Again, Thanks for the complements and comments. I'm always interested in answering any questions someone may have. Sorry about not updating the progress for a couple of weeks. Things have been progressing, sometimes I've forgotten to take pictures as I go along, some of it hasn't been picture worthy, and some I've just been tied up traveling to Minnesota and back. .... Anyway.....
The next step was putting the fuel tanks back in, however I knew there was at least some work needed before tossing them back in the boat. Among other indicators, when I first brought the boat home (almost three years ago now), and got the engines going, I noticed that the valving for the fuel tanks had both engines drawing off the port tank and nothing from the starboard tank. I definitely thought that a bit curious, maybe it meant nothing, maybe it meant something. Well, when I remove the cockpit sole this past winter and pulled the tanks I found that the pipe fitting for the vent fitting in the starboard tank was just rattling around in the top of the tank, and the tank had about 5 - 7 gallons of just ugly looking green water in it. That explained the fuel valving as it was. Apparently the solder joint for the vent fitting had let go decades ago, they were getting water in the tank, and so the tank was simply "condemned" and the boat ran only on the port tank for decades.
Now that I had the tanks out I could correct that.
These tanks are Monel. Monel pretty much makes Stainless Steel look cheap and disposable. It also has the advantage that it does not have to be welded, it "soft solders" very well. This made the tank easily repairable. Monel used to be a fairly common material for tanks on custom and semi-custom boats from the 1930?s well into the 1970?s.
Here is the Monel stamp on one of the tanks.
So saying, I know they needed some attention, but were completely repairable (even though they are 560 years old).
Once I felt I had made the repair to the vent fitting on that one tank, and touched up a spot that looked like it may have done a bit of weeping years ago it was time to pressure test them.
Here is the rivet that may have done some weeping.
It also helps to have a number of REALLY big old electric soldering irons at home (I mean with like 1 pound copper tips on them).
Here is the tank set up for pressure testing.
I sealed up all the openings, attached a 5 PSI pressure gauge, and connected the airline from the compressor with a regulator.
Add a bit of air.
......... and then go over everything with soapy water looking for bubbles. I actually did find a couple of small spots where the solder had basically worn through where the hold down blocks had rubbed. Touched those up and ..... no bubbles, no leaks.
The one tank that had been condemned decades ago was good to go. I gave the inside a good washing and sloshing with Dawn dish detergent and lots of water (again, it had not seen any gasoline in decades). The inside came out nice and clean looking.
I also found and retrieved 5 broken of fuel dip sticks from one tank, and two from the other (another indicator that one tank saw a lot more use than the other).
Now I have two 60 year old 60 gallon fuel tanks that have been pressure tested and are as good as new.