Prist with AvGas

[seethru]

I'm looking for any experience anybody has had with using an additive, such as Prist, with AvGas.

We recently had a loss of power in both engines of our 414. After lengthy investigation into the cause of the power loss, the only remaining cause is fuel line blockage due to ice crystals in the AvGas.

I know this is not common in piston aircraft, but it is possible (and certainly has not been seen by us before this).

Anyway, back to the question... has anybody had to use Prist with AvGas?

If so, how often did you use it? Did you have to be careful about not leaving fuel mixed with prist in your plane for a long time? Was supply of the product readily available or did you pretty much have to carry a can or two along with you wherever you went?

Just curious because we've never had to deal with Prist before.

Thanks.

 

[avbug]

Prist is used with avgas the same way it's used with jet fuel, in the same concentrations. The most common failure with prist is failure to properly mix it during fueling. It has to be mixed with the fuel as it's injected into the tank, otherwise the prist settles to the bottom of the tank where it does little good.

You need to ensure that the fuel is moisture free to begin with, as well as the tanks and fuel system. You can't have water in there and hope for the prist to prevent icing.

The reason prist is seen more often in turbine fuels is that kerosine suspends moisture much better than avgas; it doesn't settle out as quickly and it's harder to detect. The higher fuel flow rates of turbine engines also mean that water is a lesser threat, when given the same quantities.

Use of prist isn't normally required in avgas, but if you're intending to use it, you should probably carry some with you. It's available where jet fuel is sold, but often as not, it's either tank batched in the truck, or sold premixed...you may not be able to get cans.

 

[propsarebest]

If you add it to your airplane using the cans, be sure to wear gloves when fueling. That stuff is real nasty.

 

[Princedietrich]

I concur. From what I understand of the stuff, not only does it reek to high-heaven but it's corrosive and carcinogenic. If you get any of it on you, even the slightest little bit, wash it off of you ASAP. If you get it on your clothes, change them ASAP.

 

[avbug]

It's not good to get in your eyes, but your hands won't fall off if a little gets on your skin. Simply wash it off.

 

[Buckeye]

Prist has been reformulated, it is only classified as a hazmat when sold on pressurized cans. Prist itself falls under ORM. The chemical itself is non-toxic and now harmless. We had an issue a few years ago that involved PRIST, inc and yes the newer stuff is not like the older stuff.

http://www.csdinc.org/prist/

And for you over achievers here is the MSDS link:

http://www.csdinc.org/prist/msds.html

 

[TWA]

If you are able to get it in cans at the fbo, make sure they are the LOW FLOW cans. Jet and Avgas pumps do not pump at the same rate, with Jet normally being higher than Avgas. If you use a HI FLOW can with an Avgas pump, you will almost definitely end up with an over concentration. Most places that have prist in cans only have HI FLOW, so it is best to carry your own with you. We had an issue involving a saratoga wanting prist this past winter, and the above is what the prist help line told us.

 

[Princedietrich]

No, your hands won't fall off if it gets on your skin.

But after a while it'll feel like a sunburn on top of poison ivy.

 

[seethru]

... it'll feel like a sunburn on top of poison ivy.

Note to self: Don't forget to wash hands, and stand upwind if possible.

Thank you all for the information. It's been really helpful.