Dry Bag -> Pump Sack + Camp Shower

Just got into a camp after a day of hiking and not looking forward to blowing up your air mat? Anyone using thermarest Xlite or Xtherm will know what I am talking about. In this instructable I will show how to convert a dry bag (regular stuff sack will work) into a pump sack for your air mattress . As a bonus we will also add a little modification to make it a camp shower. The shower part will only work if starting with dry bag.

• Dry bag - 10-20L would work best
  
• Empty plastic bottle
• Plastic bottle cap (2)
• Exacto knife/small saw
• Rubber "O" ring, the one for a faucet
• Glue or epoxy
• Scissors (optional)
• Sanding paper

The first thing we are going to do is to prep materials, bottleneck, cap, and dry bag.

1. Cut off bottleneck off a plastic bottle. Cutting close to rim is best. Some bottles are thicker at the area, so be careful if using a knife. I find heating up an edge of a knife to melt rather than cut works well. Also a thin saw as I am using in the video.

2. Once the piece is off, clean sharp edges with sand paper

1. Mark a hole with approximate diameter of inflatable mat valve. I use O ring as it is similar to valve diameter

2. Cut a hole using a knife. Remove sharp edges

3. Mix epoxy (skip if using ready glue)

4. Apply mixture inside a cap and glue O ring inside

1. Chose a spot near the bottom of the bag, about 1-2 inches or 2.5-5cm. It would make easier to hold bag steady during pumping

2. Put the bottleneck inside the bag , sticking out through the fabric as shown

3. Screw the cap on, giving at least 2 full twist. Do not over tighten

4. Mark hole and make a cut. After removing the cap make hole bigger. Larger the flow the more air will go through.

5. Reinstall cap on the outside. You are ready to pump your mat

Unroll mat and insert the pump valve nozzle into cap , but do not push too far in , just enough to seal the hole.

Open the bag ...blah blah blah you know what to do PUMP IT UP!

Using larger bag works well. You can see me using my backpack liner bag. NOt waterproof and leaks some air but works well. I only need 4 pumps to fill the mat

Use a new cap and make about 1mm holes in it. You can use a small nail for example by heating over your stove. Whatever you use protect your hand or use pliers. I find that five 1mm holes are enough for decent water flow. My yellow bag with 5L of water lasts 2mins. Experiment for your own need using different caps and diameter holes

Close the bag with solid cap (without any holes) and fill with water (in this case about 5L). Close the bag leaving partially filled, this allows to lay it flat and change the solid cap to one with holes.

Enjoy your shower