JEM Watercraft

Hi KJ & chuck,
Thanks for the links mates.

My duck is not a thing of beauty and I am pretty ashamed of it. It was the my first ever attempt at building a boat and the mistakes I made were many and varied. Having said that, they are a fine hull with good allround performance and I think, dont need a keel.

If anybody is interested I will post a list (long) of the mistakes and stupid decisions I made when making her.

hairymick wrote:If anybody is interested I will post a list (long) of the mistakes and stupid decisions I made when making her.

Well, Mick, confession is supposed to be good for the soul. I'm sure - yea, extremely sure - that each of us who have built boats could run stiff competition on that error list. Me probably more, because once I got how to make mistakes down pat, I'm loathe to give up something I'm good at.

I've developed some self-defense truisms:
1. Part pf the fun, is learning how to do it better next time.
2. A well scratched boat is a well loved boat.
3. I built a tool of the trade, not a piece of furniture.
4. "What error??!! Get your DAMNED hands off my boat!"

Oh man...you should see the TANK that was the first boat I built.

The instructions weren't very clear and I didn't take my time at all. Made the fillets about 2-3 times bigger than they needed to be, about 8 coats of epoxy trying to fill the weave of the fiberglass.

It's since sat upside-down in my back yard as a reminder of what level of quality and detail boat plans need to be.

Hey Jack,

I like your response No 4 best of all.

Matt,

I don't think there was anything wrong with the plans. They were clear enough but in my wisdom, I thought I knew better.

My mistakes went from choice of wood to strip width to type of glue used.

For my practice sg I am using a cheaper ply and timber, but apart from that will stick very closely to your drawings and suggestions. I will use this boat for fishin and other generally pretty rough and tumble stuff.

THEN the real fun begins. My plan is to do as nice a job as I possibly can on the second boat.

regards,

Mick

Mick,

If you're determined to use a cheaper grade of wood for this practice boat, go ahead. But I would urge you to use only the best wood in the future. Cheap wood has fills - & worst of all - voids.

There are hollow spots in the middle of the sheet of wood. When you bend and mold the wood, it has a different resistance and twists at a different rate than other wood nest to it. You can get a bulge or break at that area.

I'm not a very good craftsman, so I have to use the very best of materials to help rescue me from myself. Mahogany AA (1088, now, I believe) is the only thing I use. Anything else and I look REALLY bad instead of just clumsy.

Good points Jack - thank you - i hadn't thought of that

I will re-consider my options. Okuome ply seems to be unheard of here. Is it similar to Gaboon?

hairymick wrote:... Okuome ply seems to be unheard of here. Is it similar to Gaboon?

Uuuhhh - I have no idea. Something got lost in the translation there. If your lumber folks there can't answer, let me know and I'll make inquiries here in the CONUS.

(I thought a gaboon was a long armed, striped arsed ape)

Unlike Kayak Jack I only use the totally outrageous expensive Luann door sheet Plywood at $9.95 for a 4 X 8 sheet of the 1/8 th inch on my pirogues.

They end up being less the 40 pounds for a full size pirogue and in fact they are at 32 pounds when done and that is totally fiberglass encapsulated.

It is not the wood you use .......... it is how well you can make the boat and how you do it or for better words the builders expertise.
Mine are totally epoxy saturated and all of the voids are filled in with epoxy and wood flour before being glassed and epoxy saturated.

I do not want any wood that is not capable of being saturated with the epoxy and if it means I have to fill in some voids with wood flour and epoxy .... Big deal. What I save on the cost of the wood makes a large difference in the total cost of the construction of the boat.

I am thinking a person could make one out of news papers if it was epoxy saturated and fiberglassed.

Think about this .............. The wood is nothing more then the filler or core of the boat and it creates the looks or character of the boat .. the fiberglass is the real skin of the boat and what offers the structural integrity of the boat unlike the filler (what ever it is ) which creates the shape of the boat.........Now you can leave it natural or paint it .. what ever the builder wants to do since it is his boat and being built the way he wants it.

Epoxy saturated paper, wood or anything is a lot stronger then that item before it is epoxy saturated and then for more additional strength fiberglassed on the outside and inside. Take a newspaper and fold it ..... Now epoxy it and then try to fold it........ You will find it is a lot harder to do.

Jack and I always disagree on the type of wood to use but I am willing to bet someone could make a boat out of paper and when epoxy saturated and glassed have one darn good boat.
Right now I am making one out of Redwood strips.

Building boats for a persons pleasure is nothing more then common sense and imagination and it is the imagination process that makes this so much fun for all of us since there are no established rules about how to do it.
Sometimes thinking outside of the box is more fun.......

Just personal choices and what a person can think of. Then all of us learn something and if all of us thought alike then all of us would be paddling the same type of boat ........... BUMMER.

Chuck.
PS... I am making one out of Redwood and one person made one out of Balsa and others have made them out of some wierd stuff including concreat and to the extream ..paper ( which is wood)

OOHHhhh, Chuckie Chuckie Chuckie. What am I gonna do with you?

I agree with you to a point. But, to think that the filler core does not contribute to overall hull integrity is an oversimplification of the situation. The total strength of a hull is the sum total of the strength of the core (wood) AND the two epoxified fiberglass skins.

Comparing two hulls sandwiched in identical skins of fiberglass & epoxy, one of plywood and the other of cedar strips, I would certainly expect a plywood core to be the stronger. Simply because the plywood is stronger than the strip to start with.

Adding more strength with two skins just adds more strength to what existed already. Adding epoxy and glass does not weaken plywood down to the strength of a cedar strip, a balsa strip, or a piece of newspaper.

Otherwise - we could have a two-skinned hull with a hollow core and it would be just as strong. But, that is probably not realistic. While there may be only a small difference between the overall strength of good wood and cheap wood, a clear finish tells a story too. If the wood is painted or covered in opaque epoxy, then the differences could be even less.

As I said, I'm a not very good craftsman, so I prefer to use the best materials. Nice things about building our own boats is - we can satisfy ourselves.

Where's my Scotch?

Hi Jack & Chuck,

Thanks or your well thought out and very well written replies.
I think both arguments have merrit and no doubt will be refering to them again.

I had allready committed to buying the several sheets of cheap "blond" structural ply - I bought a few more to cover for my stuff-ups . i will continue with the blond stuff on the practise boat and see how it goes.

I have an almost unlimited supply of wood flour (we call it bog over here) and I'm guessing it will hide a lot of sins.

Can't wait for my ply to get here so I can get started.

Thanks again guys. I would love to do a paddlin trip with the pair of you together - and a liberal supply of moonshing wine.