well, I drained the tank after work today and found my pinhole. I hope to clean the s*** out of the tank and then use a 1 inch square of fiberglass saturated with por15. I will brush some sealer on, put the fiberglass cloth on it, then brush and saturate again on top of the patch

That doesn’t look too bad. I think you will be successful on this next attempt.

No, it's not as bad as I thought is was gonna be. I'm guessing that that hole is at the very bottom of the V where the two pieces of sheet metal come together right above the weld. It's still baffling to me how the POR15 didn't reach that hole and weep out like it did on the others, but like I said before, I depending how tight that V is, there's almost nothing that can get down there and clean it out. And like someone else said, if it's varnished fuel, the cleaner/degreaser and tank etch won't touch it either.

So, while I was waiting on my fresh can of tank liner to arrive, I went ahead and started cleaning out the tank again, and you guys were right. My tank was nowhere near ready to put my first can on sealer in! Like half the liner material came out from high pressure air and water from the hose nozzle. I got everything I could out and figured I'm screwed, but still decided to solder up my leaks (I had 3 pinholes) The other larger ones seem to have sealed up from the POR15 seeping through them then curing. One opened back up again from the heat I used to solder. I rinsed and rinsed, put spray nine in, hot water, rinsed again, cleaned the outside around the holes with a wire brush on a dremel tool. Then just took my small butane torch, flux, and solder and went to work. Took about half an hour, but I got them to hold water. It's not pretty, but they do not leak. I should have done this to start

Well done, soldering, or even better brazzing , in my opinion is the right way.
Welding-in a new sheet of metal would be the optimum

Sorry, if my opinion is differerent to other members, but i dont think. a 2-component sealer repair, like POR, is a long-lasting solution
For me, its a ticking time-bomb.
Better to go the more inconvienient way, like, you did.

you could almost arc a piece of wire across that w/auto battery then grind off...provided no fuel vapor left.

Got it going this afternoon. Installed and airbox I got on ebay, boot has been soaking in wintergreen oil and alcohol since Friday, and managed to get that thing over the airhorn of the Chinese carb that was on the bike. I got a OE Mikuni that I am slowly building, but the slide and everything that's on the cable won't swap over from PRC carb to Japanese carb. But it's all good. It took 50 years to get this F'd up. A few months of fiddling with it isn't a big deal

tank leak fixed, bike got back in the dirt for the first time in God knows how long. Still waiting on reproduction air boot so I can get the Mikuni back on. the float or float valve keeps sticking and gas pours out the overflow until I beat it back into submission