Moderated Discussion Areas
  ContinuousWave: The Whaler GAM or General Area
  Effect of Gasoline-Alcohol Fuels on Fiberglass Resin Fuel Tanks

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Effect of Gasoline-Alcohol Fuels on Fiberglass Resin Fuel Tanks
ratherwhalering posted 07-24-2006 03:37 PM ET (US)   Profile for ratherwhalering   Send Email to ratherwhalering  
I have done some research regarding the resins used in fiberglass tanks made by Plate Plastics of Miami.
For a quality report of ethanol and fiberglass fuel tanks, see:

The following is quoted with permission from that article:

This is what we believe is happening:

Polyester resins, gel coats and fillers commonly incorporate phthalates. In even the best resins and layups a small proportions of these phthalates remain unreacted. There are several water-soluble molecules that are found in these materials and they play a central role in blister formation and delamination. Phthalates are only sparingly soluble in water, however many are readily dissolved by ethanol.

Whereas gasoline free from ethanol never picks up phthalates, when ethanol was introduced the very small ethanol molecules diffused into the fiberglass, filler and gel coat materials where they dissolved unreacted phthalates. Having been dissolved by smaller molecules, and almost certainly accelerated by osmotic pressure, some portion diffused back to the surface and was dispersed in the gasoline. Based on our GCMS results to date there are some other, presently unidentified, large molecules that were also leached out by the ethanol and similarly transferred into the gasoline.

This internal solution and diffusion back to the surface is the process of leaching.

Since they are in solution, the phthalates and the other heavy dissolved molecules are able to pass through the fuel line filters. When the gasoline with ethanol evaporates in the carburetor the heavy molecules do not evaporate but come out of solution and are carried along in the air-fuel mix as an aerosol. When the droplets impinge on throttle plates and on the walls of the induction system they can collect as reported by Chuck Fort at BoatU.S. We do not presently know if after impingement the films are immobile or if they are able to migrate through the induction system towards the intake valves. Some of the molecules that impinge on the hot valve stems and under the crowns decompose to leave carbon powder and ash. Others, such as the phthalates that in general have exceptional high temperature stability, remain intact or undergo only partial decomposition and then act as the binder that holds together the carbon particles and ash as the observed, black sludge.

Frederick G. Hochgraf,
Senior Scientist
NH Materials Laboratory

Beginning this month, Pate has upgraded their resin from Poly-lite 32773-00 to Hetron-FR998 INF-25.

For information on Poly-lite 32773-00, see: BrandID=13
The manufacturer, Reichhold, does not recommend this resin for fuel tank fabrication. Although Poly-lite 32773-00 has a low styrene content, it not been certified by Underwriter's Labratories as resistant to fuel and fuel additives, such as ethanol.

For information on Hetron FR998, see:
The manufacturer, Ashland, reports that Hetron FR998 is:

Highly flame retardant epoxy vinyl ester resin formulated with less than 35% styrene. Excellent thermal properties and superior corrosion resistance to hydrocarbon solvents and oxidizing media.

pglein posted 07-24-2006 04:11 PM ET (US)     Profile for pglein  Send Email to pglein     
Hetron is what we used in the production of dual-laminate tanks and piping systems for refineries and chemical plants. We lined the systems with plastics (hence the term dual-laminate) for superior resistance to corrosion.

Perhaps going to a dual-laminate design would eliminate the problem once and for all (although also drastically increase the cost).

pglein posted 07-24-2006 04:19 PM ET (US)     Profile for pglein  Send Email to pglein     
One of the things that people need to remember is that these things have what is called a "service life". You can't buy something like a fuel tank and expect it to last forever.
BOB KEMMLER JR posted 07-24-2006 05:00 PM ET (US)     Profile for BOB KEMMLER JR    
pglein-For the price of one of these tanks,they better at least outlast me
sr posted 07-25-2006 12:52 AM ET (US)     Profile for sr  Send Email to sr     
Now this rather disturbes me. I believe I will be calling Pate again, tomorrow. During the previous thread my contact with them indicated absolutely no problem with the resins leaching from my 1991 fuel tank. Obviously they are concerned enough to us a different, or better resin.
ratherwhalering posted 07-25-2006 01:10 PM ET (US)     Profile for ratherwhalering  Send Email to ratherwhalering     
According to Pate, their tanks are suceptible to degredation from Ethanol. Pate explains that this may result in "fish scale" like residue in the tank, not liquified black sludge as reported above.

Chuck Fort, the editor of Seaworthy magazine, has only 4 reports of Pate tank failures. Of these four reports, only one reported a 'black sludge' residue in the tank. The remaining three reports were related to structural failure.

Pate believes that the liquified black sludge is a result of poor quality fiberglass resin and interior tank gel coating.

Pate states that Poly-lite 32773-00 was a high quality, low styrene content resin. There is no interior lining, other than a laminate resin.

Pate recommends inspecting the tank and aluminum screen on the pick-up tube regularly, in addition to installation of a quality in-line fuel filter.

ratherwhalering posted 08-04-2006 02:15 PM ET (US)     Profile for ratherwhalering  Send Email to ratherwhalering     
A final note. Pate has changed resin manufacturers primarily in response to market concerns. Pate has been in business for over 35 years, and changed formulas in order to assure its customers that they are doing everything possible to provide a product that addresses problems posed by these new fuels. It is an indication of their commitment to their customers and the boating community.

The folks at Pate have been forthcoming with all the information I requested, and have spoken with me, at length, regarding the manufacturing process. Pate does not have a customer service department. When you call, you either speak to Barbara Pate, Joe Pate, or someone on the manufacturing floor. I suspect that some of the terse replies were from the plant floor, and not Joe or Barbara.

Hoop posted 08-05-2006 11:27 AM ET (US)     Profile for Hoop  Send Email to Hoop     

Thanks so much for the diligent work to bring us up to date on the Pate fuel tank situation. Helpful comment regarding who answers the phone!

Best regards,

Currently ... Friday Harbor, WA

TightPenny posted 08-11-2006 02:58 PM ET (US)     Profile for TightPenny  Send Email to TightPenny     
I had the occasion to call them this morning. They told me essentially the same thing, that they had just changed resins based on the concerns being raised by customers. This is not to mention all of the horror stories that we all read everywhere.

I really had called to see if they could recommend an ethanol resistant gasket for the filler cap. Mine is disolving as we speak. The tank was new last year (the Tempo warped its way into big time water leaks).

They told me that there really isn't an ethanol resistant gasket that they know of. The did tell me that they would be sending me a couple of gaskets at no charge to replace the one I have.

They seem to be really nice people, anxious to help a customer.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.