This soap mold is basically the same as in the previous post, but with a few minor changes. For one thing, you'll use downspout sections that are 3 or 4 feet long instead of the smaller 1-foot sections.
Drill a hole in the end cap that will accommodate a plumbing nipple. You'll want to have a rubber washer glued in place and glue the nipple into place over that, as well. The nipple needs to fit your bicycle tire pump nozzle or your air compressor nozzle. Glue the end cap onto the end of the downspout section. Use this for your soap mold, making sure to cork the hole you've created. When the soap is cool, you'll use a bicycle pump or air compressor to shoot the soap out of the mold.
Remove the cork, and put the nozzle of the pump or compressor over the hole. Blast it with air and shoot the soap out. Once, it's at least part way out, you can pull it the rest of the way, if it doesn't shoot all the way out. Generally, using an electric air compressor will achieve a full shoot-out.
Do I have all the measurements and specs? No. This is a tool that you'll need to create using what you already have available to you, which could vary slightly from home to home.
