No Spam wrote:
"Tinkerntom" wrote in message
oups.com...
Hey Wilf, You never said that I can find, what sort of roof rack do
you
have? Is it a Commercial unit? If so, most of them have some sort
of
extender system already made. No point in reinventing the wheel.

The problem with electrical conduit is two fold. First it is steel
and
would begin to get nasty fast when exposed to salt water. Secondly,
it
is designed to bend, which is great in some projects, but you would
not
want it to decide to bend when you have the kayak on it and lifting
other end. It would result in a loud crash, and possibly a broken
boat
or twisted back as you try to keep the loud crash from happening.
Any
of these scenarios being bad.

I think you will also find that the commercial extender systems do
not
extend as far as you are thinking like up to 28". So, though they
use
extruded, hardened Aluminum, which is amazingly strong, they only
go
out like maybe 15". Go out any further, and they don't bend, they
break
right of, and you end up with a similar scenario as above.

So it may be time to go back to the drawing board! You might think
in
terms of Titanium, and then you begin talking real money, though
with
the aircraft industry up there, you may have a cheaper source!

What you need is a material that can take the extended end loading,
you
might think of a fiber glass or Kevlar pole, which could be
extended
out beyond the side of vehicle, and supported in the middle folcrum
on
the roof gutter independent from the existing rack. This pole could
extend across the top of the vehicle and be attached for loading to
the
other end of the rack. Think in terms of a teeter-totter, with one
end
held down, and the other end sticking out beyond the side of your
car.
The right material can carry a significant load.

The right material could even be just a clear of knots, straight
grained piece of Douglas Fir. A hand selected 2x4, from the local
lumber yard. Trees are subject to end loading by the wind, and are
incredibly strong.

When you are done loading your boat, the system will not fold up
all
nice on top like a commercial unit would, but you could pull it and
place inside vehicle, or lash along side the kayak on top.

Now your car begins to look like a kayakers car should look. Check
out
the pictures on Wilko's website, and you will get a better idea of
where this is headed. :-)

My only other suggestion also, is that when you lift the front end
up
on the extension, that you tie a loop of rope around it to act as a
safety to keep it from slipping off the extension as you lift the
back
end. this would be especially important if it is windy, or you are
parked on a slope, which could result in the front end sliding off
or
deciding to take a lesson in "flying like a kite!" and you are
holding
on to the little end of the kite.

I am sort of like a bull, when it comes to loading stuff as you
know
(:-), and I just lift my 70 lb boat onto the top of my Caravan. One
time the wind caught the boat as I had it overhead and did a
windvane
number on my back. I am re-thinking my loading procedure even as I
write this all to you. It is amazing how you get smarter each time
you
try to break something. TnT


How about seeing if you can get a section of Schedule 40 pipe about
3ft long
by 1 1/2 to 2 inches and attach it to the rack (no rust). Then get a
good
length of hardwood dowel that fits inside. It could be very loose
fitting if
you have 3 ft of it inside the pipe. I'm thinking 1 1/2 inch OD pipe
should
work great with a 1 inch or 1 1/4 inch dowel - like you buy to hang
the
cloths up in your closet. Toss the dowel inside the car when done (if
the
paddles fit, so will it). A dowel this size with 3 ft of support
should hold
for most boats. I would think it would hold 100 lbs distributed
across the 2
ft or so you have sticking out. -- Stress test away from the car - I
don't
want to get blamed for a paint job after it breaks ;

The beauty of using wood is you should hear it start to fail before
it lets
go. Unlike the conduit which may just fold-up without a sound.

Ken

Ken, the only thing I would question, is that where the dowel comes out
of the pipe, would represent a sheer line. All the load on the extended
dowel would be concentrated at the sheer line as a breaking force. You
would not be able to take advantage really of the flex of the dowel
inside the tube, to dissipate the energy as a flexing force, and it
would tend to break at that sheer line.

You are right on though about hearing the dowel break.

Another function of the safety line that I recommended, is that if the
extension collapses, the boat would not fall clear to the ground.
Considering the car paint though, it might be equally important to use
some cushions in strategic spots in case the boat fell. You could just
hang a long noodle on the side of the car to take the bang.

or like Cyli indicated, you just don't worry about the paint! TnT