View Full Version : sil coated nylon for stuff sacks
I have seen in various places advertisements or listings for sil coated nylon stuff sacks and other items. Does sil coated nylon make something completely waterproof? somewhat waterproof? If I have a down sleeping bag in a sil coated nylon stuff sack in pack and its raining...would my bag stay dry?
i have an oversized silnylon pack liner,i put all my stuff,food,hammock sleeping bag in sinylon stuff sack,they are light,cheap,and i never have had anything get wet,it works for me:cool: neo
SGT Rock
05-10-2005, 02:54
Well almost nothing is 100% waterproof. I'm not a fabric expert, but as I unestand it: Silicone impregnated is better usually than sil-coated because sil coated can eventually delaminate. Sil-coated is a cheaper material since the process to coat is easier than the impregnation process.
Like the Rock says, probably not 100% waterproof, but very good. You can buy pack covers made with sil nylon.
JoeHiker
05-10-2005, 08:56
Well almost nothing is 100% waterproof. I'm not a fabric expert, but as I unestand it: Silicone impregnated is better usually than sil-coated because sil coated can eventually delaminate. Sil-coated is a cheaper material since the process to coat is easier than the impregnation process.
Does anyone make silicone impregnated stuff sacks? I assume that the term "sil nylon" always refers to sil coated, not impregnated, is that correct?
tlbj6142
05-10-2005, 09:04
Nope. Almost all silnylon you see on the market is the impregnated stuff (espeically stuff sacks, sil-ponchos, sil-tarps, sil-tents, etc.). Coated silnylon is heavier 1.9oz vs 1.4oz.
In fact, I'm not sure I've seen sil-coated nylon even mentioned much lately. Sometimes you see it used on home-made lightweight packpacks and (I think) Six Moon Designs still uses 1.9oz coated stuff for the "heavy duty floor" option on his tents.
Youngblood
05-10-2005, 09:43
I'm getting confused. I thought there was silicone impregnated 1.1 oz rip stop nylon (aka silnylon) and the heavier polyurethane laminated 1.9 oz rip stop nylon that are commonly used for stuff sacks. Either one can leak at seams and openings unless they are specifically constructed to be waterproof, ie dry bags with more complicated seams and roll top closures.
I think the answer to the original question is that a stuff sack (silnylon or otherwise) for a sleeping bag is not all that waterproof by itself. Usually folks line the sleeping bag stuff sack with a plastic garbage bag and this arrangement keeps it waterproof enough to keep your sleeping bag dry inside your pack when it is raining. I have always used the stuff sacks provided by with the sleeping bag because it is the recommended compressed size and it is strong enought to stuff the bag into (1.1 oz silnylon is not as strong and it is hard to hold onto a slippery silnylon stuff sack when you have to cram it to maximum capacity)... I just line it with an appropriately sized plastic garbage bag and put it into the bottom of my pack which often gets damp even though I use a pack cover.
Youngblood
tlbj6142
05-10-2005, 10:06
I'm getting confused. I thought there was silicone impregnated 1.1 oz rip stop nylon (aka silnylon) and the heavier polyurethane laminated 1.9 oz rip stop nylon that are commonly used for stuff sacks. They also make a Sil coated 1.9oz nylon.
Either one can leak at seams and openings unless they are specifically constructed to be waterproof, ie dry bags with more complicated seams and roll top closures.Very true. And, of course, you can't submerge silnylon stuff sacks either.
I think the answer to the original question is that a stuff sack (silnylon or otherwise) for a sleeping bag is not all that waterproof by itself.I use trash compactor bag (think thicker kitchen sized trash bag) and put my bag and some of my spare clothes (usually just my down jacket and sleeping socks) inside the trash bag. Squeeze out all of the air I want removed, roll the top down and place my food and other gear on top. I don't use a pack cover, and don't trust a stuff sack alone to keep my sleeping bag dry.
RockyTrail
05-10-2005, 10:14
I've had good results (not got the bag wet) using an Outdoor Research No 3 stuff sack to pack my down bag (marmot pinnacle). I use an external frame pack and the bag is lashed to the lower frame and the whole pack has a good pack cover.
The OR sack is very strong (like YB said it needs to be tough for compacting) and the seams are taped internally. It's almost a dry-bag type construction except without the fold-over top. The sack material is regular nylon, but the inside is a white plastic layer that reminds me of the inside of a refrigerator. Don't laugh, lack of food will make you think that!:D
Up to three days of continuous rain while hiking (fun trip ha ha) hasn't got the bag wet yet although the damp air makes everything a liitle bit damp. I don't use a trash bag liner, but I might try it sometime. The OR bags are tough and work for me...
peter_pan
05-10-2005, 11:07
Silicone impregnation is just that...impregnation...thru and thru....both side will feel the same....it will not peel off with time as urthane coatings do....it also adds a little less weight than the coatings...
As to weights 1.1oz ripstop when impregnated weight between 1.34 and 1.4 oz ...it is often referred to as 1.35 silnyl or 1.4 silnyl...
There is another small block nylon that looks like 1.1 oz ripstop that is actually 1.6 oz .... the only way to normally tell it apart is to actually weigh a couple of square yards...if impregnated to make silnyl it will become 1.9 or there abouts....This is different from 1.9 oz ripstop which becomes 2.2 oz if impregnated...Hope this helps.
Pan
peter_pan
05-10-2005, 11:15
As to slipperyness...and waterproofness ...IMHO ...silnyl makes great stuff sacks and compression sacks...there are growing numbers of them available....the weight savings of 1-2 oz per bag adds up to 4-6 oz per pack...and they are waterproof and a lot less prone to tears than plastic bags...Have been using them for all my gear for over three years....have received a report from one of our customes in Australia who lost a pack in a river and when it was recovered the quilt in the silnyl compression sack was totally dry...
Pan