So I tried my hand at soldering it this time -- in the seam. First I checked the internet for suggestions and found this at the The Carburetor Shop.
If the float should need repair, it is important to understand how the float was originally produced. Virtually all brass float pontoons (the floating part) are composed of two pieces (a few are more) of brass soldered together. The pieces differ in the seam area, as one piece has a male seam and the other a female seam. One float piece will also have a small hole for temperature equilization. This hole will be covered by a small drop of solder, and will be as far from the seam as possible. The manufacturer would solder the two pieces together, allow the float to cool completely, AND THEN close the equilization hole. Soldering MUST be done using a soldering 'iron'. Repair should not be attempted using either a torch, or a soldering gun. If you plan on disregarding this advice, read the next paragraph first! The following procedure works for us (no, we will not repair your float unless we restore the entire carburetor): First, if liquid is present inside the float, find the hole, and remove the liquid by placing the hole down inside the hot water. The pressure will force the liquid from the float. If the float has much liquid, it may be necessary to remove the float from the hot water, allow the float to cool, and repeat the hot water dip. Once the liquid has been removed, and the leak has been marked, open the equilization hole by removing the solder. Solder the leak closed using as little solder as possible. A small piece of tape over the equilization hole will allow the hot water test to be preformed. If there are no leaks, remove the tape, and ALLOW THE FLOAT TO COOL COMPLETELY before closing the equilization hole. A final test, and you have 'saved' a valuable float.
So after taking the carb apart, and removing the float, I tried the hot water test and found it leaked along the seam for almost 2 inches with a couple of tiny holes. I followed with several hot water soaks until it felt like no more gas was inside then tried soldering with my pencil and eventually it appeared to quit bubbling. I am filling the carb bowl with gasoline and then sticking the carb together with a couple of studs and leave it to sit for a few days to see if it does again leak.
