Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Hornet/Spitfire Fiberglass Tanks

I know someone who makes modern fiberglass tanks and seat pans for flat track bikes. He recently started making Bultaco fiberglass, including tanks.

He uses modern materials and all tanks are Caswell lined. He won’t ship a tank without lining it. I am actually waiting on a tank now that is being made to my specification for petcock ports to accommodate the FI system on the bike.

Before I ask Kevin if he is interested in looking at making modern tanks for the Hornet/Spitfire/68 FS, is there any actual interest in a modern tank that can be used in the real world on these bikes? Realize, petcocks and cap may be modern instead of original, but his billet caps are nice looking. If he could find a source for the Monza filler neck, original caps are possible. Correct petcock bungs may also be possible.

I have a 66 tank with indents and a 68 tank with studs I would be willing to loan him for molds.

Tab classics in the UK make an excellent alloy hornet style tank, but it has the early style (victor GP type) cap. I did ask them if they would do a Monza? 68’ style flip cap… got no response.

Rich,
When you say modern components, is he going to use a ethanol resistant fiberglass resin? My understanding is that the problem with ethanol and fiberglass is that the resins that were used were not resistant to ethanol and that there are new resins that are. If others have different info feel free to correct me. I coated my tank with Caswell's, but when they increased the amount of ethanol in gas, I didn't feel a coating was a permanent solution and bought a decent, albeit not perfect, Indian replica. If your guys tanks are simply going to be newer tanks that are just as susceptible to damage without a coating, I don't see a lot of folks ponying up.

Ed from NJ

You could try British American Transfer, they have Monza caps
https://www.batinc.net/aston

Randy Baxter has steel ones in stock. If it’s for a spitfire it doesn’t have the indents for the graphic. I purchased on for my spitfire.

I got that wrong it isn’t the Monza that I was after

but this type (see page 4 )Ceandes catalogue

I didn't know they ever published a catalog!

Interesting stuff. Thanks for putting it on this site.

Ironicly I was actually after the updated catalogue, the cap on P4 is still available with the lollipop shaped button, smooth rectangle and ribbed rectangle. However most suppliers only ever stock the latter… annoyingly.

Kevin uses modern materials in his tanks. The materials are supposed to be ethanol resistant. But, he has found the suppliers don’t always maintain their formulations batch to batch. And, he and both believe ethanol s only part of it, modern fuel is a witch’s brew of chemicals.

That is a long way of saying he made a business decision to only sell tanks that are lined by him.

The Monza cap was on the Victor aluminum tanks and the '64/'65 Sptifire Hornet tanks. The newer style Ceandress caps were on the '66 to '68 2-gallon fiberglass tanks, ie Hornet, Wasp, Spitfire, Firebird Scrambler. The reproduction Ceandress caps available have spline lines in the rectangle release button. Original Ceandress had the lollipop release button, then the smooth rectangle button which is the most common. Some lollipop button caps are found on '66 glass tanks.

The factory used polyester or vinyl ester resin in "boat style" typed glass tank construction. Those resins cannot withstand modern fuels with all of the various chemical in it. Epoxy resins are now mostly utilized in glass construction with modern construction techniques, some of which are "wet lay-up", "molded spray", "vacuum bagging", "pre-preg" and other techniques. Epoxy resin has the best chance to withstand the chemicals in modern fuels. Caswells tank sealer is an epoxy resin.

I have had excellent success with original glass tank restoration when sealed with Caswells.

Glass tanks are not for everyone. They are not an install and forget part. They require a higher level of care, inspection, maintenance, and usage than a steel or aluminum tank.

I applaud Rich's friend Kevin for being in the glass tank construction business. It is challenging to do.

The issue with a liner in a fiberglass tank for me, is that while 10% coverage in a steel tank is fine as long as it fills the pinholes, anything less than 100% coverage is a failure with a fiberglass tank. Before the Indian steel copies were available, I coated my tank with Caswells. I sluiced out the tank with whatever Caswells recommended (some sort of solvent), and then let the tank sit for two weeks with the petcock holes and cap open. Poured in the Caswells, swirled it around and then opened the petcock plug to pour out the excess (again in accordance with the directions). First out was an ounce or two of the solvent! Realizing that this had gone bad, I went to a fiberglass specialist who was a retired NASA composites engineer. The first thing he told me was that using double the amount of Caswells as lots of folks suggest is a bad way to go. He said the resin in the fiberglass and the resin in the Caswells have different coefficients of expansion and a thick coating will eventually separate and be difficult to remove. He said you should use the thinnest layer you can, with complete coverage. He then cut the bottom of my tank off at the seam with a utility knife. Took him about 5 minutes, I was surprised at how easily it came apart. He then brushed the Caswells on. Once it had set he re-fiberglassed the bottom on and used a tube and a hose through the gas cap to lay a bead of Caswells along the seams. It worked well, but when they increased the amount of ethanol in gas, I figured it wasn't a permanent solution, bought a metal copy and put the factory tank on the shelf.
Since your guy is building new tanks, it may make sense for him to line them the same way instead of waiting until they are done and sloshing the liner in.

Ed from NJ

I use 1/2 of the Caswell sealer kit in the 2-gallon glass tanks. Even with that quantity, there is drainage of excess resin.

Several years ago, I used Caswells in a brand new British made fiberglass tank.
In about 6 months, the gel coat started to get blisters and wrinkles in it.
Obviously something went wrong, but what.... who knows ?
The only thing I deviated from was using extra Caswells, figuring all it would do was make an extra heavy coating. Perhaps
THAT was my downfall.

As discussed above for splitting an old tank, I would think for a new tank that you could seal prior to joining top and bottom. Last fibreglass tank I made, 20 years ago mind you, had a final inner layer of 'fuel resistant' resin. Then top and bottom were bonded. Dont remember the specifics, but it works well if all done in the process. There might be an argument for lining after joining top and bottom, havent kept up with this as I havent needed to.

The topic of lining FG tanks, which we used for racing, was active even 20 years ago prior to the widespread introduction of EToH into fuels.

As Rich says above. This does depend on the supplier giving you what you think you are getting. I'd think an inner layer of epoxy resin would be good, but I'm sure Rich's guy has it all sorted.

For a petcock bung I used a correctly threaded adapter screwed in to a small piece of aluminium sheet with some holes drilled in it to help it bond into the resin . That's pretty do-able.

Cheers
Ray

The only time I've seen Caswell tank sealer fail in the way you describe was from incorrect or insufficient tank interior preparation. A sealer failure could also occur from incorrect ratio mixing of resin and hardener. Unlike polyester and vinyl ester resin, epoxy requires a certain ratio mixture each and every time. More hardener is not better, nor will it cause the epoxy to "fire off" sooner.

Also, it's possible that epoxy will exotherm too fast when in a confined space and/or it is too thick. Too much heat is generated within the epoxy mix when subjected to too much heat (confined area, too thick). The hotter it gets, the more heat it generates upon itself and the faster it "fires off" resulting in an inferior finished product. When this happens the resin may have excessive air bubbles and/or air pockets within itself. Structural integrity is diminished if it "fires off" or cures too fast.

Another potential failure can occur when going beyond it transition temperature to failure. Epoxy will begin soften and could fail at excessive temperatures above 150 degrees. As an example, a factory built Lancair aircraft wing constructed of epoxy composite panels and materials painted red, sitting on the tarmac in full sun had a surface temperature of 140 degrees. It is plausible that a motorcycle fuel tank painted red, or a dark color and/or with metallic paint could reach and go beyond the resin transition temperature and fail.

Buy a new STEEL tank and be done with it.

What a mess.........Alex Sohn just posted a video on FB of his Triumph 250 with a hornet tank painted by Don Roe 10+ years ago. I REALLY liked the look.......enough so that I contacted Tab Classics ( damn you Allan )

I can't help but wonder what Rich's friend would charge for a new fiberglass tank.

Gordon.........who's always looking for a better tank for my unit singles.

I've had no problems with a vinyl ester tank I made when they first put chemicals in fuel that ate polyester. I don't use ethanol fuel, but didn't with the polyester tank either. The vinyl ester has no coating. I have no experience with ethanol in it, it's only 94 non ethanol fuel can be 95 and 98 and mpg is so much better it works out cheaper in cars.

Ben's bike uses a steel std tank so is much easier. And steel may not be quite as light as alloy, but when they are both full it's not much different.

I’ve often wondered how you go about making a glass tank, I’ve always wanted to make an A50 Daytona tank since no one is making them. When the only thing you have is pictures, you kinda want to make sure you have it right first hand.

There seems to be a lot of topic usurping here. Anybody care to comment on the original question.

I think price is always a factor. I’ve made a few enquiries on different subjects over the years. Most places will give you a ball park figure to see if you bite or not. If you do and agree to the minimum order, then they will price accordingly

Lota thread drift but........it keeps it near the top of the "Active Threads" so if you're looking for exposure, that's a good thing.

It's been almost a week.......

I'd like to know what a ball park figure is for a "one off" new fiberglass hornet tank.

Rich might be getting over run with PM's on it.

Gordon

I haven’t seen what I would call a lot of “desire” for new tanks. But lots of thread drift.

The hardware (cap, petcock bungs) is going to affect price. 1/4” pipe to use modern flat track style petcocks with an off the shelf screw in cap is going to keep it below $400. 3/8” BSP bungs and correct Monza cap, I am going to guess $425+.

I have a new tank for the race bike on the way. He told me 2+ weeks since I wanted specific bung location, it shipped in less than a week. Ethanol resistant materials and Caswell lined, $360.

I will post some pics of the tank after I get it.

You can do it two ways
Both require a mock up in styrofoam
Then either use to mock up to make a pairs of moulds for a two part tank & join the two parts together
or
put the glass over the mock up tank then pour petrol into it when finished which dissolves styrofaom in a few minutes
First method has a smooth outer with gel coat but a rough inner
Latter method makes a smooth inner surface with a rough outer that has to be sanded filled & top coated .
Proponants of either system will argue till the end of time as to which is better .

Just drifting over to Allen's question. The A50 race tank. Photo's from all angles you can get. Cut a ply profile and sit it on the top tube where it would go do other profiles and make like the frame of a boat. Maybe tape it all then with something to build on use body filler to finish. You could just use body filler or other lighter easier to shape filler on a smaller tank and build up. Cut the outside profiles as a guide. There is a type of F/glass filler that is very light to bulk up. Use a big rasp hacker thing, use body filler as a final thing and make it absolutely perfect, saves work. Put wax and mold release on it and make a fibre glass mold from it. The top and sides just go over usually. Unless the shape has protrusions or roll overs. So usually the mold can be a simple tub, or you can split it down the middle and tape it together and pull it off the sides if its complex. Which makes a 2 piece tub.

To make the bottom tape cardboard on the frame to fit with clearance, smooth plastic tape it all. Add release. Take a mold. When you have two parts trim to fit and test then glass the bottom in, chopped strand is fine but use vinyl ester not polyester as the first is chemical resistant. You can glass in ally blocks with holes threaded and glass in the filler probably before you fit the floor and it will be neat.

Make the first layer of the mold gel coat then add mat and resin. I cannot remember If I gel coated the outside of my tank, I may have just used Vinyl ester resin. But two pack paint is less effected by fuel spills. It also goes on like glass, but you cannot breath it. Better not to breath resin vapors either. Resin saturated chop strand doesn't need to be 6 inches thick. The chop strand gives it strength it needs to be saturated.