Caswell Curiosity

I too used POR15 in my Bonnie tank about 5 years ago and it has been good. The appearance is indistinguishable from when first applied. I have only used premium fuel so don't know how it would stand up to prolonged Ethanol blend use.

I am still working on this. The testimonials here are hardly conclusive but it would seem obvious that steel tanks are a lot easier to seal.

I personally don't agree with the idea of using a sealer that will result in a thick coat with a single application. All of the eggs in one basket so to speak. I prefer the idea of multiple coats and am working on this idea in my research. However, I spent some time talking to Matt at CNW about their use of the product. Their approach is well thought out and adresses some of my concerns over how this product might be missused.

I am also researching Gold Standard and Red Kote products. Both are single coat applications. Gold Standard says it must be sanded between coats, which of course is impossible. Red-Kote says it can be used for multiple coats without prep between because it contains MEK which basically softens the previous coat, eliminating prep work between.

The people at West System (epoxy manufacturers) have good results with Red-Kote, however the manufacturers of Red-Kote say not to use it in a fiberglass tank, as they pretty much promise it will come off the sides of the tank in big sheets. It might be a good choice for steel. Red-Kote is vinyl based.

Gold Standard is urethane based. According to the Red-Kote manufacturer the problem with urethane based products is that they shrink with age. Which is a big problem on the inside of a tank. I have not had the opportunity as yet to discuss this with the Gold Standard people, but will.

I am hoping in the coming weeks (months) to do some testing of various products. I will report back with any results worth notice. If I were planning on sealing a tank with the products available right now, one of my criteria for choosing would be based upon whether or not I could get the stuff back out using readily available solvents, as it would not surprise me to see some advances in this chemistry.

As for fiberglass tanks, the more I mess with this the more I wonder if building a mold off the old tank and making a new one out of a different type of resin (vinylester maybe?) might be the approach. Of course now I need to research whether or not vinylester resin will accept a decent paint job!

Russ

I would never seal a metal tank. Clean all the rust out (there are multiple ways to do this) and you're good to go.

Fiberglass? The only way I can think that would be surefire is to cut the bottom, clean and coat the insides with a modern gas-resistant resin. Oh, and not put gas in it. :mrgreen:

I talked to a friend today who restores old cars. He told me about an epoxy spray process for metal tanks (presumably it would also work on fiberglass) that he has used on several rusty car fuel tanks. He was working and I didn't want to take up a lot of his time, but I am definitely going to pick his brain further on this.

Steel tanks are relatively easy to prep and I think that if you follow directions any of the commercial coatings are going to work. I have Bill Hirsch's white sealer in my Roadster tank and it's been great for 7 years.

Fiberglass is another story. Caswell's is as good as any, and from reports in the forums it seems to be the most recommended. But I've painted a number of '72 Nortons, sealed with a variety of products including Caswells and Kreem, and they ALL failed after about 2 years. It breaks my heart to see a paint job that I was very proud of bubbling from underneath.

Modern fiberglass technology (petrol station tanks for instance) is not the same as our 40 year old bike tanks. If you use fuel with ethanol be prepared for paint damage. Experiment if you like, but that's been my experience.