Leaking Gas Tank 1904 Griffon

[cycarmark]

The copper gas tank on my 1904 Griffon motorcycle has a leak in the divider between the fuel tank and the space that holds the battery and trembler coil. It looks like someone has tried to solder the joint, but was unsuccessful. My question is there a way to clean the joint in place and melt the solder that is there into the joint, maybe using a particular flux to clean/prep the joint.

[PaulCDF]

CCMark

I am not familiar with the Giffon set up. Like most things prep is half the battle. Need to really clean failed area.

Could you post a picture?

I was working on my 1941 Indian 741 tank (steel) using:

70/30 Bar Solder
Ruby Red Fluid flux
200 watt soldering iron

AMCA magazine archives:

Winter Issue, 1993 Vol. 32, #4
Tech Tips pages 24-27
Antique Motorcycle Gas Tank Repair,
Part I by George L. Yarocki

Spring Issue ,1994 Vol.33, #1,
Tech Tips pages 22-25,
Antique Motorcycle Gas Tank Repair,
Part II by George L. Yarocki

For professional help:
Alex Trepanier
Harry’s Radiator shop since 1919. Los Angeles CA 626-592-2212

Another option (and I will be using on my 'repaired' 741 tank)

Caswell epoxy gas tank liner available at Caswell Coatings
consider giving it a look.

All I got for right now. Hopefully others will chime in.

[cycarmark]

Hi Paul, thanks for the reply. Here are a couple of pictures of the area in question. The leak is in the area circled in black.

[PaulCDF]

Thanks for the picture Mark

All looks pretty easy to access.
In those AMCA articles the mention is made of also using; Brass wire cloth 40x40x.010 dia.
I have used that to repair holes and likely you could solder in a new "corner" here.
Practice on some scrape first and see if you can clean out the failed solder.

PS after my first post I had to look your bike up. That is a REALLY COOL Machine.

[cycarmark]

Here it is, it's running now, but only on a float chamber worth of fuel until I get the tank fixed.

I appreciate the help and the sources for information and will let you know how it all goes.

[T. Cotten]

It doesn't look that frightening at all, Mark!

(When oil is involved, its scary.)

My approach would be to start with just a couple of psi and soapy water to determine exactly where we need a fix. Then with a triangular scraper, to try to retrieve, or carve, a 'fillet', or chamfered edges of the copper plates that are mated with solder.
(The ferrous terneplate that I am more familiar with was all pre-tinned with a solder compound, and fresh metal was actually detrimental!)

Nonetheless, scrubbing with carb cleaner, some 'Ruby Fluid', a solder of whatever the experts prefer, and a righteous iron should be satisfying.

When the tank seems to be drawing off too much heat from the seam, I found that adding a hair dryer on high was ideal, but it took three hands.

...Cotten

[cycarmark]

Success! I ended up scraping/wire brushing/dremeling out a good bit of the old solder to expose the joint area. Using lots of ruby flux and my unknown wattage soldering iron I was able to fill the area. I ended up using a torch very carefully to smooth out the joint (I think my iron was a little too low wattage). Of course this fixed the leak I knew about, then soap bubble testing exposed other leaks on the back end of the tank. Someone had replaced the back panel of the tank at some point and did a beautiful job soldering it in, and then they smoothed the solder so much that it went through and exposed the seam. I had to re-solder about 5 inches of seam in the back but I finally got all the leaks sealed.

I suspect the reason for the leak in the battery/coil area was there is a mounting bracket just behind the joint that failed and if the bracket was over tightened it would pull down on the bottom of the tank and separate the bottom from the vertical partition.

The previous picture of the bike was before I made the float chamber top, intake manifold, and replaced the old leather belt with a v belt, attached is a picture of the bike now.

Thanks for the help, advice, opinions, etc.!