[BILL WILLIAMSON]

Originally Posted by MikeK

If Bert's reports this problem as altitude related, there may be some link to the manufacturing technique.

It is impossible to solder together a float without having any heat transfer to the air inside. If the air inside reaches 300F at the time the solder flows and seals the float, cooling to 70F will drop the internal pressure about 5.5 psi. If it was indeed manufactured at a high altitude like Denver (630 Torr) then sent down to sea level (760 Torr) the pressure differential would increase another 2.5 psi, to a total of 8 psi, enough to crush a paper thin brass float.

FWIW, applying Charles/Boyle's gas laws, the internal pressure change in a float between winter storage at 0F and a hot underhood of 150F is about 3.6 psi

The answer to this would be to look at the manufacturing process, probably sealing a final hole on a cold rather than overall-heated float.

This all makes sense, Mike, When I've repaired leaky floats, I submerge them in warm water, look for bubbles, solder them up, with the smallest soldering iron that will suffice. NEVER use even a TINY TORCH! If wirebrushed nicely, they solder well with rosin core solder. THEN punch a small hole to drain any water. After it's back to room temp, I solder the hole QUICKLY with a very SMALL soldering IRON. I've successfully repaired MANY floats on old S.U. carbs on Volvos & Jaguars. Bill W.