I have sort of stalled out on my CB750 project. I think that is is SO important to me that I am having a hard time doing the last little bits.... it is ironic because I have been trying to build this bike for about six years, and now that I have everything together I am struggling to assemble the engine and finish the last bits.
A few weeks ago (Saturday ,Sept 2nd) I got all inspired and decided to try something crazy -- to "hammer out" an idea that had been rattling around in my head for some time now. I have an old CB750 gas tank that has been sitting on the shelve for years. It is a bit rusty and dinged up, and it has a really horrible old rattle-can black paint job. It always was WAY too ugly to do anything with it, but not quite ugly enough to throw away.
I have been considering buying one of those flashy customized tanks which recently have made a serendipitous flurry upon the market. There have been some very nice “race-style,” all steel ones which have sold for $300 to $450. But I have this old tank sitting around.... Normally I would have just pulled the dings, used a little Bondo, re-lined the inside and it would be as good as new. But this time I decided to experiment with hammering some into a tank. I have never done this before, but I am the kind of guy who will try anything once.
That was a few weeks ago, and now I have a rough, but really slick starting place for a seriously cool petrol tank.
Here are some pictures. Like always, you can click for a larger/better view.
U-G-L-Y! This is one ugly old tank.
I got out a few different hammers and laid them out on my work bench
Then I mounted the tank on the bike and with a white paint pen I roughly marked where the knee cutouts should be and where the clip-on handle bars need some extra clearance.
Then I took my yellow multi-purpose hammer and just started whacking the devil out of my tank. After a while I started to have a nicely defined knee cut out shape on each side of the tank. It actually didn't look bad.
Then I got the idea of using my pneumatic chisel to help me hammer. I dug out my ever handy 16mm medium-deep socket (yeah I used it every day too...) and fit it on to the end of the chisel. It gave a nice round, yet flat hammering surface, and the process immediately became more defined and about twice as fast.
After about two hours of the loudest racket you have ever heard this is what I had.
Another shot.
One more. because these are kind of cruddy pictures, I think that it is difficult to see how cool this tank is starting to look. The lines are well defined and it has a very unique shape from the hammering. When these tanks are reshaped by cutting and welding the lines are very different, but because of my hammering technique the lines are unusually smooth and curved. It truly has the promise of being very cool and particularly nice!
At this point my neighbors started to complain about the incredible racket I was making and I had to stop. I think I have about one more hour of work before I am finished. Right now it is still all real rough, but it still is looking pretty good. I am imagining that after I finish hammering the tank I will strip the paint, coat/rust proof the inside, and then try to do something cool and different with it. I want to see if I can take silver solder and tin the recessed areas. That stuff can be real pretty when it is polished up, and if I am real careful I think I can pull of a nice glassy surface. I don't know – I've never tried that before, but if I can do it it will look very special.
So far I have about two or three hours invested into this project and no $$. I imagine that the old tank maybe was worth about $15, eBay value. I estimate another hour or two of hammering, and I have no idea how it will go from there.
Wish me luck, and I'll keep you posted as progress is made.
Peace and grease
-fang
