The factory version (www.roadshower.com) linked to in the Samba posting
has a pressure relief valve possibly for expansion when hot? but I can't
imagine that the thing would get so hot from sitting in the sun that
pressure could be a problem. Pressure is, in fact, desirable: the
factory piece has a Schrader valve on it so it can be pressurized,
either from a CO2 cartridge or a tire pump.

But the factory version is not just a hunk of black PVC pipe: according
to the web site,

"Road Shower uses the renewable energy of the sun. The sun enters the
clear chamber and heats the black surface on the inside which heats the
water. The clear chamber is critical for heating the water....the water
will not heat up much if you used just a black pipe.   The  water
temperature rises 6-8 degrees per hour on a warm sunny day. If your
water starts at 60 degrees, it should be 90+ degrees in about 5-6 hours.
On a hot sunny day the water can exceed 100 degrees. If you fill the
Road Shower in the morning, it should be warm by mid afternoon. It heats
up while you are driving down the highway, 4 wheeling, or parked
somewhere in the sun. The Road Shower does not heat water as well if the
outside temperature is below 70 degrees and/or the sun is low in the
sky, or during cloudy days."

Still and all, I think something like that would be pretty handy.

That said, I like the idea of using engine heat to heat a tank of water
for showering, but unless someone has some handy kit to sell, I think
building one out of spare parts found in the basement might be
difficult.

--
Rocky J Squirrel

On Sun, 2010-09-12 at 18:24 -0700, Alistair Bell wrote:
> On second look, I wonder about pressure increase in tube when water
> heating, not a big concern I think. Oh and you need a vent to allow
> good water flow...
>
>
> No way will you get me storing my rods outside of the van :) Awing
> poles yes.
>
> alistair
>
>
>
>
> On 12-Sep-10, at 6:04 PM, Don Hanson wrote:
>
> I bet that works fine.  Looks to me like a person could configure
> something
> like for double duty, also.  Carrying fishing rods?  Store your awning
> poles?  Then when you got somewhere for a day or two and had the
> other stuff
> out, just fill it with water.
>    Don Hanson
>
> On Sun, Sep 12, 2010 at 5:14 PM, BenT Syncro <syncro@gmail.com> wrote:
>
> > Here's the unbroken link:
> >
> >
> >
> > http://www.thesamba.com/vw/forum/viewtopic.php?
> > t=431812&sid=4e2da8cfea50e637aed82cf668a0b313
> >
> >
> > BenT
> >
> >
> > On Sun, Sep 12, 2010 at 4:43 PM, Alistair Bell <albell@shaw.ca> wrote:
> >> On the samba
> >> http://www.thesamba.com/vw/forum/viewtopic.php?
> >> t=431812&sid=4e2da8cfea50e637aed82cf668a0b313
> >>
> >> It has its merits.
> >>
> >> alistair
> >