Mini Jet Build

[WebsterCityIowan]

Hey guys,

I haven't been here in a few years but I figured that I'd drop in and seek some advice. I am totally new to the boat design/building process, although I did document a restoration here in 2010-11.

Anyway, I am currently working on designing an all aluminum boat that will be suitable for river usage. The basic portfolio will be approximately 14 feet long by 60 inches wide. I am fairly certain about this size as I plan on using the boat to reach remote fishing spots on interior rivers. More specifically, I plan to use this boat to reach said locations and then wade to the actual spot, I do not plan to fish out of the boat at all.

I'll post some screenshots of my ideas later when I re-learn photobucket. Moving on to the the design, I have decided on (thus far) a 12 degree dead-rise hull with a sort of "modified-V" bow. I am set on a closed bow configuration with either a bench style seat or two "racing" style seats. After doing some research, I think I would like to use an 1100 CC Yamaha engine along with the pump, which I would likely source from a PWC. I'm planning on using 3/16" for the hull and bow, with 1/8" for the top, sides, and other non-structural features. 5052 H32 will be my alloy of choice.

Honestly, I don't know how long this project will take. I am currently a senior in college, about to start my final semester. With that being said, I do not have a lot of free time after work and school are taken care of. However, designing and building my own mini-jet has been on my list since I started fishing primarily rivers about 4 years ago. I am open to any and all criticism, thanks in advance!

 

[GA_Boater]

Big endeavor. Designing and building a boat from scratch takes a lot of work, money, space, tools and metalworking equipment.

I've seen some jets that used an aluminum utility or jon boat as the basis and they've turned out pretty good. All the design and assembly was done by the manufacturer and a jet from a PWC supplied the engine and jet drive. Doing something along those lines would be much faster than starting with a blank sheet of paper. Some food for thought.

 

[gsxrdan]

I love the concept, and want to do the same myself. There are some great mini jet designs from new zealand, i spent hours watching footage of the crazy kiwis bouncing their boats over the rocks and rapids, driving in only a couple of inches of water! But being completely lacking any alloy fab skills, i want to do as don said above, and convert a small 'tinny' with a pwc drive unit. Most of the kiwi mini-jets have the entire jet unit protruding from the transom, like a stinger, therefore allowing the engine to be rear mount. prob best to have a bench seat so you can keep the cog over the keel when driving solo. Good luck with it!!

 

[WebsterCityIowan]

I love the concept, and want to do the same myself. There are some great mini jet designs from new zealand, i spent hours watching footage of the crazy kiwis bouncing their boats over the rocks and rapids, driving in only a couple of inches of water! But being completely lacking any alloy fab skills, i want to do as don said above, and convert a small 'tinny' with a pwc drive unit. Most of the kiwi mini-jets have the entire jet unit protruding from the transom, like a stinger, therefore allowing the engine to be rear mount. prob best to have a bench seat so you can keep the cog over the keel when driving solo. Good luck with it!!

Thanks! I have no shortage of fab skills...boat design skills on the other hand....All of the fab work should be simple, I have a ton of specialized equipment at my disposal.
I thought a lot about modifying a flat bottom but I worry about their rigidity...plus this way is more fun! I'll try to upload some screenshots tomorrow after work. I'm currently using Fusion 360 to model, though I may be getting Solidworks in the near future. It has more features that will be useful for this project, especially in the analysis department.

 

[Scott Danforth]

plenty of mini jet boat builds on youtube.com many coming from NZ.

if your going to run skinny water, will you be lining the bottom of the hull with delrin?

using 3/16" for the hull would be overkill. heck, basstracker only uses 0.090" on the old units and they were battle tanks. with proper ribbing and chines you should be able to use 1/8"

https://www.youtube.com/watch?v=9-CYx8_QCII

https://www.youtube.com/watch?v=WtE2ESpIAp8

https://www.youtube.com/watch?v=1AeuJyBV2YA

http://www.nzjetboating.com/yabbse/index.php?topic=23617.30

 

[proshadetree]

I like the ideal of the mini jet boat but have you considered the air boat instead? Those things make enough boost to drive on grass. Dont know how they would do in your fishing location though.

 

[WebsterCityIowan]

plenty of mini jet boat builds on youtube.com many coming from NZ.

if your going to run skinny water, will you be lining the bottom of the hull with delrin?

using 3/16" for the hull would be overkill. heck, basstracker only uses 0.090" on the old units and they were battle tanks. with proper ribbing and chines you should be able to use 1/8"

https://www.youtube.com/watch?v=9-CYx8_QCII

https://www.youtube.com/watch?v=WtE2ESpIAp8

https://www.youtube.com/watch?v=1AeuJyBV2YA

http://www.nzjetboating.com/yabbse/index.php?topic=23617.30

That is good news to me about the 3/16" being overkill. I've already modeled most of the hull in 3/16 so I'll finish it then do it again in 1/8. Then I can compare the theoretical weights of the two. I don't plan on lining the bottom, mostly due to the fact that most of the rivers around here are full of silt, not rocks.

 

[archbuilder]

Interesting project. I don't know a lot about tinnys, but 3/16" does sound really thick! Looking forward to seeing what you come up with!

 

[ondarvr]

Sometimes they're at 1/4", just depends on where and how you plan to use it.

 

[redneck joe]

I would not this a pwc motor in shallow water would be good, woulnt it suck up dirt mud and small rocks? Not my area of expertise