copper fuel filter tutorial

It is no secret to those who know me that I love stuff made from copper and brass, but especially copper. I think of it as "poor man's gold" and when I can I like to incorporate it on a vintage build. Vintage and copper seem to go together, in my mind at least.

A few years ago I did some experimenting with an idea on making my own fuel filter out of copper. The result is pictured below with filter #1 installed on the Villiars engine sitting in an Atco mower frame which will power my hybrid delta trike. Although the filter was made a long time ago I never used it, having made it originally for what became the Indian Hiawatha tri-car.

What I'm going to show you today is how to make one that is twice the length of the original. It has room for a bigger one on the 3 speed Elgin velocipede which already has a copper headlight in the works and copper jewel tail lights in back. I'll do a similar tutorial on the jewel lights later in a different thread.

Pictured are the pieces you need to make the filter. I am using 1" copper water pipe fittings. There is a section of 1" pipe from which two pieces will be cut, a coupling to join two sections of pipe together and two end caps. Also pictured is a section of brass tubing from which I will cut two short sections which will connect to the fuel line. I searched this morning for some 1/4" soft copper tubing without luck and didn't want to make a 25 mile round trip to town for a few inches of tubing. In my search I ran across a non functional propane torch so decided to use it as a donor, removing the fittings and cutting two straight sections from the brass piece you see. I used a Dremel type of rotary tool with a cut off wheel to do this.
SB
(cont.)

By the way, in the third photo of the prior post the parts of the filter are shown both in pieces and assembled, other than the brass tubing for the fuel lines.

Both end caps were drilled for a 1/4" hole to receive the brass tubing pieces. One photo below shows the tubing in place in the end caps, but not yet soldered. It also shows the whole filter together. From the long straight section of 1" pipe two shortish pieces were cut to fit in each end of the coupling and the end caps are also in place. Another photo shows the end pieces ready to solder. Next shows the end caps with brass tubing soldered in place. There is an order to the soldering. Do these end caps first before there is any filtering medium inside the main body. Stainless steel wool (found it on ebay) is the actual filter to stop junk from getting into your carburetor. I forget where I read about stainless steel wool as a filtering medium, but it was in some high tech application where quality mattered. Mine is a low tech application and it matters to me.

So the main body of the filter is now stuffed with stainless steel wool and in the final photo flux is applied to the joints before fitting them home and soldering them in place.
SB
(cont.)

So the filter is all together now. I used a little grinding wheel on the rotary tool to clean up the solder goobers. When heated and molten the solder becomes a liquid and flows downward with gravity. On something round it is pretty hard to avoid this happening. So it gets cleaned up. It may look to your eye like the solder is not there in some places, but inside the unions is where it matters and the solder flowed there and with the help of the acid flux made a bond.

I checked for leaks with a section of clear line and poured in some rubbing alcohol to see if a leak appeared anywhere. Happily, no. I learned some years ago while making gas tanks that checking with water is not effective since water is "thicker" than gasoline or alcohol. I didn't want to use gasoline in case there was a leak and I might need to apply solder again. Alcohol evaporates pretty thoroughly, so I went that route. If I have been misinformed on this point, some smart person please correct me... thanks.
SB
(cont.)

And this is where I want to fit the copper fuel filter. It will eventually connect with a cylindrical copper fuel tank immediately behind it. I like it. Cool beans!

So that's it. Feel free to ask questions if there are any. It is pretty simple, really.
Fuel filter #1 is half the length of this one and does not use a coupling. Otherwise it is put together in the same way. I think that when I make the next filter I'll use copper foil over the joints so that the seal is on the outside and more visible to the naked eye to see that all is well with the soldering. No leaks without the need for testing. Thanks to Cannonball2 for reminding me about copper foil. I have rolls of the stuff from when I made stained glass windows for a living. Why didn't I think of that? Next time. Thanks for reading the thread.
SB