Help building a 17' long x 50" bottom flat bottom aluminum boat

[Loewman]

I am want to build a flat bottom aluminum boat 17' long x 50' bottom. I am building this out of a sheet of 20' x 8' marine grade aluminum @ .125 thickness. This is going to be a all welded boat. The hull will be a full sheet with the rake ends being the only welds on the hull of the boat. On the inside of the hull I will have 6 braces going longitunal the length of the boat. And 2 braces in the middle going horizontal on top of the longitunal braces making it very strong.

My question is to any one that is smarter than me is the sides of the boat is 20" high and the rake bottom is 5' back. What is the radius or arc of the rake. For a flat bottom boat I assume the rake is long gradual turn up but I want to make sure I am going to do this right. It is not cheap to mess up LOL. Also if any one has anything I need to look out for let me know.

[lazeyjack]

explain your proposed structure, is this what you mean?

[Loewman]

Thanks for your reply.. The rake radius I would like to figure is the bow of the boat. The rake at the bow starts 5' back from the front of the boat. Then continues to turn up to meet the sides at the top at the very front of the boat. The sides of the boat is 20". Thanks

[Loewman]

any one?

[lazeyjack]

If you have a scanner, sketch and post, as it is I cant get my swede around what you want

[kengrome]

I presume you're going to fold the sides up from the bottom since you said the only welds are on the ends. 50" bottom plus 40" for both sides makes 90 inches, shall I presume you're allowing 3 inches on each side for the folds (chines)?

There is no fixed radius required for the bow. You can make it a gradual curve or very sharp, and it can be a simple radius or a variable radius curve. I've posted three drawings to illustrate the differences. They all start at 5 feet from the bow. You may want the finest bow (picture #3) for the fastest boat.

This boat will twist a lot unless you install reinforcing in the proper places:

[Loewman]

Thanks kengrome, That answers my question... The more gradual the curve the fast you can run through the water and mud (less drag). That make perfect sense. Thanks for the drawing !! I will try to post some pics as I go.

[Loewman]

Started out with 20x 8 piece of 5086 marine grade alluminum..



Then broke the metal into a hull with a 20' break.


added longintunal bracing



Then start welding



all it needs is paint



Surface Drive Motor



here she is all done with hydoturf on the floors



thanks boat design forums

[mydauphin]

Great work... How does it run, weight? How much did it end up costing?

[Loewman]

Originally Posted by mydauphin

Great work... How does it run, weight? How much did it end up costing?

well I got it to 27.4 mph.. the hull weights about 700 lbs + 260 for the motor.... it is a round chime boat so she banks pretty good in the turns down the river.... I have $2600 in the hull and $3000 for the motor plus the hydro turf $500. I am having a hard time getting insurance for the boat though. As soon as I mention its homemade the insurance agents run the other way LOL.

[mydauphin]

Really great. Love the boat... You should sell plans and/or Boat. I think you could do well. Good luck.

P.S. If you had to build again what would you do different?

[sdupont1]

New to forum but an avid duck hunter. That is exactly what I want to build also. A one piece bottom hull. My spoolgun just came in yesterday and have been on CAD drawing out things. It has a prodrive boat look but what I really like is the transom (like a gator trax) or step deck. I also have a 35hp hyperdrive mudbuddy. Do you happen have a material list and some more pics?

[johngilpin]

Hi All

How about this style.
16' Aluminium tiny under construction.


Kind Regards

John

[jchance]

Loewman,

Can you please contact me by email? My address is adam.chance82@gmail.com