Well i'm not saying it won't work, i'm saying the company itself recommends using a different product to seal fiberglass tanks...so if that's the case I won't run the risk. Supposedly from what my rep said they are coming out with a fiberglass tank sealing product soon, and it will be along the lines of a two part epoxy sealer like the Redcote and Caswell ones.
The main issue is again that their tank liner is meant to adhere to a surface that is etched and has a certain PH level and even a slight level of oxidation improves adhesion in that case. Something that can't occur in a fiberglass surface.
Just like you can prime on top of bare metal with regular 2k primer when you are painting a car...and it will work...but long term adhesion is a problem, that's why they make self etching primers. There are reasons certain things are specifically recommended. Especially when it comes to paint/sealers/body stuff.
I hope your liner never fails, and i hope your tank doesn't get ruined...and who knows it probably won't. But that's a situation where it's a risk I am not willing to take. So if someone now wants to seal a fiberglass tank they just got, of course i'm going to recommend NOT using POR15 tank liner. If anyone already has and it's working fine, they are lucky people and there is nothing wrong with that. But this is a case where the company says NOT to use it!
Well said. And I agree completely.
Any engineer that has seen his product design through to completion/production has learned that a test case of one is inconclusive. Just because a prototype seems to function, does not prove that you can make 10, 100, 100,000 or a million that will work exactly the same way.
A good mechanic can make almost any machine function as desired by applying his skill.
A good engineer can make a million machines function as desired without requiring such a good mechanic's skill.
POR-15 manufacturer doesn't recommend it's use on Fiberglass, and there are likely good reasons for this. One possibility, is that there are many formulations generically called "fiberglass", that have widely varying materials used for the resin that holds the glass together. As noted, chemical bonding has many variables to consider.
During a casual search, I found that Red-Kote won't stick to fiberglass. FYI
http://seattlecycle.com/red-kotetankliner.aspxSo far, the Caswell and KBS products seem to be the lowest risk choices for fiberglass liners. Now, I just need to figure a way to protect the unique paint job already applied to the outside of it.