Tank coating on new tanks

[454MRW]

I just talked with Dennis Jones about a brand new aftermarket fiberglass TY175 tank/seat combination that he coated with POR-15 clear that he had problems with.
The coating was gelling and soft, unlike the coating on the Penton tanks and was plugging up his fuel filter, and gumming up the carb slide. The tank was bought new recently and the inside appeared to be more smooth and looked more like it had an internal coating, possibly more like SMC fiberglass, as opposed to the original Polyester Fiberglass, which the Penton and older tanks and pre-1975 Corvettes used, which POR-15 works well with.

If you are considering coating a tank that is not the standard Polyester resin design, at this point I would not recommend the use POR-15 clear for that type of tank, but so far I have not heard any adverse effect on the Penton and similar older style fiberglass tanks, which the POR-15 Clear surface remains hard and scratch resistant.
I do strongly recommend coating tanks on a dry, non-humid day, as mosture tends to dry the coating faster and may cause tiny air bubbles, although they don't seem to be detrimental to the coating.

I will continue with updates as they are available. Thanks, Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR250 & OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R & CR150R

[TedG]

I have had experience with this and POR-15 has a high failure rate. But there is a product that works. And if you follow their directions to the letter it will last forever. Caswell has a very, very good tank sealing compound that I have in a bike that has the crappiest fiberglass around. It is Champion glass for a flat tracker. The tank leaked (30 years old) and I used the Caswell and followed their instructions to the letter. Even used the acetone and sheet rock screws to rough up the inside of the tank. Two years later with fuel that has sat for a couple of winter months the tanks coating is still hard and glossy. The stuff works, and they even have instructions on how to repair failed POR-15 and Kreem failures. Just thought I would share.
http://www.caswellplating.com/aids/epoxygas.htm
Here is the bike I used it on.

[454MRW]

Just to clarify the POR-15 I use is NOT the tank coating they offer, which is a much softer compound and prone to failure. It is the POR-15 Clear paint, which remains rock hard indefinitely. If anyone has had a problem with the POR-15 clear, please let us know, otherwise, the only problem I have heard about is the one with Dennis's new aftermarket TY175 tank. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR250 & OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R

[desmond197]

Caswell works well to seal a tank but you can not use fuel with ethanol. It will turn it orange and start to flake. I have an Alpina tank that is trashed due to this. Race gas with no ethanol or marine gas guys for bikes with fiberglass tanks.

[454MRW]

Over this past week I got a call from Dennis about the tank/seat combination that he purchased for his Yamaha TY175 and he told me that he had purchased another new unit for his bike. He reported that this additional new tank he bought also failed within less than 2 weeks after using pump gas in it with no coating, and it appeared to him that the problem is actually with the improper type or quality of resin that was used by the manufacturer and most likely not the application of POR-15 clear paint that he coated the first tank with. He spoke with the manufacturer and is returning the tanks. There is a great deal of difference between commercial grade and hobby grade resins, and the manufacture may have been trying to get by with the cheaper route, unfortunately. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR250 & OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R