Tinsmith's in frame gas tank for cantilever Schwinn.

With the bends made, Dan carefully checked to see that the fit to the side piece was just right. The bend points needed to be carefully marked and the bends clean. Getting one wrong would be tough to redo without starting over on the long top piece. Dan is pleased with the fit and sandwiches the side piece between two of the wooden forms which are held in place with clamps. The inside form gives a backing while soldering the top and side piece together. The outside form further stiffens things up and protects the tin from being marred by the clamp. Next up is soldering it together.
(cont.)

As with so many things in fabrication and in painting, preparation is what takes most of the time and makes all the difference in how well things turn out.
There are different kinds of solder. When I made stained glass windows I used a 60/40 solder which was 60% lead and 40% tin. Dan is using 50/50, half tin and half lead and for certain things he has used a solder composed entirely of tin which leaves a shiny surface. Lead tends to dull when left to oxidize. If clear coated while it is still newly soldered or freshened up with fine steel wool, it should retain its shine. For my V8 gas tanks I have used silver solder and either a propane or butane pencil torch for the soldering. Please note that a flux (which is an acid and allows the solder to flow into the metal being soldered) must be used. Flux appropriate for silver solder will not work with lead/tin solder and vice verse, so you must use the appropriate flux designed for the solder choice. Silver solder is quite expensive compared to lead/tin, so keep that in mind when making your choice. I can see that Dan's approach works well and from now on it is also what I intend to use, at least with tin.
Dan's flux is a liquid (there are also paste fluxes) and he has poured a small amount into a plastic container cap to dip a small paint brush into. He applies the flux to the area to be soldered, in this case the inside of the flange and also a quarter inch or so along the top piece.
Dan is using a hundred watt soldering iron which can accept different sized tips. For copper work a higher wattage iron will likely be requirted which will be discussed at that time.
He has on hand a section of sponge soaked in water and also a block of sal ammoniac. He could explain it better than me, but the sponge is useful for two things. He can fine tune the temperature of the tip by cooling it with the sponge and he can also clean the tip, wiping it against the sponge. When it is dirty the tip does not want to accept the solder, which it needs to do to be "loaded" with solder in the same way that a paintbrush would be loaded with paint. If my understanding is correct, the sal ammonica is also an acid and acts like a flux for the soldering iron. Preparing and loading the iron with solder is called "tinning" the iron. I also used to use fine steel wool to clean the tip. The sal ammoniac makes nasty fumes which are toxic, so avoid breathing it in when cleaning the tip and dragging the hot tip over the block. Ventilation is always a good idea when soldering with lead based solder. It, too, is toxic, especially to our nervous systems. Not a big deal for one gas tank, but for eight hours of soldering it can become a health issue. Just a word to the wise.
So, in short, Dan applies a flux to the area to be soldered, tins the iron and is starting at the point where the long piece of tin wraps around to the bottom. For this side Dan is running a continual bead as much as possible. It has been six years since he has been doing this work and while enjoying being "back in the saddle again" he says that he feels rusty and is not happy with the steadiness of the soldering line. But keep in mind that Dan is meticulous. If you or I did it we'd be patting ourselves on the back for a job well done.
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On behalf of Tinsmith, thank you for the positive comments. For my small part in this enterprise I'm glad for the opportunity to give back to forum members who have helped me so much in the past year and a half and for being able to give back to Dan for his kindness and generosity.
The tin work is something new to me and is a pleasant surprise. As mentioned earlier, my original quest was for a copper tank. Dan's suggestion to make a prototype out of tin was I thought to save some money over the more expensive copper. But now I'm seeing the tin as something to consider on it's own merit. I had no idea it would look so good!
It will be interesting to make the same tank out of both metals and will be a learning experience discovering ways in which they are similar and also different.
I am also pleased to have made new and good friends in Dan and his wife Jackie who feeds the boys when we come in from the shop. I as much look forward to our conversations and stories as for the shop time. And one of these fine days the weather will turn enough spring like for us to go bike riding... finally someone to go bike riding with, a first for each of us. Woohoo!

Where did we leave off last?... ah yes, Dan was joining the first side to the long top piece. In the next to last photo of this post he is tacking the pieces together at intervals to hold it tight, else the spring of the metal wants it to have a gap. Once tacked together he then goes back to run a continual bead across that run. In the final picture he has wiped the tip of the soldering iron against the sponge and is now dragging it across the block of sal amoniac, recharging the iron with flux so that it will again accept the solder. On the longer runs you can see how Dan holds the solder so that it continually recharges the iron making it possible to run a continual bead on the tank. Pretty cool.
(cont.)

The tank is taking final shape with the second side being joined to the top section. You can see how Dan has tacked it with solder at intervals as one would do in spot welding with steel. Same principle here. It allows him to have both hands free for his soldering, one to feed the solder to the iron and the other to guide the iron controlling the bead. Keep in mind that there is still an open section in the bottom of the tank, but most of the tank is together.
Time to try a test fit. Dan has already said he is afraid that we didn't allow enough clearance and his fear was justified. The tank is too big. Bummer. But it was meant to be a prototype to teach us how the tank wants to be made, what will work and what won't. We have learned a lot already which will leave us poised for an even better tank #2.
This is part of the process in making things yourself... starts and stops and wrong turns along the way. Keep this in mind when you ask someone to make you a tank or other part for your bike, especially one of a kind. A lot of thought and time goes into a project like this one, not to mention skill and experience. Sure this is just a gas tank for a bicycle with a motor on it, but it is also the culmination of a long tradition in making things of tin, with many generations of artisans coming before Dan ever picked up a soldering iron. It has been said that we stand on the shoulders of those who came before us, the artisans of another age and also the pioneers of bicycling and motor bicycling. it is a fine tradition of backyard mechanics and skilled craftsmen that you and I and Dan are part of. It is something to take some pride in, I think.
More will follow. By the time I got home Dan had already cut out tank #2 allowing another eighth on an inch or so for clearance. #2 will fit perfectly and when it is finished the copper tank will be next. Our thread will follow the process to the end. See you next time in Tinsmith's shop.
SB

I had taken Dan's unfinished tank #1 home with me as a kind of souvenir and was pleased to discover that the tank fits with a squeeze into my 51 Schwinn. The opening is slightly different from the 53 in Dan's shop. The 51 was a balloon tire bike while the 53 was a middleweight, even though to my eye the frames look the same. Apparently they are not, but they are close enough that I believe tank #2 will fit either frame nicely. So we will go ahead with finishing up #1 as well. It still needs the final section to finish out the bottom and in that section will be the means of mounting the tank to the frame, on this one it will probably be acorn nuts soldered from the inside. Unless Dan thinks of something better before our next session. We also have to solder in the gas filler and the gas outlet. Later,
SB

And I'm enjoying sharing this with everyone as a kind of observer and reporter of what Dan is up to. You and I are learning together at the same time. I'm looking forward to next Saturday and know that we'll be much further along at day's end. And I'm guessing that both tanks #1 and #2 will be done with a better idea of how to go about making a tin version and a good start on knowing how to approach the copper tank. Can't wait to try that burring machine myself. Fasteddy & BBB, you guys were lucky to have been exposed to some tin work while school boys. Baird, I've used a big electric iron for stained glass work years ago, but have also been using a propane torch for the V8 tanks. I'm anxious to try using one of the old copper irons for soldering tin and copper. I'll take some pictures of some of Dan's old ones next Saturday.
By the way, after soldering on tank #1 last Saturday, Dan washed off the residual flux with a combination of baking soda and water. The baking soda neutralized the corrosive effect of the acidic flux which would lead to rust if allowed to stay there. So even if you're doing a V8 tank, clean the tin with baking soda and water when you're done or rust will follow eventually. Something I learned from the Tinsmith and thought I'd pass along...
SB