This is my homebrew version of a cool tool called the Icebox. It's a three sided box on the end of a pole used the way a compass is used for drawing a circle, only in 3D so it makes a dome. It's sold for backpacking, so it packs down small and light. I didn't want to buy a real one just to try it, so I made my own. My version doesn't fold up for travel.

Supplies

I made it from scrap wood, a roll-up plastic sled, some Great Stuff foam, an aluminum pole from IKEA's bargain room, and some miscellaneous screws, bolts and bits of copper pipe, duck tape, etc...

Step 1: Plant the Center and the Box

Plant the center and stomp it firmly into place.
Slide in the connecting pole and plant the box. Push it down till it stops then make sure it's level.
Fill it with snow. Pack the snow. Add more snow. Pack it into a ramp that goes about halfway up the box.
Open the box by lifting the handle of the closer bar and sliding it to the open position (see pix).
Move the whole box to the left until the closer bar is above the edge of the first block.
Close the box! Fill with snow and pack to make the ramp come to the top of the box.

Step 2: Fill. Pack. Open. Move Box. Close. Repeat...

After you've built the ramp, you will be making full blocks, filling the box all the way. Pack it in. Add snow. Pack. Add as necessary till the box is nice and full of packed snow. Then open the box, move it to the left carefully so as not to disturb the previous block. Close the box. Fill etc...

Step 3: Keep Going

After 3 or 4 times around the circle, you'll need to cut a small door. This is so helpers can keep bringing you snow. I use snow knives to cut the door. They're shaped like a big chef knife but not sharp at all. Perfect for cutting snow. Make the door small for now. Just big enough to push a sled full of snow through. We'll enlarge it later.

Step 4: Take a Break. Enjoy Progress.

Step 5: Near the Top, Take Off the Outer Panel of the Box.

You don't need it anymore since the top is approaching horizontal.

Step 6: At the Very End, Take Off the Side Panel

It starts to get in the way. All you'll have left is the back panel. The last bit of snow gets applied from the outside of the igloo. With the back panel in place, throw a couple of shovels full up there. Pat it down with the back of the shovel. You won't be able to reach with your hands.

Step 7: Have a Little Party.

Step 8: Optional. Add Eyes If You Want To

I used this tin can hole saw to bore the eyes.

Step 9: After the Roof Caves In...

It can still be pretty fun.

Step 10: Building the Tool...

Since I built this several years ago, I don't have many photos of that process, but here are some pix of the tool with notes so you can understand what I did.