Twistedteddy

So i ahve some materials to make a blow boat. i have an asp engine that im gunna break in on it for my airplane build. and can replace later. but im pretty sure i can get the boat done in like 2-3 nights. the plane is a several week project. i was planning on using coraflute for the skin and DOW Styrofoam insulation board for the main hull. but idk what size it should be or anything? Im gunna use my asp .12. Any help would be greatly appreciated. Thanks and happy boating!

Altered1

Roughly speaking, the hull needs to be 1/2 as wide as it is long.  You'll want the balance point approx 1/3 of the length, from the transom.  I'd suggest you try to build a flat bottom before you go for a hydro.  Angle the sides at 30-45 degrees and she'll slide nicely in the corners.

I cant help you on size... I've got a 900mm x 450mm  body board hull, powered by a .52, and she's fast enough to keep me on my toes.  But I'm just learning as well.

perhaps one of the more senior members could advise.... 

71dartswinger

my first one is 24x12 with 45degree sides and runs good with a fox .25
so your smaller motor might do on a 18x10 the plans i used are on cajun gator site

Twistedteddy

I got bored last night and made this. i didnt put an angle in the sides but hst just means it wont slide right? which would sketch me out about ti[ overs. im prob gunna use a water rudder. but if this hull needs the sides angled i can always modify it. its 221/2 inches long 16 inches wide and 43/4 inches deep. watertight thanks to its hot glue constructiong lol! it only took about and hour to make just dilly dallying. at first i thought the size was too big. but its soooo light that i think it should work just fine. im prob. completely wrong but its just the first attempt. let me kno what u guys thinik.

Altered1

Oh, It will slide, just not as well...   but if you use this as a learning experience, you can take the lessons learned and apply it to the second build, which I guarantee you will want to do !

I reckon you have made the hull too deep, probably only need an inch or so at that size. 

air rudders would be easier to setup, and with a water rudder, she'll definately handle like she's on rails - no sliding at all!

don't forget to waterproof the electrics!

dadkins

Looks a little big to me. I have a .15 motor that I had on a 8" w x 14" long that was pretty cool.

Twistedteddy

you kno the size thing i wasnt sure about, and i can hack the sidesw down, the thing with the size is thats its reeeeealy lite. so i figured it would go fine. ill modify this one throw an engine on it and see if it works. if not, ill make a new one. only takes a few hours. all else fails. BOOGY BOARD! but im a builder. so thats what ill try first. and for water proofing? im getting tupper ware containers. thank you for the replys. i could use all the help i need.

Altered1

Now worries TT,

The size is not really an issue just yet - it just doesn't need to be that tall.... you can leave it for now.   But just for kicks - throw it in the bath, add the engine, and batteries and some more ballast to simulate a complete build, and you'll get a better idea on how thick the sides need to be. 

Tupperware will do you fine, but a full size boogie board will be too big for the .12... unless its a kiddy pool toy size board, which may just work for you.

Get the engine on your current hull and see how she goes.  Have you though about how to build the engine mount ?  where are you going to place the fuel tank ?  easiest running if the tank is level with the carby.

good luck

Twistedteddy

for the engine mount im prob gunna use a few peieces of spruce or something. and the fuel tank its prob gunna be right behind the engine on the same platform that the motor mounts too. and ya im gunna have to cut the sides down by a bit. iv been workin on my airplane and kinda plateaued on it so im gunna hop back to the boat. thanks again everyone for your replays.