Alpacka Cargo Fly drybag inflation – moisture management question

doesn't yer stuff just go the cavern, and then you pump up the raft, so the container area gets smished ?

i dunno .. that's how it looked to me on their website.

v.

um…not sure i understand the comment but no you are supposed to inflate both the raft as well as the dry bags. anyone on the forum who has one and can comment?

Elliot
You might find some useful info in the comments of this thread I started on modifying Alpacka inflation bag to inflate a neo-air. http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=75655

James, that's great! very helpful, thank you.

el, the down in your sleeping bag and garments do have a dwr shell over them so I'm not sure if breath condensation will do too much harm if any. especially if you are expressing air as you create the airtight seal. dont know for sure. maybe test it out at home or someone more qualified with experience can chime in.

also, I have an extra instaflator if u need it buddy

I'm not sure how they're actually intended to function, but since these bags go inside of the inflated raft, they wouldn't need to be fully inflated unless you were counting on them to act as some sort of redundant floatation measure (boats are required in some areas to have 3 chambers). I presume – perhaps incorrectly – that 95% of the time you would just add your stuff and close the drybags without topping up the air.

In situations where you do top up the drybags by mouth, I imagine most of the bag would be inflated just by virtue of filling it with stuff, so you're probably only dealing with a breath or two of moist air (pure speculation). That's not much and I suspect only on long damp trips would it be a potential problem. In this situation, you could store your sleeping bag inside of another dry bag inside the alpacka drybag. For example, store your sleeping bag in a 1oz silnylon roll top dry bag, toss that in the Alpacka dry bag along with the rest of your gear and then top up the air as needed.

I am just getting into packrafting, so I am not speaking from experience:

• Depending on the trip you need more or less redundancy with your waterproof strategy
• The weight of stuff-sacks and dry bags adds up quick
• I love gear and spend plenty of money on it, but cuben stuff sacks start to offend me at some point.
• As far as I can tell, Sil-Nylon is not really waterproof but can be good for moisture management http://jwbasecamp.com/Articles/DryGear/index.html

I have made a dry bag pack liner perfectly sized for my 50L pack that weights 4.5 oz from the materials available at DIYpackraft.com The roll top is made from a stiffener on one side and a 3/4″ webbing strip on the other. Looks good so far. I plan on building some more for inside the cargo fly. It seems to me the optimal setup when it comes to weight would be:

• oven liner or nyloflume bags for redundancy with critical items
• The pack liner/drybag means you can
  • A) strap the backpack to the front of the boat
  • B) place your empty backpack INSIDE of it to keep it dry
• And/or two long skinny dry bags that fit side by side in your backpack that can be taken out and put inside the boat
• I am curious about a inflation bag that also serves as a drybag

I’ll be playing around with making some stuff this Winter