I’m a great lover of MOLLE backpacks for their convenience and utility, but generally they’re not waterproofed.
Enter “Good Idea” - while I (or more correctly Mrs MD) am putting my other kit through Nik-Wax Tec wash and proofing in the washing machine, how about throwing in the backpack?
All went fine and when dry throwing water at the pack resulted in it going into little balls and rolling off the way it should. Result!
First inkling of trouble came when I got kitted up to tackle the first hill since the treatment… did up the chest strap and the stitching holding the buckles on literally unravelled… the other buckles stayed on, but the webbing slipped easily through the adjusters and wouldn’t hold tight. Consequently, instead of being tightly and comfortably strapped to my upper back the pack hung down against my lower back, bringing considerable discomfort and aches to back and shoulders
My guess is the waterproofer contains something that lubricates the polyester webbing so it won’t stay in place. Will try washing it out of the critical bits, but the pack is showing signs of wear and replacement was nigh anyway. The new one won’t be getting the same treatment :-s
73 de Paul G4MD
Paul, Rustoleum makes a product called “Never Wet” and it sprays on.
A light coating where you need it should work on the "Proof of Concept " pack
I learned years ago that trying to waterproof a rucksack - either via waterproofers or the built-in rain cover - is a futile exercise. Instead, I use Exped drybags to keep things in inside my rucksack. I did have one big drybag, but smaller individual drybags for items is better.
A cheap and effective approach is to use a plastic trash compactor bag inside your pack. Those are about 3X thicker than a regular trash bag. When the bag gets holes in it, replace it.
I’ve only found one drawback. If you accidentally put something inside the pack but outside of the trash bag, you might not find it for a long time.
I bought half a dozen of the small orange Exped bags as they are great for small objects such as keys and HTs and they are very easy to find if you drop one. However I agree with Tom that the larger sizes are essential in rucksacks - a big one in the main compartment and smaller ones in the side pockets.
Thanks for the heads up, Paul, a good experiment!
I use these Karrimor 5l bags https://www.sportsdirect.com/karrimor-dry-bag-784313, which seem to be a good size for eg FT817 + mic, spare jacket / fleece / waterproofs etc.
As well as keeping things dry, they make for a tidy pack, and it is easy to pull out required items without unloading everything as they slip past each other easily. If you do have to take several out, then putting them on wet ground is not a problem. They are colour coded by size, so mine are all orange - a quick squeeze usually reminds what is inside, though
They always seem to be on sale at SD…
Yes all the kit that needs to be kept dry lives in clip-lid food containers (when the mechanical protection afforded warrants the additional weight) or dry bags of various sizes. My main purpose was to try and avoid the 2kg increase in pack weight that I seem to suffer when the thing gets wet :-s May well try one of the localised spray type products to treat the “important bits” next time! I’ll let you know how it goes…
73 de Paul G4MD
In fact, it is highly inadvisable to put a wide range of technical coated fabrics in the washing machine. On the backpacking lite forum they did some experiments with tent fabrics a few years back and found that the hydrostatic head was sometimes reduced by as much as 75% after just one wash. As a rule, the original coating on the fabric is far more important for waterproofing than any after-market treatment. But still manufacturers sell tent wash and wash in re-proofing, which suggests to the average shopper that it is perfectly OK. I have owned several paragliders, and just dragging them over the grass seriously damages the PU coating. The real killer is leaving them in a hot car on a summer’s day when they are slightly damp. The same must surely apply to any silicone or PU coated material. If I do wash things in the washing machine, e.g. membrane waterproofs and Paramo gear, I use a hand wash cycle, 30C temp setting and use spin stop too, so I can take just pump out the water and drip dry them. I would never ever wash a tent or a PU coated backpack in a washing machine. Silicone is, of course, an excellent lubricant, so as shown above, straps will be affected; might help the zippers though.
de OE6FEG / M0FEU