From Bob's Basement

NOTE: This is a living document and is subject to change as I go though the construction process. Check back often!

Contents 1 Aim 2 Photographic Evidence 3 Conclusions 3.1 Order of Construction 3.2 Construction process 3.3 Choice of Materials and Equipment 4 Progress

Aim

To build a scale model of the boat to find any difficulties or issues which may arise during the main construction, and find a working solution to them.

Photographic Evidence

On Flickr! Video footage coming soon (as soon as I've managed to make Vegas work)

Conclusions

Order of Construction

• Mark out sides, ribs and bottom.
• Cut ribs and transoms roughly
• Shape ribs to size.
• Laminate ribs using epoxy.
• Cut out a keel with 24mm notches at equal distances along it, the length of the flat bottomed part of the boat.
• Slot ribs into the keel and glue, using a square to align them.
• Glue ribs to one side
• Plane the bottom edge of each side to be flush with the bottom of the ribs
• Glue bottom onto ribs and side
• Glue other side to bottom and ribs.
• Plane sides of the bottom to be flush against the sides
• Use some maths to work out the dimensions of the bow and stern panels, using measurements from the construction so far.
• Cut end part, glue onto the sides and bottom, for both bow and stern
• Plane the bottom edge to be flush with the bottom.
• Plane top edges so they're flat (optional)
• Check all joints for watertightness and seal if required.
• GENTLY sand all external faces, then apply some beeswax (or other fuirnature wax) using wire wool.
• Rub with dry wire wool, then apply a coat of varnish.
• Once the first layer of varnish is try, sand it down again then apply a second coat
• Bask in the glory of a job well done.

Construction process

• MAKE A KEEL. Although, structurally, it's not nececary, it would really help in construction to keep everything square.
• Shape the ribs as one. To ensure consistentcy. This will ensure that they stick to the sides well.

Choice of Materials and Equipment

• Glue: For laminating boards together, use an instant 2 part epoxy (can be bought for a fiver at a hardware store). For large surface area it works excellently. For joints, use PVA. Not only is it waterproof (and works as a sealant), it's also much more flexible and works better with smaller surface areas. Epoxy is brittle and doesn't stand up too well to shearing forces - for big flat things it works great.
• Sealant is probably unnececary if you use PVA. However, having a bit of silicon sealant handy for the odd gap is a good idea.
• Have plenty of big clamps to hand! We were a little short of clamps and found it to be an issue. What'd be great is some large alligator clamps
• Don't nail plywood. Even though I knew it was a bad idea to start with, I've proved it.
• A false floor is a really good idea. And the drawings for an appropriate design for one will be around here shortly. It's pretty easy to make, providing all the ribs are consistently spaced (see above point about making a keel). We might want to use a thinner kind of ply for the floor to save weight.
• Someone needs to work out a good way to get the props in the water without sinking the boat. We can't make the stern too shallow a gradient or we'll have no room for batteries or motors. The props will need to be well below the bottom of the boat to provide any real thrust. I'm thinking some kind of marine bearing might work.
• Get a decent saw. Although a jigsaw will work, it'd be really handy to have a saw that's capable of cutting perfectly straight lines - preferably a table saw but we shall have to make do.

Progress

Up until now, we made the bottom and sides, but we tried to glue on the ends, but it seems duct tape isn't a sufficient clamping force for glueing, and as such they fell off. We need to work out a suitably clever way to clamp the ends on.