A new tank

I think you'll find that no reputable welders are interested in welding on a 50 year old gas tank. I had the same idea, just wash it out real good, hook up a couple of fans and let it air out for a couple of days... how tough can it be, right? Well, I talked to three well respected welders and each said it was an awful idea, and they wouldn't do it. My tank didn't have any holes all the way through, and wasn't leaking, but it had deep pits, which as I picked at them with an ice pick grew larger and deeper. I considered trying JB Weld epoxy, that's marketed as appropriate for patching automobile gas tanks. But the nightmare of developing a leak and having the bilge fill with fumes interfered with my sleep. Your call, but a new tank and hoses will give you years of peace of mind.

Designed it exactly how I wanted it, including a threaded "stick hole" to check gas levels if the gauge stops working. We typically only run short distances, and I like to have fresh gas, so moved from a 75 gallon tank to a 40, cost $400 delivered to my door. I actually picked up range, because the new 4 stroke gets close to three times the mpg of the old two stroke.

Call luthers welding in Bristol ri for a new gas tank
401-253-5550

Another good option is Eric Kent, KentFab, in Pembroke, MA, at 339-244-4531.
Eric did the tanks for my 23' plus a bunch of other work. Very high quality and
very good to work with.

I ended up buying a 17 gal poly tank. should be here next week. hoping it fits. im loosing 10 gal of capacity . won't be able to go to the backside of the vineyard anymore.

Couple of options on range for you

Portable fuel tank you hook up
https://www.amazon.com/Scepter-08669...nVl&th=1&psc=1

Or gas cans.
https://www.homedepot.com/p/Garage-B...B351/307464272

We take gas cans out all the time to have spare fuel onboard.