I'm sure you have seen this done before, but this is my version. This was made from mostly spare parts and material I already had in my shop. However I did price out the copper fittings and you should be able to build this for less than $8 - $10 max.
Tubing cutter - ideal to have but you can use a hacksaw, just be sure to deburr the edges.
Vise grip pliers - (preferrably two or even more - to hold things while you solder them.
Fine steel Wool - shine off the oxidized copper for better solder adhesion.
Acid paste - for the joints to help the solder adhere.
Aviation or Tin Snips
File - to clean up sharp edges
#10 or #12 AWG copper wire for designs.
Propane tank with tourch tip & control valve.
Drill motor , drill and screwdriver
1. As with any propane tank use, be sure to be aware that heated objects - especially copper, conduct heat rather quickly. Be sure to have a designated area for warm parts - away from possible ignition sources.
2. Use gloves to prevent burns and hold parts by the use of a vise grips. They also help to hold parts exactly as you positioned them while the solder cools.
3. Acid fumes - the smoke arising from the heating can easily irritate your respiratory system. do this in a well ventilated area.
Come up with your piping arrangement and test fit all of the parts to be sure they fit together easily and the dimensions are correct for your arrangement. When cutting tubing, i highly reccomend using a tubing cutter as they make very clean cuts compared to a hacksaw. They are realatively inexpensive and are definitely worth it. A hacksaw will work but it will leave burrs that have to be filed off and they tend to cut crooked.
Clean all the ends that will fit together with fine steel wool. The slightest bit of oxidation will make for a poor joint. Shiny is what you want.
Wipe the fitted areas of the fittings or tubing with acid paste to help clean the bonding area. Fit one or even to pieces together then heat the joint area with the propane flame. When you see the acid flux start to smoke it is close to the melting temp of the solder.
Touch the solder right at the seam. When it melts, capillary action should pull the molten solder into the crevice. A little goes a long way. becareful of falling solder splatter.
Continue building the assembly until you are complete with the tubing. Now it is time to fabricate the holder.
I cut the back support from a sheet of spare flashing material. it was quite thick but I still wanted some improved stiffness to it so I decided to solder a design to the back. That is when I stumbled on the method for attaching it to the piping. I used #10 copper wire stripped from some 3 conductor romex.
I wound the wire around a piece of tubing leaving plenty of extra on the front side and plenty out the rear. This was to allow plenty of freedom to make up the design then cut it shorter. I then cut out a few leaves and flowers to help pin the wire down to the back support.
I bent the back support by using my bench vise and a steel block anvil i have. It would be much easier if I had a sheet metal pliers (wide style) but the vise worked ok.
Use a vise grip pliers and clamp the wire into the shape you want with the leaves in the grip as well. Then solder away! Here is where more than one vice works great because as you heat further down the wire, the previous joint can let go as the entire assembly gets warm enough to flow the solder.
I also stamped in a few designs on the flowers and leaves by use of a number stamp. Look close and you will see I used the number 1 to stamp in lines.
This was a small challenge but with a little patience it can turn out really nice. I used brass to mix up the medium a bit. If you are not sure how to layout a cone on sheet metal, there are a number of sites that can caluculate this for you and give you the exact layout for the shape of horn (read as truncated cone) you want. I ended up layout mine in paper first, then adjusted it then tried it on the pipe assembly. The paper cone made a huge sound difference!
So I then made a cone of the sheet brass. Bending it can be tricky but I was fortunate enough to have sheet metal hammers to form it. Or you can hit the sheet over the hard edge of a vise or steel block. Same difference!
Keep adjusting the cone shape until it fits in the reciever pipe well. Use gloves and vise grips here so you do not cut yourself!
Once in the shape you want, the same soldering rules apply, steel wool it then acid flux it. Heat to temp then add in the solder. More is only required to perform a good seal all around. On my cone note that the inside seam is a bit off center line. It was the outside seam I aligned up. Looking back at this, I wish the inside seam was the one I aligned as it is more easiy seen! UGH! Too laxy to change it now!
Lastly I wire brushed the entire assembly to shine it up, then I sprayed it with a light coat of poly ureathane to keep it from oxidizing. I then mounted it to a board and added in a small pen holder to mack it just that much more functional!