ABS-epoxy compatability?

[riverboathank]

I'm considering using Beckson ABS deck plates (screw in lid, neoprene seal) as inspection covers for composite diesel fuel tanks. Without having to mock up a sample, can I seat the ABS housing in epoxy? Any problems with this type of deck plate for this diesel tank use? Appreciate your input.
Regards, Hank

[Bob Cleek]

If The Chemist is around, I'm sure he can explain why epoxy bonds well to some plastics and not at all to others, but that's how it is. I can't say for sure that it will stick to ABS. Perhaps somebody else knows. I'd bet that Beckson would surely tell you their ports are NOT suitable for fuel tanks, given liability issues, if nothing else.

However, for what it is worth, I wouldn't advise using plastic of any kind (nor really even epoxy coating, although I know it's done) for fuel or other petrochemical applications. There is a decided tendency for diesel and gasoline to break down plastics sooner or later. While (metal) tanks certified for combustables are more expensive, they are really a worthwhile investment in safety. Moreover, you don't want to finish your boat and find that nobody will insure it because the fuel system doesn't meet the fire safety standards.

[John Bell]

Based on my experience trying to repair ABS whitewater canoes, I'd say that you aren't going to find much that will bond to ABS.

An elastomeric substance with greater adhesive properties would be better for bedding plastic ports and such as these.

Finally, I would not use anything that was not specifically rated for fuel contact in the fuel system of my boat. It may work out just fine. But if it doesn't, the consequences of failure are just too severe to justify any cost savings you might realize.

[ 01-09-2004, 03:55 PM: Message edited by: John Bell ]

[imported_Daniel]

There is a two part epoxy called Wet Bond that I have used a few times in the past to join ABS to cast & other metals. It is a white colour when mixed. This stuff really works well, I even patched a hole in the bottom of a dirty old grease interceptor with the stuff, worked great. It's not cheap though, about $16 for a double syringe.
Wet Bond (http://www.wet-bond.com/)