"O" ring compounds for nitro

[glenng]

What o-ring compound will hold up best for nitro/methanol and synthetic oil?

Thanks,

Glenn

 

[Bill Gibson]

What o-ring compound will hold up best for nitro/methanol and synthetic oil?

Thanks,

Glenn

Glenn, i use Viton....dont know if thats the best, but they hold up for me......i take it that heat isnt an issue where you are using them?

 

[tnrcboatracer]

Check out the o-ring material chart on the Parker O-ring website. IIRC, it appears that Neoprene is best for nitro, but not good for oil. EPDM looks pretty good for both, but Viton doesn't like nitro that much. I use EPDM and Neoprene depending on oil content and type. Typically temp is not an issue on the intake side of the motor, especially if it is a remote 3rd channel needle.

 

[glenng]

Check out the o-ring material chart on the Parker O-ring website. IIRC, it appears that Neoprene is best for nitro, but not good for oil. EPDM looks pretty good for both, but Viton doesn't like nitro that much. I use EPDM and Neoprene depending on oil content and type. Typically temp is not an issue on the intake side of the motor, especially if it is a remote 3rd channel needle.

Thanks Bill and Jon, It's been a while since I've checked Parkers website. I think oil will be synthetic@ 15%. Not familiar with EPDM?

Thanks,

Glenn

 

[jetpack]

I think the standard O-ring compound is just the cheap old black Nitrile/Buna-N and thats what I look for.

They are not the softest but they do the job once installed and they are tough enough not to tear trying.

Search for fresh ones because they can age.

the reddish orange Viton's are really soft and I've tried them and they seem to degrade very quickly.

Buna-N's in my carbs are tight at first but after a week or so they compress and pretty much stay there with consistent drag. Then they proceed to harden up where things are smooth and seems its a 50/50 job with the oil helping. Once you disturb those however its best they be replaced.

 

[glenng]

I think the standard O-ring compound is just the cheap old black Nitrile/Buna-N and thats what I look for.

They are not the softest but they do the job once installed and they are tough enough not to tear trying.

Search for fresh ones because they can age.

the reddish orange Viton's are really soft and I've tried them and they seem to degrade very quickly.

Buna-N's in my carbs are tight at first but after a week or so they compress and pretty much stay there with consistent drag. Then they proceed to harden up where things are smooth and seems its a 50/50 job with the oil helping. Once you disturb those however its best they be replaced.

Thanks Jetpack, I think the o-rings you will find at a auto parts store would be the black nitrile or buna-n. All the viton rings I've seen are black and neoprene (or silicone) are reddish-orange.

Glenn

 

[Bill Gibson]

I think the standard O-ring compound is just the cheap old black Nitrile/Buna-N and thats what I look for.

They are not the softest but they do the job once installed and they are tough enough not to tear trying.

Search for fresh ones because they can age.

the reddish orange Viton's are really soft and I've tried them and they seem to degrade very quickly.

Buna-N's in my carbs are tight at first but after a week or so they compress and pretty much stay there with consistent drag. Then they proceed to harden up where things are smooth and seems its a 50/50 job with the oil helping. Once you disturb those however its best they be replaced.

Thanks Jetpack, I think the o-rings you will find at a auto parts store would be the black nitrile or buna-n. All the viton rings I've seen are black and neoprene (or silicone) are reddish-orange.

Glenn

Yep, there are different grades of viton Glenn.....red, black, green, etc......i use the black stuff......the only stuff thats kind of hard on Viton is Alcohol (over time), keytones, and refrigerants.......it is VERY chemical resistant....EPDM is okay too..PFTE is the most resisant of all make ups, but is too hard!

 

[Tony Newland]

no rubber will live forever exposed to nitro and methanol.... pick up bulk of your sizes and replace every so often

http://www.mcmaster.com/

 

[Bill Gibson]

no rubber will live forever exposed to nitro and methanol.... pick up bulk of your sizes and replace every so often

http://www.mcmaster.com/

EXACTLY! Thats the way to do it!!! For the amount of money we spend on this CRAZY hobby, a few bucks for extra O-rings just shouldnt be an issue!

 

[glenng]

no rubber will live forever exposed to nitro and methanol.... pick up bulk of your sizes and replace every so often

http://www.mcmaster.com/

EXACTLY! Thats the way to do it!!! For the amount of money we spend on this CRAZY hobby, a few bucks for extra O-rings just shouldnt be an issue!

Thanks for all the replies guys-now for the curve ball-what durometer reading(relative hardness)? I will go with Jon's choices of materials.

Glenn

 

[tnrcboatracer]

I use the 70 hardness

 

[glenng]

I use the 70 hardness

Thanks Jon, Had a feeling I'd hear from you first. 70 Duro it is! Used the 70 duro Vitons in some offshore drilling tools years ago(1980's). No Nitro( but hi temps). Company used individually inspected(Mil Spec) stuff. Appreciate your input very much.

Thanks,

Glenn