Should waterproofer/repellant spray be used on sleeping bag bottoms?

[Gipsy]

Just curious, since I have not seen a thread on this? I know the bags need to "breathe". I was just wondering if anyone sprayed anything on the outer "floor-side" of their bags.

[daddytwosticks]

Two of my three bags are Western Mountaineering bags. I have invested quite a bit of change in these (Alpinlite and Caribou). I have never even thought of spraying them w/DWR...however, I'd be a little timid in trying this because of my "investment". When used, they always have at least the pad (and usually more) under them. Interesting idea though...:)

[leaftye]

I don't see how it would do any good. Those treatments help the water roll off the fabric. I suppose you could say it makes the fabric waterproof, but only insomuch as that the fabric won't wet out. Water will still be able to be pushed through it.

I wouldn't bother.

[canoehead]

I don't think it would help much. the nylon without a (backing/lament)would still allow in in. If your bag is getting wet here's a few things you can do.
hole in material etc.. FIX IT
you bring it in, Ie wet clothes etc.. PAY ATTENTION / AWARENESS
Condensation / ice BETTER VENTILATION
Pressure wicking from the floor itself. PLASTIC SHEET BETWEEN MAT AND FLOOR
OR BIVY SACK, WORST CASE. REPLACE TENT.

[Tinker]

Sleeping pads, by nature, are non-breathable (they need to hold air, so sheathed in polyurethane coated nylon or bare closed-cell foam, they will prevent the bottom of your bag from breathing). Whatever side of the bag is against the pad will be prevented from breathing, so don't bother with a treatment. You'll need to air the bag out daily to keep moisture from building up anyway. A few minutes in the morning, and, on rainy nights followed by sunny days, a few minutes during lunch should keep the bag dry. I can't think of a bag that doesn't have a DWR finish on the nylon (it's pretty much standard practice to apply it when the fabric is woven), so this is probably a non-issue anyhow. :)