As far failures of Caswell, it’s due to prep work or lack there of. It must be clean, real clean. On glass tanks I use acetone, sloshed then dumped, let dry. Coating , It must be completely covered I slosh it all around and let it set on its top for about an hour prior to curing, then back on it’s bottom. I use an adjustable plumbers rubber plug for the fillerneck and rubber corks for petcocks. On glass tanks I’ve never had a failure and always drain the fuel.
If a tank is painted I recommend wrapping it celifain taping it real good especially at the filler neck, sometime I us think foil on top of that. Of course you go Commando
if your real careful.
I have 66 T bolt re chromed lined with Por 15, no failure after ten years, I leave fuel in it sometimes, condensation not a problem because entire tank is coated. On steel tanks you should use a mild acid etch, neutralized with baking soda, rinsed and dried.
The fuel now days starts to crap out after 30 days. I use StayBil in all my gas unless it’s race gas
It sounds Like KFB is a good product.
The only coating failure I had is with Cream…. I think I used Naphtha to clean it all ll out. I still have the tank today.
If by chance a Caswell failure happens it can be cleaned and recoated in that area, it’s only epoxy resin.
Finally, I use racing gas in my Hornets, I have 10.5 to one estimated compression. I do mix it with the 91 crapola provide to us CA.