I bought some rubber fuel hose from Tractor Supply for my B100 aux fuel tank. The guy did not know what kind of rubber it is but he was emphatic that it was NOT Viton. He says it is compatible with Diesel and BioDiesel because he uses it with B100 in their shop. However, I don't believe him since he may have been using Viton rubber and just not realize it.

Anyways, I bought the hose. I cut a small piece and immersed it in my homebrew B100. 3 days and counting and there seems to be no effect. The host is still firm and solid. It is not breaking apart.

I've seen how B100 eats thru ordinary rubber when I started using a Walgreens bought plastic syringe with rubber plunger in my titration kit. The rubber plunger was disintegrating after less than an hour.
My question is; How long does it take B100 to eat or soften non-Viton rubber? How long must I wait in my Immersion test before I can confidently declare that this rubber is compatible with Biodiesel. I am eager to install the hose.

Jojo

This is an almost impossible question to answer. There are literally hundreds of different "rubber" compounds (most are synthetic compounds, not natural rubber). All with varying levels of resistance to different compounds.

I can almost guarantee the hose you bought was not viton. If it cost less than 10 dollars a foot, I know for sure it wasn't true viton. But, it may well be a very good grade of rubber that will last quite a while with B100. It also depends a lot on the quality of the biodiesel. If it is home-brewed stuff with any residual methanol in it, it will go through hoses pretty quick. If it's spec, washed, fuel with no methanol in it, even cheaper grade rubber will last some time (months, not days anyway).

This is an almost impossible question to answer. There are literally hundreds of different "rubber" compounds (most are synthetic compounds, not natural rubber). All with varying levels of resistance to different compounds.

I can almost guarantee the hose you bought was not viton. If it cost less than 10 dollars a foot, I know for sure it wasn't true viton.

X2
Even cheap fluorocarbon (Viton is a DuPont trade name) 1/4" -3/8" hose would be in the neighborhood of $10 a foot. If it were less than that, you got NBR or SBR hose- probably NBR.

X2
Even cheap fluorocarbon (Viton is a DuPont trade name) 1/4" -3/8" hose would be in the neighborhood of $10 a foot. If it were less than that, you got NBR or SBR hose- probably NBR.

It is a given that it is not Viton. The guy said it was not Viton and on that regard, I believe him.

If it is not Viton, what could it possibly be? and How long will it likely last. Of course, I can not expect anybody to know for sure, I just want guesses of what kind of rubber it is, and given your guess - to guess of how long it will last.

What is NBR and SBR? If it is either, how long will it last?

...However, I don't believe him since he may have been using Viton rubber and just not realize it.


It is a given that it is not Viton. The guy said it was not Viton and on that regard, I believe him.


Your original question stated you didn't believe him. That is why we responded as we did, saying it for sure wasn't Viton.

NBR=nitrile rubber, n-butyl rubber

SBR=butyl-s rubber, buna s, styrene butadiene

Nitrile is pretty good against most hydrocarbons and vegetable oils. Esters will eventually go through it, depends a lot on pressure, temperature, specific formulation, etc. Styrene butadiene won't stand up long to even petrol diesel, so I doubt that is what you have. I'd bet on nitrile, and it should last quite a while if you have spec biodiesel. Another caveat to think about for an auxilliary tank, assuming it is in the bed, is UV resistance. UV exposure will degrade the hose from the outside while the ester is degrading it from the inside.

I'm not up to speed on my bio chemistry, but I do know rubber... Spent the better part of 5 years as a fluoropolymer (type of viton or FKM) engineer.
Is bio technically considered an ester?
Here's a good link to see what compounds are compatible with your fluids. See the section on fluid compatibility.
http://www.parker.com/o-ring/Literature/07-5700.pdf

Is bio technically considered an ester?
Here's a good link to see what compounds are compatible with your fluids. See the section on fluid compatibility.
http://www.parker.com/o-ring/Literature/07-5700.pdf (http://www.parker.com/o-ring/Literature/07-5700.pdf)


Yes, biodiesel is a fatty acid ester. Generally a methyl ester, but doesn't have to be.

That's a good link, I'll have to bookmark it.

Good thing I havent been using Bio as a "personal" lubricant, otherwise I might have a bunch of little bastards running around...):h

Your original question stated you didn't believe him. That is why we responded as we did, saying it for sure wasn't Viton.




Sorry, after rereading my post, it was indeed unclear as to what I believe or not.

I believe him that it was not Viton. What I did not believe was that they were using the same kind of rubber hose on B100. I was thinking that they may have been using a different kind of hose (one made of Viton) and he simply did not realize it.

Anyways, thanks for the info on rubber types. That is what I was looking for.

Jojo