Wacker P-12 Paste

[mcomeaux53]

Where do you purchase this item or is there an alternative?

[Dave S]

mcomeaux53,

One of the list advertisers, LEAF (a Rotax dealer), Located in Wisconsin has two sizes of the heat conductive paste.... they sell .14 gram packets or a larger tube (the larger tube costs a lot and more and is more than a person needs unless they are a shop). I recently bought two of the .14 gram tubes...one tube is more than enough for doing the threads of a set of spark plugs.

Any Rotax service center should have it. CPS in California for example.

Sincerely,

Dave S
KF7 Trigear
912ULS Warp Drive
St Paul, mn

[dholly]

Not interested in sparking any sporting discussion and everyone is free to do/use whatever they want, including no paste at all, so YMMV.

It is the same thermal heat sink grease used in electronic equipment and readily available in the aircraft supply aisle of your local RadioShack store. A $5 tube will provide enough for two or three plug changes on a 912.

There will be critics to using other than the Rotax recommended paste so here is some related info copy 'n pasted from the Rotax-Owner.com forum:

Both the wacker P12 and the radio shack thermal paste are very high high quality products. As are probably dozens more on the marketplace.

The P12 and the Radio Shack products are made from a silicon grease vehicle with zinc oxide and silver added as a conductor.

The P12 has a conductivity rating of 0.81 W/mk and a working range of -22 to +392F.

The Radio shack product (made by NTE electronics) has a conductivity rating of 0.80 W/mk and a working range of -40 to +400F.

Neither product is made specifically for aircraft engines, but for electronic heat sinks.

Both products are almost identical in specifications and both will do the job. The whopping big difference is the price and availability of the products.

[Danzer1]

Micro Center also carries a huge selection of thermal paste/grease/compound in a variety of sizes: http://www.microcenter.com/category/...Compound-Paste

[Dave S]

The other deal I have wondered about is the potential use of the aluminum paste anti-sieze compound for automotive purposes on the Rotax spark plugs.....the stuff is normally used to prevent pulling the threads on aluminum cylinder heads on car motors (steel plug threads vs aluminum head threads).

With the high aluminum content, it should conduct heat well; although, it normally uses an oil base carrier rather than silicon but that does not seem to be a problem with high temp applications on cars.

Anyone ever use this stuff?

Dave S

[jrevens]

The Champion product sold for aircraft use is also oil-based, with graphite, which is electrically conductive. Obviously, with any of these products, you have to use them carefully & sparingly to avoid shorting out a plug. With Rotax, is the primary reason for use heat-conduction or anti-seize, or both?

[Dave S]

John,

I have never heard a real definitive discussion on the basis for Rotax's use of the paste; although, I recall reading "somewhere" it was primarily for enhancing heat dissipation from the plugs - if that is the case, it would probably work with the heat range of the normally selected plug......my motorhead intuition tells me the whole business with the paste is a very, very fine point in the first place.

Sincerely,

Dave S

[dholly]

With acknowedgements to the OP's, more copy 'n paste from the Rotax forums:

Since things like plug threads are not zero tolerance the paste fills in the small gaps within the threads. The chemical compound helps heat between dis-similar metals equalize. If the threads were a zero tolerance you wouldn't need a compression ring to keep them from leaking.

The second help for the plug threads is it will lubricate them and help reduce the chance of galling from combustion particles that can and do enter the threads upon removal and insertion. The spark plug torque is based on a wet torque and compression ring compression and without any paste that changes.

Factory testing shows that the Wacker P12 paste reduces the spark plug temp by 10C.

[Dorsal]

I use Permatex Aluminum anti seize and change plugs every 100 hrs, seems to work well.

[Stainbrook]

Where do you purchase this item or is there an alternative?

Hey Mcomeaux, do you know where this is for sale anywhere?