Painting aluminum glider trailer

I have lived in Texas most of my life and can tell you from experience
that my trailers will ALWAYS be white. On bare aluminum, use a solution
of 10/1 water/white vinegar to etch the surface. Rinse thoroughly and
use alodine per lable directions. A good quality, latex gloss
housepaint can be rolled on with a low-stipple mohair roller and the
results look sprayed. This paint, applied properly, will last 15 years.
If you're in a dry climate and have some shade for it... it'll last
much longer than that. No primer, no spray equipment, and a decent
paint job for less than $200.00. Who could ask for anything more?

Jack Womack

Thanks, Fernando. Just two illustrating examples which everybody knows:

In winter, a metal table feels colder than a wooden table of the same
temperature, because metal conducts heat much better then wood.

In summer, you burn your feet by walking through hot sand a the beach,
but not by walking over wood of the same temperature. Same reason.


BTW, this is also the reason why it's no big deal to walk over red-hot
coal, especially if you walked through wet grass before. If you try it
with Charcoal, that is. But please don't try it with mineral coal!

Stefan

A mistake in my previous posting: white paint has a solar reflectivity =
of 70 to 80%. It is the opposite property of solar absorptivity, from a =
table of which I was quoting, that is 20-30%. I hope the argument makes =
more sense now.

If you are looking fo a cheap job (cheap is emphasised,
no flames please) you can paint aluminium with an ordinary
roller and household gloss, eg Dulux enamels, I hope
Dulux is recognisable in the USA.

Yes, I do know that if you're going to paint Alu properly
then you use epoxy etch primer and a decent topcoat,
but the raw materials alone are still going to be about
400ish dollars, trailers have a big surface area.

Compare this with 10 litres of household gloss, no
flames please, this is a cheap suggestion, it works
and has lasted for 5 years so far.

John Murphy wrote:
I have a 20+ year old trailer for my G102. Presently, its bare sheet
aluminum. I want to paint it white to reduce the amount of heat
absorbed by the trailer skin. A local autobody shop quoted me $1600.00
to cover with a polyurethene paint over an epoxy primer. This is far
more than I wanted to spend. Any suggestions on durable paints or
products that can be applied by a novice to sheet aluminum. I can rent
an airless sprayer if need be. Thanks.

I looked into this when I had an aluminum tube-type trailer. I compared
the air temperatures inside the trailer in several places (ceiling,
floor, inside cockpit) with those in a similar trailer painted white. As
I recall, the air temperatures in the top 6" of the trailer were 10 to
15 F hotter, but below that, the air temperatures were only a few
degrees hotter. Because the _glider_ temperatures were hardly different,
I decided the heat protection gained wasn't worth the cost and effort to
paint the trailer.

I believe the hot air convects to the top of the trailer and insulates
the rest of the air from the heat input. I notice the same effect in my
Cobra trailer, where the air near the top is very hot, but below that
the air is only a few degrees above the outside air temperature.


--
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

I painted my trailer with white two part epoxy paint. It was about
$110 for two gallons (a gallon each of part A and part B). I went
through about 3 gallons total. I mixed the first two gallons together
and when that was gone, 1/2 of each of the other two gallons. Thus I
have some left over. I put it on with a short nap roller. Looks
great.

You can't generally find this at the big box stores and have to go to a
paint only storefront that the trades use. Epoxy paint can be sprayed
but cleaning up the sprayer afterwards could be tricky.

Funny story: the counter guy at the store admonished me to not mix the
two together unless I was ready to paint. No duh. Apparently a guy
came back to the store after buying some epoxy paint holding a bucket
of now quite hard paint with a stiring stick permanently stuck in the
middle of it and wanted his money back. Uh huh, yeah, sure. Read the
label dude.

- John