Tank Sealant

Hi Guys This is my first post. I have a 750 Roadster 1971 which I have owned from new. I am close to finishing rebuilding it and bringing it back to it's former glory. The fuel tank is the original fibreglass model (Fireflake Royal Blue) and has never seen fuel with ethanol added.
Has anyone used or have any info on a product called "Slosh" tank sealant. I just want to be sure I select the "right stuff" to use and know you guys have the knowledge to help me make the right choice.
Think this site is awesome by the way. Many thanks. Ceebee

Hi Ceebee
welcome to the forum. Do a search on: fiberglass tank, Tank Sealant, Ethanol gas and you will have a lot of info to read.
CNN

Make your tank a nice garage display piece & start looking for a clean steel tank to use. Maybe some day we will have a sealer that truely works but for now it seems your just buying time with them.

Or use avgas, unless you make long trips and can't get to an airport. Best is steel tank. Don't try it yourself. Get someone to cut out the bottom and seal it from the inside, but still no guarantee.

Dave
69S

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Where do you live? Can you buy ethanol free fuel there? If so, don't seal the tank! Enjoy the fact that you have a rare and desirable tank and don't screw it up. Then hunt down a metal tank, and keep that one in good shape for show and tell.

Russ

Hi- +1 on get s steel tank. I tried 3 different sealers on my original glas tank, and they worked for a brief time- then started shedding goo into the carbs. Couldn't keep the bike running, and eventually gas ate through the tank and oozed out the sides! I bought a good used no-rust steel tank, have been delighted with it. Go steel. Or pony up a lot of shekels and have a polished alloy tank made- those are beautiful!! Good luck- ejd

End of an era for composite tanks of all sorts it seem, so take a change like me and try Caswells or Herich type sealers in good layers, or sell the tank to me as useless and actually possibly dangerous d/t its dissolving products getting into engine valves rings to seize, so I can use to hold my asshes forever in some quaint biker bar.

Ceebee said:

Hi Guys This is my first post. I have a 750 Roadster 1971 which I have owned from new. I am close to finishing rebuilding it and bringing it back to it's former glory. The fuel tank is the original fibreglass model (Fireflake Royal Blue) and has never seen fuel with ethanol added.
Has anyone used or have any info on a product called "Slosh" tank sealant. I just want to be sure I select the "right stuff" to use and know you guys have the knowledge to help me make the right choice.
Think this site is awesome by the way. Many thanks. Ceebee

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If this is the single part product sold by someone in the UK its not likely to work, as chemical resistance of materials used to seal tanks is enhanced by "cross linking" of component parts of the sealer during cure. Solvent based single pack sealers without a catalyst component, cannot achieve the same levels of cross linking of a novalac epoxy for instance, which is material that is resistant to Efuels, but due to its brittle nature totally unsuitable for use as a tank sealer!

There are industrial sealing products which are fully resistant to Efuels, and remain flexible so wont crack and fall off like the epoxy based products, but these seem to cost a fair amount of money, and not sure application is likely to be a DIY type job?

Thanks to everyone for your help. Guess I will have to bite the bullet and get a steel tank. Have heard the new offerings from India / Pakistan can vary in quality with sealing issues and dimensional problems. Will have to investigate that one further. I wonder which company produced the earliest steel tanks that were fitted as standard on production machines?
Where I live in England it is difficult to get access to ethanol free fuel. Avgas is out as it is illegal to use it on road machines over here. I could use an additive like TetraBoost to add lead but that doesn't eliminate the ethanol. Pity you can't filter out or remove the ethanol from the fuel some how.
Anyhow, I will post a photo of my bike when it is finished. Thanks again

Have a look at the FBHVC web site, where you will find some info on Efuels. Supposedly super unleaded fuels didnt used to contain ethanol, but there is no accurate information on any of this, which is understandable when you take into account the fact that oil companies are selling fuel which in some cases is not fit for purpose!

CeeBee, you've most likely spent a ton of $$ to get your bike back into shape and are ready to ride. Yes, there have been way too many threads about tank sealants, but IMHO there's nothing wrong with spending less than $50.00 to get some Caswell and have your bike ready to go in a few days. Just my personal experience, I'm going on three years, approx. 8500 miles and my Caswelled Dunstall tank is still perfect....no effect on the carbs or other components either.

Send me a PM if you want to go the Caswell route...there's "sloshing" Caswell around in your tank and hoping for the best, and then there's the CORRECT way to do it. BTW, there are many on this Forum who have applied Caswell and have been happy with the long-term results.

Like it or not when it comes to very brittle thin film slosh coat applied epoxy resins applied to GRP tanks, you need to have luck on your side for these to offer anything more than a short term solution to problems with ethanol fuels!


However the durability of the epoxy sealers can be greatly increased by the addition of some sort of binder material, which makes them a lot less likely to crack, and far more suitable for use in GRP tanks. Kevlar pulp seems a good binder to use, but I would think milled glass fibres would also be ok.

Ideally resin with binder needs to be warmed up a little to lower the viscosity, and the tank to be sealed should be kept moving until the exotherm is well under way, and only then should the surplus resin be drained off. Doing it this way is a little more difficult to do, but will mean film thickness is greater, and this in conjunction with the binder will give a much better chance of a long lasting repair.

Though my tank is steel I have had a sealant in it for almost a decade and it is still in tact and not causing me problems in the carb or engine seizing. I did take the time to ensure it was prepped right from the start which I thing is KEY to a successful coating. I think a lot of people must hurry through some or all of the process and get a failed coating. If it were me I would definitely buy a steel tank, but until I could find one I would seal the current FG tank and use it, but that is just me.

Steel tanks are not likely to affected much by Efuels, and neither are novalac epoxy resins. The deposits that you get inside the fuel system when tank sealer inside a GRP tank has failed are generally dissolved polyester resins from the tank itself, rather than anything to do with the sealer.

CF, I am talking about the coating inside. If it were affected it would be running slime through the carbs and motor wouldn't it? I know the gas won't affect the steel tank, but the coating itself should be affected no less than than being in a FG tank, right?

Any properly cured novalac epoxy is unlikely to be affected by ethanol. Problems arise when the epoxy coating cracks, and ethanol attacks the polyester resin of the GRP tank to which the epoxy has been applied.

OK, I thought the actual sealant was breaking down into goo. I didn't catch the part about cracks and seepage into the FG underneath, thanks for the clarification.

Like it or not when it comes to very brittle thin film slosh coat applied epoxy resins applied to GRP tanks, you need to have luck on your side for these to offer anything more than a short term solution to problems with ethanol fuels!

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AH Ha or Ah So Grasshopper!, who said anything about a brittle thin film---
No Sir Ree Bob, Caswell-Novalac is as thick as cold honey and if tank kept rolling till it gets so tacky it barely sags, let alone flows, will deposit it self in about 1/8" clear layer, on each application, depending on how brave or long you store spiked gasoline inside.

Besides Ms Peel's 7000 miles IS tank, that was last filled in '05, then sat half filled for 3 yr is still intact, but now dried out for 3 yrs - so is my buddy Wes's tiny HyRyder fb tank has lasted fine since '06, with no choice but to fill with what ever on tap every 50-60 miles or he risks running out before next station around here.
Wes did his in over kill thick to save the Burnt Orange gel coat finish. He put in a pint and turned and turned till it sat up and never poured any excess out. Said it reduced his volume but has to carry a half gallon or more with him anyway, or risk running out again before next station or farmer beg fill up. I have crashed on both my and his tank, my IS tank crushed in by handle bars bent impact and Wes by my knee fracture protecting its finish but jamming the headsteady through one side of the tank tunnel to leak,
until --- wait for it --- we JBWelded to seal just fine again 2 yr and 2000 miles later. Both of us did not put gas inside till weeks of set up, while major other repairs being done. Is cure time and temp a clue?

Yet Comstock reports after excessive clean and application, could not get Caswell to work long for him and a few others about equivalent in skill, same sad reports. So who knows why it has worked for some while others wasted time/money to still loose tank and spoil engine insides. Apparently normal filters are no protection at all either.

Steel tanks rust so still need to think about protecting them too, so Trixie's steel tank Caswell'd a few years ago, before two hard crashes smashed each side in but bondo and new paint, twice, still no rust nor injury to the Novalac. Must be my good karma, depending on ones view point. Lost ~ a pint capacity d/t coating and indentions.