Jabsco manual toilet base-to-bowl o-ring material

[ErikFinn]

I'm rebuilding my manual Jabsco head. Asked the local chandlery for a BASE-TO-BOWL service kit (which was listed on the Jabsco leaflet I got with the major refit kit about a year ago), but chandlery said the kit is no longer available. True or not, but I don't want to go through the hazzle of ordering from abroad, especially as the single main part in the kit is just the o-ring. So I want to try source the main part which is the o-ring, locally.

My question is: provided I manage to find a similar size o-ring will it be usable, MATERIAL WISE?

I do not know what the OEM material is but I reckon if I find an o-ring locally it will be just a regular rubber (?) one, not nitrile or anything fancy.. Would that be a problem, anyone please?

thanks.
Erik

PS. Would be nice to know the material of the original Jabsco o-ring also, I could not find that info by googleing. All I know is Jabsco says to use Petroleum Jelly Vaseline during assembly. Maybe neoprene?

[dlymn]

My guess is that most o rings might be synthetic rather than natural. They are expected to work in some fairly extreme conditions. Your bowl might have some extreme things in it but given the way these toilets are put together, it's unlikely that much fluid will actually touch the o ring..
The petroleum jelly probably makes the best low pressure seal and will protect the o ring. Even natural rubber will give you a good seal for quite a few years. It's not exposed to sunlight, heat nor oxygen and so is in a relatively stable environment.

[JPA Cate]

Pretty sure any o-ring material will do for that application, may be able to find them at a bearing shop.

Ann

[ErikFinn]

I should have mentioned I expect to use muriatic acid (hydrochlorid acid) occasionally and regular household vinegar more often for cleaning, maybe regular toilet bowl gel cleaner but I'm not sure if that is very healthy for the the seals..?
When I disassembled the bowl-to-base joint I could see the o-ring had been exposed to poo.. And the unmistakable smell does not disappear even after a vinegar bath..

[JPA Cate]

Erik, that's what it's like, working on the head. No escaping, no magic smell-impermeable O-ring material that I know of.

Ann

[Jim Cate]

I think any of the common elastomers (viton, nitrile, silicone, buna-n) would work fine in this low stress, low pressure seal. Take the old one to a seal/bearing shop near you, and they will be able to sell you a replacement, or point you to a better source. All such shops that I have dealt with around the world have been pretty knowledgeable and helpful.

Yes, it will be briefly exposed to various mild reagents and some biologicals, but this is pretty much a non-event in the world of industrial o-rings. Don't overthink it!

Jim

[ErikFinn]

Thanks guys, I understand a non-OEM material for this o-ring is not so critical in this application, which is great news for me.

Regarding overthinking, its just in my nature can't help it, sorry..

One last Q about the O-ring, and in particular about the thickness:

In marine toilet applications does a static o-ring's thickness typically shrink, maintain size, or swollen over time and use? This of coures is for an o-ring that sees no movement and friction. Just constant pressure.

As I do not have an original un-used o-ring available to compare to the old used one it would be good to know what happens to it as its being used and sees the occasional muriatic acid, vinegar, deposits, and what have you.. Before I buy and install a new NON-OEM o-ring hopefully for the last time ever.. hehe

I flipped the bowl upside down and put the old o-ring in to the o-ring housing of the base ducting, with some vaseline, so there was no pressure acting on the o-ring (no bowl weight on top of it it), and it looked like the o-ring was protruding only a fraction of a millimeter over the "wall" of the housing, thus suggesting this old O-ring has NOT increased in diameter over the years. If anything, it may have shrunk a bit. Or so I reckon.. In which case I should prefer to get a fraction thicker new O-ring, rather than exact same size or smaller. . Does this sound about right kind of reasoning to you guys?

[dlymn]

O rings usually come in fairly standard sizes. Often they are thin or thick. Take yours to a supplier and get the one that is the same size. If you get a ring larger diameter or too greater thickness, it might not fit snugly into the groove. This can cause kinks in the ring and this will eventually leak. It's a fairly straightforward thing.

In the good old days, this seal might have been done with a form of thin cardboard. I have made many for water pumps and thermostats on cars. (They weren't like o rings but sealed over a larger surface).

[peghall]

I should have mentioned I expect to use muriatic acid (hydrochlorid acid) occasionally and regular household vinegar more often for cleaning, maybe regular toilet bowl gel cleaner but I'm not sure if that is very healthy for the the seals..?

A cupful of distilled white vinegar flushed all the way through the system weekly will reduce, if not eliminate, the need for muriatic acid. Follow each "dose" of vinegar with at least a quart of clean fresh water after about 45 minutes. DO NOT leave vinegar standing in the bowl...soft rubber (joker valve) left to soak in vinegar will swell and distort.

Household chemical bowl cleaners are highly destructive to the rubber parts in toilet pumps. To clean the bowl, use a SMALL amount of abrasive cleanser on a sponge or wet paper towel, wipe it out with a wet paper towel or rinse the sponge first. The tiny amount left when you flush is too little to do any harm.

[TrentePieds]

Quote: "In marine toilet applications does a static o-ring's thickness typically shrink, maintain size, or swollen over time and use?"

Don't even worry about it. Nitile "O"-rings of "appropriate" size are 35 cents a toss at any auto-parts supplier. Buy a dozen - or more, if it'll make you feel better :-)

I couldn't find a perfectly sized replacement, so I took the "next size up" in terms of "thickness", comparing the original and the proposed replacement "by feel", together, twixt thumb and forefinger. I have a "mike", of course. I even know how to use it, but "spurious accuracy" is to be avoided. We just want functionality :-)

The new ring fitted in the groove on the plunger, but was a tad oversize in terms of diameter. I spoke sternly to it after having slipped it on the plunger and convinced it that it really, really wanted to slip down the bore of the tube without giving me lip. It did so. The pump action feels better and IS better now than it was before. You work out the physics of why that is :-)

There are times when buying "marine" grade stuff is the right thing to do. Buying "Marine"-grade nitrile "O"-rings from Jabsco distributors is not one of them!

An "O"-ring re'n're is - literally - a five minute job. No need to get "intellectual" about it :-)

TrentePieds

[rwidman]

Have you considered contacting Jabsco and asking them if the O ring is available or if not, what can be used in its place?

[ErikFinn]

I'm attaching a photo showing the old and new Joker Valves and Base Valve Gaskets. Deformed and lost retaining washer have caused separation of the metal weight on the Base Valve Gasket. Maybe these photos explains why I'm being so anal about this simple o-ring. Another thing I mentioned the local chandlery told me the kit is no longer available. ( but I do reckon it actually is, the chandlery guy just being lazy, rather.. and like I said I do not want the hassle of ordering from abroad, ie. the from the civilized world)

Some folks think you can just walk in to any hardware shop or autoparts shop and get a substitute. Yes, in the civilized world, but not so in the boonies here. And the local shops are not in the internet age yet so no luck there. Trying to search for anything out of ordinary here in the boonies could take days and still no luck if you do not know a particular specialist shop. I mention o-rings, SS bolts and nuts, quality electrical items to name a few. Sometimes I miss the developed world as you can get anything, just google and go pick it up or have it delivered in a day or two. But you can not get a delicious meal for a dollar or two.. Fortunately I have a local car mechanic friend who will take me to a specialist shop and hopefully I'll get a substitute o-ring next week.

I did notice the old o-ring is a bit flattened. I can not see it with my bare eyes but it can be felt when rolling the ring in between two fingers; it definitely is flattened a bit. So I will have to take that into consideration when checking out the local o-ring shop.

The other photos: the bowl has a slight manufacturing flaw: the outer surface is not level. About 90 degrees on the outer wall is lower than the rest 270 degrees. that's what the two funny photos with the torch in the back are trying to depict. (I know the photos are inverted, sorry I don't know how to re-invert them, they are correct in my camera.. I'll ask the tech-help..)

The other photo is showing the bowl's contact surface with the o-ring; if one looks carefully enough one can see the black circular stain left by the old o-ring; that is where the old o-ring used to sat, and it was not very well positioned, about two inches had been hugging the edge of the contact surface, compromising the seal. and the o-ring had leaked. Therefore it is imperative the bowl and the base are perfectly aligned when assembling them back together.

Thanks for advice and contribution all, that's what makes this forum so great!

[ErikFinn]

Originally Posted by peghall

A cupful of distilled white vinegar flushed all the way through the system weekly will reduce, if not eliminate, the need for muriatic acid. Follow each "dose" of vinegar with at least a quart of clean fresh water after about 45 minutes. DO NOT leave vinegar standing in the bowl...soft rubber (joker valve) left to soak in vinegar will swell and distort.

Household chemical bowl cleaners are highly destructive to the rubber parts in toilet pumps. To clean the bowl, use a SMALL amount of abrasive cleanser on a sponge or wet paper towel, wipe it out with a wet paper towel or rinse the sponge first. The tiny amount left when you flush is too little to do any harm.

Thank You so much Peg, really important and useful information!

[ErikFinn]

Reposting two photos again, hopefully upside up this time..

[01kiwijohn]

Go to a Hydraulic Equipment supplier for the O Rings. They have an assortment of sizes, and durometers ( Hardness) and will have something that will seal properly, and outlast you.