scouts-l Mail Archive for May of 2000: Re: Waterproofing Canvas
Wed May 24 2000 - 06:08:52 CDT
In a message dated 5/23/00 10:06:53 AM Pacific Daylight Time,
> I have several 1/2 shelter military tents that we are using for the scouts.
> For summer camping, which is almost all year round, they are great. During
> a rain storm, however, they do leak. Does anyone have any great ideas on
> treating the canvas.
Ahhh, shelter halves. I still have the pair that I camped in as a scout back
in the early 60s. No military shelter halves that I've seen were ever treated
for water resistance.
As cotton canvas gets wet, the fibers swell. This swelling closes the pores
of the fabric, making the tent very rain resistant. However, if one touches
the inside of the tent, water will wick through the canvas at that point,
creating a steady downpour. The trick, then, is to avoid touching the canvas.
How do you do that inside a cramped shelter-half? I dunno.
Many older nonmilitary cotton canvas tents had a wax treatment for
waterproofing. However, this would greatly increase the flammability of the
fabric. Cotton normally burns quite slowly, giving campers time to escape.
The wax would be disastrous. Don't do it!
ScotchGuard might be an alternative. I don't know about its flammability when
dry -- you'd need to test it on a scrap of canvas. I've heard that
ScotchGuard is being removed from the market because of its effectiveness as