zedteamk2

Well, i've wanted to build one of these since i was a little kid, and have even drawn up some rough plans.
What are you guys building these boats out of? i am familiar with balsa wood, but it doesnt seem like it would be very robust. I'd like to be able to build something i can bang around a bit

I have the remote, servos and receiver from a R/C car a built a long time ago and was planning on using those. Will they work fine?
The engine that i have is an OS Max 40 SF ( not really sure what that means ) brand new but at least 15 years old .

What size boat should i be aiming for with an engine that size?

What materials do you use to mount the engine?, would some type of wood be strong enough?

Thats all the questions i can think of for now, but i am sure i will come up with more.

Thanks for the info !

saleens7

its a .40 size engine....

i would thik its best to build the boat from insulation foam or wood....1/4" ply for the internal structure and motor mount and you could use 1/8 ir 1/16" birch ply for the skin.....for the foam, its best to fiberglass over it, but if you do, remember to use epoxy resin, poly resin will melt foam....if you build a wood hull, you could use poly or epoxy resin.....i would guess the hull could be anywhere in size from 22x11 to 28x15..its usually best to have a 45 degree angle on the sides, that way you wont have a sharp side that can catch the water a flip the boat, but instead, you can slide sideways on the water.....for the motor mount, 1/4 ply should be strong enough...it also goo to have the hull between 1.5"-3" thick....2" thick seems to be the norm though...

boatman1

Well i'd try some coroplast for a fun rugged tuff airboat hull
My first coroplast airboat has lasted 6 gallons of fuel & it
still floats ,its been Drivin all over the place by many people
i even drag raced a few rc cars & trucks with it at one time & won a few races even lol

rough size hull 14x 24

some alumin & 1/4 plywood for motor stand

jasperrc

All good advice...

You might check out the RC airboat gallery at [link=http://www.rc-airboats.com/gallery/]www.rc-airboats.com/gallery/[/link].

Lots of great examples and ideas out there including some well detailed builds.

zedteamk2

Is coroplast the stuff they make signs out of ( looks like the plastic version of corrugated cardboard ) ?

Mr Cajun Gator

[link=http://cajungatorairboats.com/v-web/bulletin/bb/viewtopic.php?t=54]40 size airboat plans[/link]

jasperrc

Yes it is. So far all of my boats have utilized coro as the primary building material. I like it because it's cheap and easy to work with.

But like everything, it has advantages and disadvantages. It is more susceptible to cuts and small punctures in the hull due to sharp rocks, etc. But you will never see it crumble, crack or buckle due to impacts with large rocks, or even other boats like you can with foam or even wood. It's also waterproof as is.

Foam is nice because you can make it into any shape you want to. Just cut away everything that doesn't look like your boat. It's light and has built in bouyancy. Unfortunatley it is susceptible to cracks and breakage with hard impacts. It also requires sealer (resin) like Saleen suggested.

The advantages of wood are pretty obvious. It's a strong, readily avaliable material. It's much more puncture and cut resistant than coro or foam, but does need to be waterproofed. It is also susceptible to cracks and breakage with heavy impacts, and it typically requires more specialized tools to build with than foam or coro.

RS 38-40 built a great coro boat using plans similar to the ones Mr Cajun Gator has posted a link to.

Here's a link to another set of plans as well. [link=http://rcairboats.net/phpBB/viewtopic.php?t=190]Simple flatbottom plans[/link]

The thing to do is be creative. If you can't wait to get on the water, maybe grab a boogie board and mount a motor on it.

I hope this helps some. Happy building!

zedteamk2

I think i am going to go with basswood for my hull. Due to it being easy for me to get, and i allready have most of the tools to work with it.
As far as design goes, i am probably going to use the basic cajun-gator model, but add angled sides.
Another question....
What do you use to seal the wood from the water?

jasperrc

Probably the most common sealing materials for wood are those mentioned by Saleen, epoxy resin, or poly resin. Both work well. Poly is generally more readily available and cheaper but will eat foam. I've also heard that it's more brittle than epoxy, but I haven't tested that myself.

ISIRC10

BASSWOOD[X(]!!! It's so expensive (where I live) and it is pretty soft. I made my first boat out of two 2x4s (pine) and did a bit of routering and hand finishing. It took pretty long to do but worth it in the end. IMO to seal the wood I would paint it and then use a clear spray can laquer to finish it off. good luck!!![8D]

zedteamk2

by 2x4's do you mean the stuff you build a house out of? that seems kinda heavy.
basswood seems cheap around here... 50cents more ( ish ) than balsa wood of the same size
What is there that is like basswood ( it seems easy to work with ) that is possibly harder or cheaper?.
I am pretty much stuck on the idea of using wood of some kind because that is what i am used to.

would Sig SuperCoat be a decent sealant? , it's basically dope that you use for applying tissue paper to model planes.
My plans are coming together now with all this great advice ! thanks for helping a noob
I would like to just use a clear coat over the wood because i like how the wood grain looks

Thanks again for all the help

P.s..... if there is some FAQ that i should be looking at that explain all this stuff, point me in the right direction and I'll leave you guys alone

ISIRC10

Yep, you got that right. they were extremely heavy at first but now they weigh less than a pound!
The two blanks-about 5 pounds

A little bit of routering-about 3 pounds

Finished product-Less than 1 pound

All in a days work!!![sm=spinnyeyes.gif]