pros or cons to either way?

stitching

wire
pros
- smaller holes are almost invisible if you want a clear finish
- cheaper
- easy to adjust
cons
- can be fiddly
- sharp ends
- drill bits are easier to break (1mm)

ties
pros
- easy to tighten
- 4mm drill bit
cons
- holes need filling
- more expensive

I would imagine that 4mm ply and 6oz glass will be the way to go and the ballast that some of the paddlers here talk about I'm sure if you can get you and the boat out of the basement you won't sink it when you "plant your carcass in it"

Tor

GO the copper wire

Have you ever tried to back off a zip tye if things didn't look quiet right

Last time I used wire I ended up with so many puncture wounds I looked like a King's Cross junky .
Zip ties forever! If they are tightened in stages there is rarely a need to slacken them off and in those cases it's just a cut and replace.
It all comes down to personal preference in the end.

The ratio of wood to glass is a bit of a personal thing too. I believe that slightly thicker ply and thinner glass is best for stiffness to weight ratio but that's not always the priority. More glass is going to be a bit better if the hull will be treated roughly (dragged over rocks etc regularly). My Laker had to be 3.6mm ply and 2oz glass so I could lift it - but I know I need to be careful with it. Build according to the intended use and care level (bearing in mind that the care level can drop a bit over time ).

Hope it all goes well.

I like wire, but it doesn't have to be copper. Copper is more expensive than other types. I found some non-copper wire at True Value Hardware. 100' for a couple bucks. The stuff I had was pretty thin so I used a 1/64th inch bit. On areas where there was a lot of stress I would double it up to prevent breakage.

I like the 4 oz cloth from Duckworks Boat Builder Supply. its real easy to work with and finishes very clear. I used to use 6 oz, but have since decided that it is too much of a PITA. The only place I use it now is inside the boat where it wont be seen, or as an abrasion strip on the bottom covered in graphite/epoxy mix. Once its all gone, I won't buy it again. With the 4 oz, I cut a football shaped piece to cover just the bottom panels then cover the entire boat in another layer of 4 oz. This way I have 8 oz on the bottom. It adds a little weight but increases protection from abrasion. Besides, the boat will still be lighter and stiffer than any plastic boat you can buy of comparative size.

I hope you enjoy your build.

These are just my personal preferences.
4 mm ply (I used 3 mm Once never again)
6 ounce glass inside and out,and to beat a old horse the inside may be more important than the outside.
I like the zip ties,and I use a brad nailer on the decks
Ron

I thought this might be useful to repost rather than link to my build log

I have a little tip which made life a hell of a lot easier on my poor white collar fingers also a bit safer if you have 3 and a half foot helper in the shop.

Insert stitch from the out side



3 half twists on the inside



pinch



to look like this



find a convenient slotted piece of dowel



twist



look at that beautiful stitch and safe on the outside

Tor

I guess I am the one who marches to a different drummer. All I use is 1/8th wood or 3 mm for my boats. Copper wire for the ties and 3.25 tight woven glass on the outside and normal 3 or 4 oz glass on the inside. The graphite and epoxy on the bottom or the interlux bright sides with Teflon in it.

It has let me make some light weight boats since the weight of the boat is something I have to watch. I do baby my boats and try not to abuse them , when possible. A river that has rapids in it can't be helped when you are taking a 4 night 5 day trip down the river. Which has happen to me and the boat came out in one piece. I was told there were no rapids in the river , it was rapids after the 1st 5 minutes on it and all the way down.
99.9 % of my paddling is quiet rivers with sand or mud bottoms.

Chuck.

Thanks for all the help and tips! I'm looking forward to getting my lumber and starting on this project soon.