beware of neoprene

[wingski]

Hi guys. Well, the leaking gas gauge is fixed, and I want to warn you about neoprene gaskets. If you have a new gas gauge, and you think there is a possibility that there is a neoprene gasket in there. Beware! There is a really good possibility that that gasket is going to turn to goo, and all of a sudden in the middle of nowhere you’re going to have gas runnining down the front of your instrument panel and down and out the front of the speedometer cable tunnel and on to your foot. That is extremely dangerous because of the wiring the gas comes in contact with, and the fact that you might have a pants leg and shoe soaked in gas.

I was lucky, if you call it lucky having gas all over the place, and the gasket gave out when I was working on the car. I don’t think that thing had been in the car that long. Probably about a year, maybe shorter. If I had known it was in there, I would have made a tool to remove the gas guage retaining ring and replaced that gasket right after buying the car.

I didn’t use cork, but I did use gas proof gasket material and coated both sides with Permatex on the gas tank side of the gauge . It took me awhile to get all the neoprene out of the threads and off the lip of the gas tank. I used a small wire brush in a drill to really clean that opening and those threads and vacuumed any crap that got into the tank . I wanted to make sure the retaining ring screwed all the way in against the actual gauge. Another thing, there was no thin brass washer on the side facing the driver. I removed an old gauge from a spare gas tank that I have. It had three thin brass washers, but I only used one of them so the ring would turn on the guage without turning the actual gauge. However, I had to make another tool to hold that gauge in place while tighteneing that ring, And man, I really made sure that ring was secure against the front of the gauge.

I had to share this because I don’t want it to happen to any of you,

Mike

[Benson]

This neoprene problem is just as dangerous and likely to happen at any time, when used as gasket in the cast aluminum sediment bowls.

The first time that you remove the bowl, the gasket will be all "mushy" and impossible to reinstall ...

if this happens on side of road you are stranded unless you have a cork gasket to use!

I did not just read about this ... it actually happened to me many years ago and several folks I know.

It is not necessary to use more than a VERY thin coating of gasket sealer on CONTACT surfaces ONLY. Gumming up the threads is not needed.

[cpf240]

Just a note of caution.. vacuums and gasoline vapors don't mix well, in general...

[2manycars]

I am puzzled as to why the vendors still supply that rubber gasket in the guage repair kit. It is junk and always has been. This is really a safety issue.. Use cork only.

[BillEbob]

Originally Posted by wingski

Hi guys. Well, the leaking gas gauge is fixed, and I want to warn you about neoprene gaskets. If you have a new gas gauge, and you think there is a possibility that there is a neoprene gasket in there. Beware! There is a really good possibility that that gasket is going to turn to goo, and all of a sudden in the middle of nowhere you’re going to have gas runnining down the front of your instrument panel and down and out the front of the speedometer cable tunnel and on to your foot. That is extremely dangerous because of the wiring the gas comes in contact with, and the fact that you might have a pants leg and shoe soaked in gas.

I was lucky, if you call it lucky having gas all over the place, and the gasket gave out when I was working on the car. I don’t think that thing had been in the car that long. Probably about a year, maybe shorter. If I had known it was in there, I would have made a tool to remove the gas guage retaining ring and replaced that gasket right after buying the car.

I didn’t use cork, but I did use gas proof gasket material and coated both sides with Permatex on the gas tank side of the gauge . It took me awhile to get all the neoprene out of the threads and off the lip of the gas tank. I used a small wire brush in a drill to really clean that opening and those threads and vacuumed any crap that got into the tank . I wanted to make sure the retaining ring screwed all the way in against the actual gauge. Another thing, there was no thin brass washer on the side facing the driver. I removed an old gauge from a spare gas tank that I have. It had three thin brass washers, but I only used one of them so the ring would turn on the guage without turning the actual gauge. However, I had to make another tool to hold that gauge in place while tighteneing that ring, And man, I really made sure that ring was secure against the front of the gauge.

I had to share this because I don’t want it to happen to any of you,

Mike

Ditto! I was luckier than you -- had just bought the car and could smell gas when filled to "FULL." I know what Ethanol has done to the carburetors in my two Mustangs (had to rebuild every 6 months!) and one caught fire from a leaking accelerator pump diaphragm! All due to ethanol.

I too discovered that the neoprene gasket in the Vicky was turning mushy and like Mike's, the threads were a pain to clean up properly. I replaced the whole gauge with one from Bert's which included a cork gasket.

Several people told me that no Permatex was necessary, but that seemed illogical to me so I went ahead and used it in the application.

I think I will be very happy with this new setup.

Bill

[JDupuis]

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Thanks Mike, Very informative and a great reminder of future repairs some of us here in the barn may need to perform. . Jeff

[JDupuis]

Originally Posted by cpf240

Just a note of caution.. vacuums and gasoline vapors don't mix well, in general...

Worth stating twice. Thanks cpf240. Jeff

[Dick Steinkamp]

If you actually have a gasket made out of neoprene, it has satisfactory resistance to ethanol, but unsatisfactory resistance to gasoline...

http://mykin.com/rubber-chemical-resistance-chart-3

Neoprene should never be used with gasoline, and I don't think it is ever sold for use where it can come in contact with gasoline (at least by a supplier that wants to avoid an expensive judgement).

Could it be that some call any black rubber like gasket neoprene?

[1930-Pickup]

Originally Posted by cpf240

Just a note of caution.. vacuums and gasoline vapors don't mix well, in general...

...and a drill motor! They typically have sparks at the brushes.

...and that wire brush used on the threads...not steel I hope.

[Dick Steinkamp]

...

[1930-Pickup]

Originally Posted by Dick Steinkamp

...

.

The vacuumed air (with fuel vapor) is drawn near the electric motor of the vacuum cleaner. The electric motor sparks at the brushes.

[JDupuis]

Hey Dick, do a youtube search. Some people have used a vacuum to clean rust particles from gas tanks, but if the tank still has combustible fumes in it, it turns into a fire ball. Jeff

[Dick Steinkamp]

Yea...I get it. I deleted my post. I finally figured out that vacuum CLEANER was meant by the poster. I couldn't see out how a vacuum was a problem with gas vapors.

[Pete]

Originally Posted by Dick Steinkamp

If you actually have a gasket made out of neoprene, it has satisfactory resistance to ethanol, but unsatisfactory resistance to gasoline...

http://mykin.com/rubber-chemical-resistance-chart-3

Neoprene should never be used with gasoline, and I don't think it is ever sold for use where it can come in contact with gasoline (at least by a supplier that wants to avoid an expensive judgement).

Could it be that some call any black rubber like gasket neoprene?

Which chart are you going to believe??
Even this one has a few inacuracies. I have run nitromethane against Neoprene many times with no bad affects.

http://www.kelco.com.au/wp-content/u...lity-guide.pdf

Geniune Neoprene has been used for O-rings and gaskets in gasoline environments for many years.
Who knows what you get from china.

[daveymc29]

No expert here, but I found that there are at least two thicknesses of cork gaskets sold for the gas gauge. For me the thinner one worked the best and easiest in the few cars that I have changed the gaskets on. I found the black gaskets do turn gooey, but am no chemist so I have no idea what they are made of, but our gas makes them react strangely, not in a good way.

[ursus]

Originally Posted by cpf240

Just a note of caution.. vacuums and gasoline vapors don't mix well, in general...

I can certainly attest to that! A friend was helping me remove a gas tank from a 1930 coupe. He noticed the sound of debris rattling around in the tank as we moved it to the ground. After the struggle of removal, I was gathering up the various fasteners and he decided to vacuum out the interior of what we thought was a dry tank. Fortunately, the canister shop vac had a 20 foot hose. BOOM, the explosion split the metal tank like an egg and sent the rest into the neighbors yard. My friend was left holding an extension piece and with an expression that was priceless. The neighbors were not amused.

[JDupuis]

Ursus: message received! Good to know that he "lived" and "learned".
Jeff

[Marshall V. Daut]

Well, the way that people here are jumping on the "Death to Neoprene!" bandwagon, I have to believe something has drastically changed in recent times. For years I have been using the neoprene gas gauge gaskets without any problems due to leakage or gooey gaskets. For YEARS. For so many people on this website to now espouse the use of ONLY cork and avoid Neoprene, I have to believe something has changed:
(1) The composition of the Neoprene gaskets offered today has been altered or substituted with an inferior material similar to Neoprene, but without its gas-resistant qualities;
(2) The ever-changing formulae for today's gasolines have been altered enough to now interact with Neoprene in a negative fashion. I'm looking at YOU, Ethanol!
(3) You all own stock in cork companies.
I'm leaning towards #2, although it could also be a combination of all three suspicions. Even though I live in Iowa and our farmers benefit from growing the corn used in blending Ethanol fuels, I religiously avoid using that cr*p in my vehicles, modern and antique. There are a few gas stations around here offering gasoline that is not Ethanol. They get our family fuel dollars. It could be that with the daily degradation of fuels in this country, what we are now obliged to use in our cars is no longer compatible with what the Model A parts vendors are selling as Neoprene gaskets.
It's hard to get around the fact that Ford used cork in Model A gas gauges from Day One and that it held up well for years, if not decades. For the purists in the crowd, cork is the only way to go. But as anyone who has fully restored a Model A can attest, cork has its own warts and hairs, and doesn't last forever. It deteriorates, shreds and flakes apart, usually ending up in the bottom of the gas tank. That explains why so many on/off valves in non-indented firewall Model A's end up with so much crud in them that they impede fuel flow to the carburetor. Most of that crud is failed cork from the gauge's float. For those of you who think cork is the magic bullet for resisting gasoline, how many of you have seen floats like the one in the picture below during your restorations?
I can think of at least four Model A's that I have installed Neoprene gas gauge gasket kits in the last two years and no owners have come back complaining about leakage. Like any gasket material, however, you do need to go back occasionally and check the tightness of the outer and especially the inner trim rings. If these loosen due to vibration and time, the gasket material beneath them expands and comes directly into contact with air and fuel. That may be where we can trace complaints about failing Neoprene in gas gauges.
'Dunno anymore. I'm confused by the almost virulent attacks on Neoprene that I'm reading here because my experience has been just the opposite. And no, I don't own any stocks in Neoprene companies. I am admittedly not a chemist and I'm just as unhappy with the horsesh*t gasolines we are compelled to buy these days as you all are. I can only recommend to avoid Ethanol and its evil derivatives, present and future. That corn syrup fuel cannot be good for any car in the long run. Even the mileage is lowered using this junk.
So, use what you feel is best in your Model A's: cork or Neoprene. Until I see conclusive proof that Neoprene is no longer compatible as gasket material in contact with gasoline, I personally prefer it compared to some really poorly-made cork gasket kits I have received over the years.
Marshall

[Dick Steinkamp]

Originally Posted by Pete

Which chart are you going to believe??
Even this one has a few inacuracies. I have run nitromethane against Neoprene many times with no bad affects.

http://www.kelco.com.au/wp-content/u...lity-guide.pdf

Geniune Neoprene has been used for O-rings and gaskets in gasoline environments for many years.
Who knows what you get from china.

I agree with Pete. There is often conflicting "facts" on the internet.

Here's one more that says neoprene should not be used with gasoline but can be used with alcohol.

http://www.manuf-rubber.com/wp-conte...rial-Guide.pdf

Bottom line...you are free to believe what you want to believe. Either from your own personal experience with the product or the "facts" from the source you feel most credible.

Again, I'll just throw out there that perhaps like Kleenex and Xerox, we (and some suppliers) call most any black, rubber gasket or O-Ring "Neoprene" when it may actually be Nitrile, Viton, or a number of other similar LOOKING products. Some that work well in gasoline and some that don't.

[wingski]

Thanks guys, I appreciate your concern about me blowing myself into the next county. However, I did take precautions. The small circular brush I used in the drill to clean out the threads and the lip of the gas tank was brass not steel. And, I used an attachment for cleaning keyboards to suck up any debris on the other side of the gas tank lip. I angled that little plastic tube thing down and touched metal on the inner side of the lip. Then, I’d stick my forefinger into the hole and rub any loose stuff around. Then, I’d vacuum again.

I know it sounds stupid to use a vacuum around a gas tank, but I sure didn’t want any crap getting into that tank, and I really was very careful. I wasn’t worried about sparks from the drill itself because that brass wheel was a little bit bigger than the opening, and I don’t think I was sucking any fumes.

I would have plugged the hole or used masking tape, but I had to get that lip really clean so a gasket would seat correctly. Also, I sure didn’t want a rag or masking tape getting into the tank.

I was careful,

Mike