Thread: where to start

You'll need to post your file in a format most of us can use mate. Maybe a jpg (do a screen dump to MS Photoeditor or similar).

Good project. There's nothing to fear in flat bottomed boats for this purpose - eg Mik's Handy Punt.

Richard

done through paint- how do i do it so you guys are able to edit etc

Thanks Jeremy. I can see that

I'm no designer so you need to take that into account (ie, listen at your peril ).

I wouldn't have thought you needed 9mm on the bottom, 6mm is pretty tough stuff.
As per PDR (the Puddle Duck Racer - see the Storer sub forum) standards, you could probably use 4mm for the sides too but 6mm again would make for a solid boat (the rowing skiff I'm building is 6m all round).

The rear transom can be made lighter by using 6mm ply with some framing to beef it up or even two layers of 6mm with some framing. You'll need knees (gussets) in each corner to hold it all together.

The sides look very high - is that a trick of the perspective or have you allowed for a lot of freeboard? Bearing in mind that these things float on nothing, you might just be adding windage (the side of the boat working as a sail).

The curve under the bow would be really 'interesting' to make. The PDR and the Handy Punt both get away with a straight bow and my thoughts are that you're best off doing the same if only for simplicity's sake.

Have you made some measurements on motors to define the height of the transom? I can envisage an interesting part of your report discussing long leg motors vs short leg and the effects on that transom cut out.

The layout looks good. You'd need to position that central seat to balance the boat of course. How are you working that out? Just by eye? Comparitive measurements? Do you have a program that calculates how the thing balances?

You can actually position the centre seat by trial and error. Make the boat water proof, plonk it in your mum's swimming pool, and sit on a box. Move the box backwards and forwards and when it's trimmed properly, build the seat there. This isn't as rough as it sounds - read this article from Jim Michalak on rowboat setup.

Have you considered how the parts will fit into your sheets of plywood? With ply in the order of $100 a sheet (depending on type and thickness), the trick is to use as few sheets as possible while reducing the amount of waste. You'll need to consider ALL the bits - seats, etc.

Good on you for having a go mate. You've made a good start. I'm sure some of the real designers on the forum will come on and contradict me somewhat but I applaud what you're doing and reckon you'll have a lot of fun with the build and the fishing

Richard

I assume those seats are boxed in with the ply. Add a font seat or a front buoyancy tank under that deck and it will be pretty good structurally.

Boxed in areas are really useful in structural terms to prevent the boat from distorting under various kinds of loads as well as supporting the bottom.

The ply thickness that Daddles is mentioning is right for a row or sail boat. But a motor boat is going to get more power stuck on the back by someone at some time so the bottom had better be stiff and strong to allow for that to happen.

Best wishes
Michael

daddles
6mm all around is good, i forgot the back braces in the back corners, instead of using 2 6mm ply i could just use a 12mm. Concerning a sraight bow do you mean instead of being a curve, just have 1 board for the floor then a for the 'curve and then for the wave breaker part. There is 300mm freeboard, this should allow enough for setting nets pots etc and general fishing. In regards to motor height (short shaft and long shaft), i can easily go into shed and pick 1/3 motors and check it out. motor will definatly be short shaft (lighter etc better for this kind of use).
Dont have program for layout (never knew you could get one) Seat layout is by judgement and eye. to do pool method i would have to make it and then take home then take back. how would it work waterproofing it and then drilling the supports for the seats in. With the plywood situation, sheets come in 2400 x 1200, width fits perfect, if i was to still have curve how could i work it all, however if i was not to have curve i could use a new sheet and use excess for seats etc. how would i join the bottom to where the curve used to be? i'm definatly climbing out on a limb with this project

Mik
yes the seats are boxed in with ply, do you mean on the bow under that section?

Originally Posted by thebullfrog07

With the plywood situation, sheets come in 2400 x 1200, width fits perfect, if i was to still have curve how could i work it all, however if i was not to have curve i could use a new sheet and use excess for seats etc. how would i join the bottom to where the curve used to be? i'm definatly climbing out on a limb with this project

Mik
yes the seats are boxed in with ply, do you mean on the bow under that section?

I think you are very much on the right track.

Yes .. to box in under the foredeck even if you have an access hole in the back face will help stiffen the whole bottom in that area too.

To join the ply you either use a 6:1 scarf joint or a Butt Strap of the same thickness as the bottom ply that is the length of the join and 20 times the plywood in width. Keep the joins in the flat section of the boat towards the back.

Best wishes
Michael Storer

Do you think it also needs some stiffening in the gunwales to resist lateral flexing & distortion?

If the fundamentals of the hull skin and holding it together are OK then stiffening details can be sorted out later. There is a good argument for going small with such pieces then increasing the sizes down the line if there appear to be problems.

The basic Structural requirements for joining bits are set out here ...
http://www.storerboatplans.com/wp/?p=474

For stiffening items there is not rule of thumb, so you need to work out what is needed.

MIK

thanks guys are scarf joints and a butt joint hard do you have link to butt joint (it sounds hard)

Did you see the diagrams in my post above. The Butt Join is dead easy.

MIK

yeah, but if i am having a straight rise and not a curve in the bow, how dod i join the wood then?

I am not sure what you mean.

If any of the big panels of the boat are longer than 8ft they will have to be joined and the buttstrap or scarf are the available methods. You can do other sorts of join like glassfibre joins but they are more messing about particularly if you are wanting to match the strength of thicker plywood.

You might be talking about the bow transom - the sloped front of the boat that meets the bottom panel. You can put a piece of timber in that corner that has the right bonding area to both the bottom and the bow transom and it will be fine. Do a drawing and you will see how big and what shape it has to be.

Not sure If I understood what you meant so covered two of the possibilities.

Best wishes
Michael

[QUOTE=thebullfrog07;1093702]okay,t will be purely for fishing and using a motor/rowing (up to 5 hp-use of alternater thing used to charge lights) and for floundering. it shall be beach launched most of the time.

Hi Jeremy, The term Floundering is something I haven't heard for some time, then I noticed you are from Tassy, As a young boy I spent many hours floundering around the Rubicon River (Port Sorell). We had no money (just like now) so we made are own spears, borrowed the battery out my fathers police motor cycle and used recycled car head lights to find the tasty flounder. We would srtap the battery to an old tyre tube and drag it behind us as we wandered over the beautiful sand banks.
The idea of building a flat bottom punt is quite sound, but I will leave the building advice to the experts on this site.
I was lucky enough to team up with another kid who had a home built mirror sailing dingy, so by day we would go sailing and at night fish. This may be worth considering.
Good luck with your project
Ian L "Wavedancer"