Caswell sealer failures? Please report

Anonymous Carbonfiber has been educating us on the details of diluted Caswell Novalac tanks sealer vs best industrial strength resins to save old school fiber tanks from new school ethanol fuel. I surveyed Brit Iron list last month to get 2 reports of Caswell failure, one 2 wks later another 2 yr later in Calif. Question is, were these failures of application or innate fault with Caswell sealer sold?

Over last decade have read a over a dozen surprise carb clog to engine seizure from un-coated tanks and about as many of finding flaked and dissolved POR15 and Kream. There was a rash of Caswell coating done about 7-8 yr ago but I'm not hearing of rash of Caswell failures. So confused if no one is testing with ethanol or Caswell applied well is up to the task. Me and my buddy Wes had committed to Caswell before we heard of its possible worthlessness. So we are part of the on going testing, sorta of.

Any bad Caswell reports among forum?

It appears that coating a glass tank will buy you a couple of years and that's about it. I coated my 750's Fireflake Royal Blue tank with Caswell about four years ago and the coating is still hard, but the surface of the tank is looking kind of lumpy now. I think the fuel has gotten past the coating somehow and is attacking the fiberglass. I don't know if I had voids in my coating or if, as has been suggested here, that the coating cracked from vibration.

I have also heard that there are some fuel formulations out there that will turn even Caswell epoxy to goo. I haven't encountered any myself, but one of our club members has. The bad gas was in PA if I remember correctly. All it took was one tankful...

Debby

Ugh, thanx for reporting. About only thing I can think of in new gas besides ethanol attach are acetone analogs like MEK, which I don't think is a worry in fuel.
Maybe Carbon will take me up on doing tests with materials I supply, plus his own.
But then how long a test period - ugh.

Good clear filters may give a reserve to know when time to toss or re-make tank.
I will get in habit to check pumps and not to store fuel long, if I'm able from a crash or such. They sell booze in plastic jugs, wonder if that could be applied by solvent that didn't eat tank too.

I think you are correct, Debby. A band aid solution, no matter what you use or how well you prep. With the threat of even higher percentages of ethanol and not to mention the fact that they are illegal in the states, FB tanks will be at the discretion and risk of the user, not that it isn't already.
Contrary to popular belief, ignorance is not bliss.

I applaud your efforts, Hobot, but a survey will always be inconclusive. If there is a failure, how can you be certain it wasn't a failure in application?

35+ years in polymer chemistry including some experience with both Bisphenol A and Novalac Epoxy (Bisphenol F) gives me a little insight to their properties. Carbonfiber makes some good points in theory, but the scientist in me wants to see hard data. There are factors that influence how flexible vs brittle the cured (crosslinked) polymer will be. One is the molecular weight range of the epoxy. The higher, the more flexible and less brittle and vice versa. These are very viscous polymers, so to get something that flows without the addition of solvent, I expect Caswell's is a pretty low molecular weight, which would tend to corroborate CF's theory.

As I have said before, the process of "slosh" coating a tank is risky. Cutting out the bottom, thoroughly cleaning it , and brushing on a sealer is a much better way.

Novolac epoxies are quite solvent resistant, so I would not expect any alcohol (ethanol or methanol) would soften a properly cured system. Any failure with gummy residue in the carbs is either the polyester of the tank or a poorly mixed, poorly cured epoxy. These systems can take days to completely cure, and you should wait at least a week before putting gas in them. These systems are used to coat steel storage tanks that store petroleum products and years ago we made novolac epoxy coatings for storage tanks for distilleries.

As to liquor stored in plastic bottles, next time you get one of those plastic beer bottles, cut it in half. Carefully peel away the layers. You will find at least four layers of different plastic! (but none are epoxy)

Well the last glass tank I did with Caswell was several years ago. It was a really nice Dunstall tank. I cut the bottom out ,ground it to clean solid glass on the inside and built it up on the inside with epoxie based fiberglass that was being sold for boat fuel tanks. I don't remember the brand. Then I ground the surface of that with 60 grit before I epoxied the tank back together. Then I slosh coated it with Caswell. It never actually leaked liquid fuel but it only took a couple years for the fuel to get through and make the surface bumpy and ugly. I removed it before it completely failed and it is hanging in my rafters. Jim

comnoz said:

Well the last glass tank I did with Caswell was several years ago. It was a really nice Dunstall tank. I cut the bottom out ,ground it to clean solid glass on the inside and built it up on the inside with epoxie based fiberglass that was being sold for boat fuel tanks. I don't remember the brand. Then I ground the surface of that with 60 grit before I epoxied the tank back together. Then I slosh coated it with Caswell. It never actually leaked liquid fuel but it only took a couple years for the fuel to get through and make the surface bumpy and ugly. I removed it before it completely failed and it is hanging in my rafters. Jim

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Any idea why you didn't put a coat of Caswells on when you had the tank open?

[q

Any idea why you didn't put a coat of Caswells on when you had the tank open?[/quote]

At the time I was convinced that the boat tank glass was absolutely fuel proof. That was how it was advertised anyway. I just did the Caswells to make sure it didn't do what the glass roadster tank I did before this one did. I used Randolfs alcohol proof sloshing aircraft tank sealer in it. I am glad I was not at 5000 feet. Jim

I have done 4 different tanks w/ caswells (double coating the last 3 of them) - all failed - one took about 3.5 years, but it inevitably filed too - bad thing is is not only does it ruin what ever paint is on the paint, it can also lead to failure of top end

i think Mr fiber is really just reiterating what a lot of people on the forum have stated - barring cutting the tank open and reglassing it it will fail at some point

m

Thats pretty much the case Mike............use of materials which are entirely unsuited for use as a tank sealant , does indeed mean failure at some stage is inevitable!

However use of proper industrial products, that were professionally applied, may well be quite a different story and could provide a long term solution to problem tanks?

mikegray660 said:

I have done 4 different tanks w/ caswells (double coating the last 3 of them) - all failed - one took about 3.5 years, but it inevitably filed too - bad thing is is not only does it ruin what ever paint is on the paint, it can also lead to failure of top end

i think Mr fiber is really just reiterating what a lot of people on the forum have stated - barring cutting the tank open and reglassing it it will fail at some point

m

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You got that right, I have been rebuilding an average of 1 cylinder head a week not counting exhaust thread inserts for the past several years. I have had three heads come to me in the last year where I have had to drive the bent valves out of the guides. All were using tank liners or fiberglass tanks - not necessarily Caswell and not only fiberglass tanks. That is part of the reason I have such a distaste for tank liners or fiberglass tanks. Jim

comnoz said:

You got that right, I have been rebuilding an average of 1 cylinder head a week not counting exhaust thread inserts for the past several years. I have had three heads come to me in the last year where I have had to drive the bent valves out of the guides. All were using tank liners or fiberglass tanks - not necessarily Caswell and not only fiberglass tanks. That is part of the reason I have such a distaste for tank liners or fiberglass tanks. Jim

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and I was poo poo'd on the inoa list for saying the same thing. ALL LINERS WILL FAIL.

and I was poo poo'd on the inoa list for saying the same thing. ALL LINERS WILL FAIL.[/quote]

Well at least they acknowledged your presence. That is more than I usually get. Jim

Alrighty then I'll try to avoid ethanol, pretty easy for a few 100 miles around here and start saving for a new tank and use the eventually ruined one to hold my asses : (

Hm, steel rusts so sealing that might only be stop gap too. I guess I'll look into explosive formed SS, if not ordinary welded up kind.

On the other hand I'm a propane proponent and a couple of 20 lb tanks slung over the spine would go a long ways or store long.

bill said:

comnoz said:

You got that right, I have been rebuilding an average of 1 cylinder head a week not counting exhaust thread inserts for the past several years. I have had three heads come to me in the last year where I have had to drive the bent valves out of the guides. All were using tank liners or fiberglass tanks - not necessarily Caswell and not only fiberglass tanks. That is part of the reason I have such a distaste for tank liners or fiberglass tanks. Jim

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and I was poo poo'd on the inoa list for saying the same thing. ALL LINERS WILL FAIL.

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Thats simply not correct...........the silly untested snake oil liners such as Caswell will most certainly fail, but the type of materials which have been in use industrially for many years, are highly unlikely to cause problems if they are applied properly!

Unfortunately though those who buy this rubbish tend to believe the ridiculous advertising blurb on the packaging, and pour the "sealers" into their tanks, which are then to all intents and purposes scrap.

There is also no reason whatsoever for a properly made GRP tank, manufactured using the correct materials and production methods to cause any sort of problems, and the fact that composite underground fuel storage tanks have been in use commercially for many decades, does strongly support this!

However in common with those supplying tank "sealers" it would appear that most of those producing GRP bike tanks, have no real understanding of how to go about doing this, so failure of a recently made GRP tank is something that is a distinct possibility!

Well I would not say that there are no chemical liners that can handle fuel and its additives. Thousands of correctly manufactured composite tanks buried around the country show they can last for a long time. But I have yet to see a sloshing fuel tank liner stand up more than a few years in a fiberglass Norton tank. Jim

Carbonfibre said:

Thats simply not correct...........the silly untested snake oil liners such as Caswell will most certainly fail, but the type of materials which have been in use industrially for many years, are highly unlikely to cause problems if they are applied properly!

Unfortunately though those who buy this rubbish tend to believe the ridiculous advertising blurb on the packaging, and pour the "sealers" into their tanks, which are then to all intents and purposes scrap.

There is also no reason whatsoever for a properly made GRP tank, manufactured using the correct materials and production methods to cause any sort of problems,

!

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IMHO part of the problem is in the USED tank. as the fuel permeates the glass, now you have a real problem as it will attack from both sides of the liner and you will not achieve proper bonding. the comment was also toward the commercially sold liners ( snake oil peddlers ). when you start talking about NEW GRP tanks it is a different ball game IMO

comnoz said:

Well at least they acknowledged your presence. That is more than I usually get. Jim

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I follow that list BUT to me it is almost a DEAD list. compair the number of daily post's and with Allan's IRON fist you don't dare wander off a norton topic. I am also thinking about not renewing my INOA member ship. IMHO it is the few the proud the stuck up!!

Since hobot started this thread on "caswell" novolac sealer, I wish I knew which formulation they are using...especially since they are getting heat for something they clearly don't manufacture or even have the ability to "test".
You have tokeep things in perspective and remember these norton tanks were probably (who knows for sure?) made with GP polyester resin.
Gasahol was introduced the US in the early 80's and only grew to 7% of the market by 88. Fiberglass storage tanks were introduced before that, but the alcohol problem complicated that industries products. In the early 90's I had used a higher grade Isophylactic resin for my first fastback tank, that was specifically recommended for gas station storage tanks.
My recent purchase of VE resin is about 3X the cost of GP polyester resin. This is in anticipation of making a repop later dunstall tank to replace one who's gp resin and caswell liner has failed. The case of failure will only be determined after autopsy, after the mold making process is finished.

The continum.... On one hand, it is reported that 30+ year old gasohol storage tanks have been industrially tested and recertified. These tanks are gasoline rated with blends up to 100% ethynol !!!!?
Yet on the other hand I have looked for industrial tank coating and have yet to find one that is BOTH gasoline and ethynol rated. novolac VE seems to be the best so far...
My research will continue into these areas:
Tanks *UL 1316 Glass-Fiber-Reinforced Plastic Underground Storage Tanks for Petroleum Products
or ASTM D 4021-92 Glass-Fiber-Reinforced Polyester Underground Petroleum Storage Tanks
These products are claimed to be vinylester.

You should be able to see some of my work at the INOA/NOC rally in july. No guarantee on the results. I am planning on doing a vinylester tank with brush painted novolac liner than joined with araldite 2015 possibly a finish slosh of more novolac over the joint.

:mrgreen:

There is nothing whatsoever to stop any of the snake oil sellers carrying out tests on the repackaged materials they are marketing! Other than the fact that properly conducted tests would show very clearly that these products are not fit for purpose, which obviously wouldnt be likely to do that much to help profits.

Unfortunately there seems to be very little understanding of how to go about either sealing an existing GRP tank (a long term solution is currently impossible using commonly available products, applied at home), or making new GRP fuel tanks that are fully resistant to attack by alcohol bearing fuels.

The error made by those who chose to trust a snake oil type product, is that while materials such as properly cured novalac epoxy resins have very high levels of chemical resistance, they are also very brittle and without suitable filler elements added are almost certainly going to crack after a while, and allow alcohol fuel to come into contact with a very small area of tank surface, which will mean the tank will fail very quickly.

In terms of manufacture of new fuel tanks, there is a great deal of confusion over the most suitable resins to use, and little grasp how important very accurately controlled post cure processing is, or of the correct way to install a chemical resistance layer. Underground fuel storage tanks have been in use for many years, with few problems, but the production process relative to UST's is quite different to that of a motorcycle tank, and not really relevant to making bike tanks.

The above leads to a situation which means all original GRP tanks are likely to fail at some stage if alcohol bearing fuels are used, and in some cases recently produced GRP tanks are also likely to be affected by Efuels, as they simply have not been manufactured correctly. I doubt very much the current situation is likely to change anytime soon though, as anyone with an old GRP tank is likely to believe the ridiculous claims made by the snake oilers, and manufacturing alcohol resistant tanks is not simply a matter of choosing a chemically resistant resin and trusting to luck!