Topic: Fiberglass Tanks?

[Boziboard]

I was wondering what people think of fiberglass gas tanks and what their experiences have been?  I am converting a 1974 cb750 into a cafe bike and the tank is pretty banged up and those Dunstall replicas look pretty sexy, but I have heard stories of newer formulation gasoline eating away at the tanks resin or getting into the gas itself and resetting in the carbs.  Any feedback would be appreciated.

[pwright]

From my epoxy experience (however none of the stuff I've done has been on tanks...) there are a number of resins that will stand up to fuel. Vinyl Ester resins in particular will work well, but are pretty nasty to work with. People who build composite airplanes commonly have tanks made out of fiberglass and epoxy resins, and I'd be hard pressed to believe the aviation industry would accept anything substandard. Some of these planes have been flying since the late 70s when composites started to change the homebuilt airplane industry- and since the tanks are built into the wings, they haven't been modified since being built. You might want to ask the people who build the cafe tanks what they use, and then do some research on your own as to compatibility.

A good epoxy and fiberglass site I've spent a lot of time on is:

 http://www.fibreglast.com 

There should be some good info there...

Best of luck,
-Pat-

[oldbiker]

Have a look in the Tech Library at  http://sohc4.us/?q=node/53  There is a good article on custom built gas tanks.

[bryanj]

The later Dunstall body kits were just a thin glass cover that went over the standard tank as the UK outlawed fiberglass tanks on bikes built after a certain year (cant remember what year) due to tanks splitting in an accident. Its not a very well know or rigorously enforced rule but Dunstall was a major supplier and so changed his parts.

[kyre]

just remember that fiberglass tanks don't dent when dropped, they crack which "could be" a problem.

[Geeto67]

if you are worried about your tank you could have a radiator shop put a redliner in it. Redliner is a plastic like coating that is poured in and when it hardens it makes a nearly indestructable liner (the only way to get it out is to burn it out). We used to use it on really rusty steel tanks, may work for fiberglass, and may even give you some piece of mind in a laydown.

[theunrulychef]

Doh!!!!  Why couldn't I have seen that article BEFORE I started the mold for my tank.  Now I've got the mold plug (positive model of the tank) skimmed with so much bondo trying to get it smooth that I wouldn't want to keep all that weight in there under the fiberglass.  I guess I can either continue down my "positive plug - 2 part negative mold - 2 piece tank glassed together" route, which should give me a smoother, perfectly shaped tank right out of the mold.  Or I can spend 2 hours reshaping some foam, glass the whole thing, & spend another day or two finishing the outside of the tank.  Man, what a sucker!

Thanks SOHC forums... for showing me what a clueless jackass I can be!

[seaweb11]

I would be interested in hearing others ideas on this subject.
Would a tank "1975 tracy" that has already worked for 30 years now have issue with new fuel? One would think it's had some new fuel in it already?

Will I need to treat the inside?

[puppytrax]

Have a look in the Tech Library at  http://sohc4.us/?q=node/53  There is a good article on custom built gas tanks.

...??...What article??..   

[wardmoto]

pwright is...correct.  While there is a fiberglass/resin combo that works, next to no one does it because it is toxic as hell.  One person in the states does and I have a CR 750 glass tank from him and a CR450 seat pan.  The quality was awesome and just to be on the safe side, I sealed it with tank liner from Bill Hirsch Automotive (there is no better liner!) If there is a legitimate interest let me know, I am not sure how busy he wants to be.  Also, I have it painted and mounted on my recently all but completed 350F cafe, but despite everyone being nice and telling me how to resize pictures, I haven't done it yet!  I can e-mail any pics you want.

[OldSchool_IsCool]

OK, here is a whacked idea, glad I stole this ID to ask it! 

What about a fiberglass shell to slip on and off over a existing tank in good shape?  Just for colour and slight contour changes like ribs or a spoiler or a frigg'n cup holder, I don't know!  But, could it be done?

Too whacked?

[paxtonpony]

Here's a full dunstall kit if you're looking for one:

http://cgi.ebay.com/ebaymotors/Vintage-Dunstall-Cafe-Motorcycle-Fairing-H2-AHRMA_W0QQitemZ280076869339QQihZ018QQcategoryZ35583QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

BTW, I'm not the seller, just happened upon the thing and thought it was cool.

[seaweb11]

The one above is one I am selling and it is a cover skin.

The NEW Tracy bike I am getting has a glass tank included with the body.