lightweight jon boat

[SnowyK]

Hi Guys,

This is my first post so bare with me;

I am interested in constucting a lightweight 11ft jon boat (Storer Handy Punt) that can be easily transported on vehicle roof racks. Boat will initially be powered by a 6hp and will be used in sheltered waters only (may install 10 - 15HP at a later date).

I have not previously built a boat but have worked with polyester before modifying the internal layout of other vessels I have owned. I have no experience with core materials and am wondering if it would be possible to use honeycomb like nida core to construct rather than ply. If so;

- how would it compare to Epoxy / Gaboon plywood with regards to weight, strength and longevity?
- What type of resin should be used?
- what type of mat / cloth should be used and in what lay up?

My objective is to build something that is lighter than 50kg but still retains some degree of robustness to take the knocks and bumps that inevitably occur when car topping. Needs to plane with 1 - 2 75KG adults aboard and 6 - 8 HP.
Cost is a consideration, but is secondary to weitght and strength.

Cheers

[hoytedow]

I would NOT recommend putting over 8 horsepower on an 11' jonboat. You can keep it light, but the lighter it is the weaker the skin of the hull will be. Having said that, a hull of 1/4" plywood taped at the seams with fiberglass then fiberglassed all over will be strong and not overly heavy. This should come in under the 50 kg ceiling you have stated. There are seveeral forums within this site from which you can gain invaluable information on building techniques from some very gifted designers, both professional and amateur. Good luck!

[PAR]

15 HP is possible on that little boat, but it will pound like crazy when lightly loaded or in chop. It would be wise to increase the bottom panel thickness to the next size if 15 HP is you plan. I'd recommend 10 HP with your requirements.

Most of your questions would be better answered on Michael's forum (the guy that designed the boat). http://www.woodworkforums.com/forumdisplay.php?f=169

Tell them PAR sent you with questions.

[hoytedow]

Yes, what PAR said, and beef up the transom , too, as it will be hanging more weight and greater stresses. Bear in mind you will probably put it over the 50 kg weight limit.

[SnowyK]

Thanks for the feedback guys.

I will do as Par suggested and post some questions on Michael's site. I Intend to stick with 6HP initially as I have a 2 yr old Suzuki DF6 already. I am well aware of the limitations of this style of boat and have no intention of using it in anything other than small rivers and creeks (no chop) as I have a larger boat that I use to fish bays and more open water.

No problem with using epoxy and ply, but was just curious to know if there were significant weight savings to be made using other core materials as I will be manhandling this thing on and off the roof of my camper trailer.

Cheers

[PAR]

There will be no significant weight savings with core materials in a boat this size, without falling back on high tech fabrics and costly cores. This assumes the same strength to weight ratio of course, not to mention the cost per pound.