Model Forum / Radio Controlled / Water Models / April 2009

New to the site, this being my first post, and have never dealt with RC
boats before (nor have I dealt with gas).  Very familiar with RC cars
though.

Here's my story:
A while ago I got a new weed eater and kept the old "broken" one
because...well I'm a guy..(Can't throw that stuff away!).  Anyways, its
from a Ryobi weed eater and I disassembled the thing (perhaps slightly
too much) very good and got it real clean.  By taking it apart too much
I mean that I removed the clutch and pull start, right now the flywheel
is off, but that can be put back, as well as the flywheel mount.  The
thing runs great so long as the flywheel is on.  I would guess that its
size is around 25cc.

To continue, I downloaded the plans for the 72 inch monohull offshore
deep vee.  I then scaled them down to 66.6%, 48 inches.  I read
elsewhere that any larger than 50 inches I would lose very much
performance.  I got the plans printed and will start construction
tomorrow.  I have a near unlimited supply of 1/8th inch particle board
and that will be for practically everything except the bulkheads and
runners.

A concern was just raised also that because it was scaled down to
accommodate power that the boat may be too narrow, could this be a
problem?  I am guessing that it is about 11 inches wide at the transom.

I am making this to be as cheap as possible so I will not be buying
rudders or any normal components except the prop and prop shaft.  For
rudders I and rigging up hinges to aluminum rudders.  I will be water
cooling to the max and adding a much larger gas tank.  Everything else I
am attempting to make from older RC car parts.

Pictures will be posted as I go, I already have my exhaust tips set up
and made my own custom intake.

Tips are welcomed!

First question, how would I go about brazing brass?  I am using it for
the exhaust.  It has a melting point ~900* so I am hoping that it can
withstand the exhaust temps.