Fiberglass Tank Frustration

[rick1]

Help!

I have a fiberglass Bultaco 199A fuel tank that is leaking along the bottom edge seems. The tank was sealed at one point in its life with a "Kreem" type product. What is the best way to proceed in resealing the tank:

a. Pour a new sealer over the existing one?

b. Try and remove/disolve the old sealer?

c. Apply resin to the drip edge seam and hope for the best?

I poured and flushed the interior several times with Laquer Thinner, although this did a wonderful job of cleaning the tank it did not remove the sealent material. I have considered flushing with Acetone, however, I am concerned that this would eat in to the fiberglass resin. I have also considered other solvents such as MEK (methylketone) but worry that this will have a similar affect as Acetone.

Any experiences or suggestions

[bob abell]

Hugh's has tanks

Mine has the plastic tank from new, not fibreglass.

Bob

[vintagecota]

Believe it or not, the easiest way to fix it for good is to cut the bottom out of it with a zip disc or dremel tool and clean all the kreme stuff out of it with sandpaper, then coat the inside with a nice thick coat of fiberglass resin or epoxy resin, then glass it back together with several layers of cloth strips over the taper-sanded seam. You can then sand it smooth if you wish, but since it's on the bottom, that's optional.

[monty-python]

I used to have a fibreglass tank on my old sherpa. I tried all of the above methods, without success.

the problem is that the fibreglass resin is NOT fuel resistant.

I eventually bought a plastic tank. No more problems.

I know it doesn't help your predicament, but i wouldn't hold out much hope of this repair job having a happy ending!!

[totalshell]

ive always used the white tank sealant from the shop in leeds ( whose name unfortiunately escapes me) YOU POUR THE STUFF IN SWIRL IT AROUND IT TAKES ABOUT 3 DAYS TO GO 'OFF' TO APOINT WHERE YOU CAN USE IT I'VE USED IT ON ALLOY AND STEEL TANKS WITH SPLIT SEAMS AND PIN PRICK RUST HOLES AND never EXPERIENCED ANY PROBLEMS AFTER WARD THE BENIFIT OF THE WHITE LINING IS THAT YOU CAN CLEARLY SEE HOW MUCH FUEL YOU HAV EIN THE TANK..

[trickymicky]

Thats probally Wylde's in Leeds. I think they do their own brand.If the lining is genuine Petseal, the manufacturers sell a solvent for removing the stuff as well.

[dirtmudnroost]

I have 2 MAR tanks that were in a bad way, fortunately the fibreglass had not gotten soft cause if it does your hooped cause then your only choice is to split the tank and do some lay up work, in my case I was recommended to use a product from Caswells Plating by the Composites Engineer where I work that is also a vintage bike enthusiast, I got it from the distributor in Canada but you will likely have to go here http://www.caswelleurope.co.uk/gastank.htm. The job was done 2 years ago and there have been no leaks what so ever and has stood up very well. On the one tank the inner surface resin layer was in very bad shape so I did 2 layers of the Caswells Fuel Tank sealer and is extremely easy to work with and sets up hard within the hour providing it is not done in a cold area. I would highly recommend you give it a try before shelling out major coin for a new tank.

Cheers

Glen

[scotty]

Bultaco uk, sell great plastic repro tanks in red or blue, this is the way i'd go!

[rick1]

Thanks for the help. As I wanted to keep this cheap I decided to do the following. I got all the old sealer out with repeated Acetone rinses. I am going to do 2 or 3 pours of resin in to the tank and swish it around until each one sets up before adding another pour. I plan to then line the tank with Caswell which is available here in the US from Hughes Bultaco. For the two pucker marks (gashes) on the exterior I am going to trim up some fiberglass strands into very short lengths (2 - 4 mm) and mix them with the resin to fill in. Then sand smooth after it sets. If I can get it done for under a $100 dollars I'll be happy, beats a new one for $300 and I can put the difference towards some new rear shocks.

[paulthistle]

Rick1,

I'm going to assume the "white sealer" was Kreme. My question is did the acetone soften it up, or dissolve or what? I have a TY tank that looks horrible but all the metal looks good! The Kreme inside looks like the Alps! What method did you use that seemed to work the best?

Thanks

Paul

[twinshockdude]

sealing products work ok in metal tanks BUT NOT FIBREGLASS ones,the problem is that the

fibreglass becomes impregnated with 2 stroke oil over a long period of time and bugger all will

stick to it,dont waste your time and money!!

this pearl of wisdom was hard and expensive to learn.

[rick1]

Paul and Twinshock Dude,

I used Acetone to clean out the tank. I poured a pint in and swished it around for 5 minutes or so. I would then let it sit for a couple of hours and swished it real good. Then I emptied (it disolves the Kreem so it pours right out) the tank. I repeated this 4 times cosuming an entire gallon of Acetone. Each time I repeated the process I laid the the tank on a different side when I let it sit for a couple of hours. I used a rubber stopper in place of the gas cap and petcock. The Acetone will also release whatever oil / gas residue in in the fiberglass. Just to be sure I had some Lacquere thinner laying around so I did a final rinse with this. Make sure your in a well ventilated area when you use this stuff, I did it outside. Also, where safety glasses or googles and gloves. You don't want this stuff in your eyes or repeated exposure to your skin. Also, Acetone can eat / soften through the resin if left too long so I wouldn't leave it for more than 24 hours.

There is a product called Caswell designed for sticking to fiberglass. I have spoken to a couple of people who have used this in older well used tanks and they have had very good results with it. Hughs Bultaco in particular has used it and have good results.