If you would like to watch a video of me fabricating this bottle opener you can find one on my youtube channel here:
This requires 6 small pieces of metal, which I cut from an off cut.
You will require:
1 - dremel (or generic rotary tool) with cut off wheel
2 - Welder
3 - drill
4 - paint.
Option - bench grinder (you can always use the dremel)
Step 1: Cut Up Your Flat Bar in to 6 Pieces
Measurements can be pretty rough and ready, the important thing is really to grab a bottle and check the scale against that.
I started with this piece of flat bar (3mm/20mm) mild steel which was perhaps 6 inches long.
2x wide sections, peryaps 30-35 mm for the base and the 'hood'
2x narrow 'column' sections, these attach from the base to the hood to hold it at an angle
1x narrow section to act as the 'lip' which the bottle cap fits over
1x square 20x20mm section to create a tab at the top for the top mounting hole.
Step 2: Check the Layout
I found I was able to arrange the pieces against each other. Use a bottle at this stage to get the distances right for the two columns and the angle of the hood.
Step 3: Grind the 'lip' Piece to Provide a Narrow Edge
You need a fairly small protruding piece of metal that will hook between the bottle and the cap. I just ground the end of a narrow cut of the steel. You can adjust this later with a dremel if necessary.
Step 4: Weld It All Together
Start by welding the 'lip' piece into the centre of your base piece, with the ground end prodtruding a few mm over the top side.
Use welders magnets to help hold the pieces at hte angles you setup in step 2.
It won't take much to weld the small pieces together. Try not to go too hot as these small pieces of metal won't be able to dissipate the heat and it's easy to really melt them.
Step 5: Drill Mounting Holes & Grind to Clean Up
Drill a small hole either side of your lip piece, and one through the tab at the top. Counter sink to give space for the screw heads to sit flush.
Then go at it with a grinder/dremel to clean up your welds (if necessary) and generally soften the edges.
Step 6: Spray It With Metal Paint
For this a simple cardboard box as a spray booth and suspect the opener with some thin thread. This allows you to spray it all around in one go.
The metal paint will want a couple of coats, but that will prevent it from rusting up. I went with classic black.
Step 7: Screw It to a Solid Surface - Go Get a Beer
Find somewhere handy to mount it, and screw it in place.
You might also consider something to catch the bottle caps.
You're done! - saving a random off cut from the scap pile, and turning it into something kind of useful.