Bertram31.com General Bulletin Board

Re: enough chicken little

Posted By: Charlie Haws
Date: Monday, 20 March 2006, at 10:51 a.m.

In Response To: Re: enough chicken little (Tony Meola)

My chicken little comment was aimed at the near hysteria over the ethanol dissolving the existing polyester tanks. It seems this happened after a tankful or two went throught the engine. The tank should be disintegrating right before your eyes for that much styrene alone to be causing the problem. Polyester is a styrene based polymer. Polyester resin is normally air-inhibited, which means it typically remains uncured (sticky or tacky) on the surface when exposed to air. To cure reliably, general-purpose polyester resin( with a wax additive) needs to be applied in at least 15 to 25 mil (.015" to .025") thickness. It is not very effective as an adhesive (partially because it will not cure thoroughly in thin films) and is only marginally effective as a repair resin for repairing well-cured polyester/fiberglass laminates. The ethanol needs uncured (sticky) styrene to dissolve and than maybe coat your valves and guides. If the tank did not get a proper cure it may be a problem. When many of these tanks were made Bertram did not really understand the chemistries involved. I do believe vinylester is still styrene based. Check me on this as I am an epoxy/polyester chemist. I think they have developed better formulations that more completely cross-link the styrene. Once it is cross-linked (cured) ethanol is not going to dissolve it. I guess you tank will dissolve at rate determined by the quality of the lay-up and cure. If you have time study the effects of temperture on cure do so. It's effects are major. Bottom line is some tanks are going to fail sooner as opposed to later and many have failed just with straight gas with no ethanol over the years. What are you going to replace your polyester tank with? Aluminum? Vinylester? Stainless Steel? High Density Polyethylene? how about Epoxy? Monel? I DON'T THINK WE KNOW RIGHT NOW. What I am sure of is; I don't want to take the word of a tank manufacture unless it is backed up by scientific proof and a written warranty. Not some thing you read off an internet forum.

Messages In This Thread

Another angle on ethanol
Peter -- Saturday, 18 March 2006, at 12:32 p.m.

Re: Another angle on ethanol
Harv -- Saturday, 18 March 2006, at 1:13 p.m.

Re: Another angle on ethanol
Tony Meola -- Saturday, 18 March 2006, at 7:15 p.m.

Re: enough chicken little
Charlie Haws -- Saturday, 18 March 2006, at 9:30 p.m.

Re: enough chicken little
Tony Meola -- Sunday, 19 March 2006, at 8:26 p.m.

Re: enough chicken little
Charlie Haws -- Monday, 20 March 2006, at 10:51 a.m.

Re: enough chicken little
Peter -- Monday, 20 March 2006, at 5:19 p.m.

Re: enough chicken little
Tony Meola -- Tuesday, 21 March 2006, at 10:00 p.m.

Re: Another angle on ethanol
Walter Kaprielian -- Saturday, 18 March 2006, at 6:20 p.m.

Re: Another angle on ethanol *LINK*
Peter -- Sunday, 19 March 2006, at 3:59 p.m.

Re: Another angle on ethanol
Charlie Haws -- Sunday, 19 March 2006, at 6:04 p.m.