Opinions on 'best' lube for a spring piston?

[UlteriorModem]

I have heard so many different things my head is spinning.

I saw one guy that made a mix of silicone grease with silicone spray to make it thinner.

I see Moly Paste recommended, though some say it will diesel / detonate.

Just like to hear some of your thoughts on what is best?

Personally I kind of like the silicone approach, so I am pretty sure that is wrong

[Bryan Heimann]

Old school would be moly paste.  Good moly is my favorite.  ARH is really all I have used, although I am pretty sure Mrs. Clause got me some of the Air Venturi brand for Christmas

If you are careful and prepare the rifle properly (meaning, debur, then clean clean clean!) and you don't get it in front of the piston seal,  the moly will not deisel.  At least not enough to notice, not even enough to effect accuracy.

A lot of other guys on the forum use Krytox.  Seems popular with HFT shooters, and supposedly will not deisel or burn at all.  If not good proper moly and tar, then Krytox is probably the way to go.  I'll let someone that has actual experience with Krytox tell you more.

[DanD]

I'm a fan of moly.
With Krytox, you are supposed to degrease everything and not mix it with other lubes. With moly, i just wipe the parts clean and lube em up. No worries if my home tune needs a little tar to dampen vibration.
That said, i did my HW50S with a Vortek kit and Krytox and it runs fine. Normally I'm too cheap to buy kits and I'm not a machinist, so it's moly and tar on most of my guns.

[VillageSniper]

 I thought I read that silicone grease or silicone oil won't protect the metal, like when hardened rear of the piston skirt is rubbing the inside of the receiver when you cock it.  I have had good luck with moly paste buffed into  the cleaned  reciever and applied to the the rear of the piston, then a grease on the spring and guide like euro tar.  The synthetic seals probably don't need lube, at least not like the leather ones of old.  Macarri sells lube and I remember seeing Walther had a moly piston grease and a moly spring grease.  The trick is to wipe out the compression chamber and reciever really well of any excess moly paste, leaving  just a  micro film, before pushing the seal home as it will squeegee  any excess forward, repeat and clean face of seal if necessary before adding any to the piston skirt. And make sure the transfer port is clear as well. 

Vs

[TF89]

Have good luck with both. Krytox and ARH molly

[Bryan Heimann]

I have also read that plain, pure silicon oil won't protect metal from other metals.  But most of the time it is only used as a piston seal lubricant, for installation or maybe occasionally theough the t port.  Personally I don't believe a properly lubed rifle with synthetic seals EVER needs lube for the piston seal. But leather seals need to be kept oiled.

In the GTA Library you can find information on how to do a Super Tune.  In those instructions, superlube with ptfe is used in the compression chamber adter it has been properly honed.  As far as I know, that is a silicon grease with PTFE in it.

Personally, on my own guns, moly to the piston and on the ends of the spring, maybe some tar on the spring or maybe not, and that is good enough for me.

I have done home tunes with moly and tar that resulted in single digit velocity spreads with just a couple of Chinese springers.  So, for sure, it can be done without erratic velocities caused by deiseling.  Whether or not some slight but consistent deiseling occurred, I could not tell you, but if it did I'll take it with a single digit spread all day.

Your mileage may vary!

[Roadworthy]

Since this is only an opinion poll but seems to deal more with practice, I have found I like to burnish the compression tube, piston, seal, etc. with moly powder.  I then put some Krytox on the piston seal lip.  I use Krytox in the cocking slot as well.  I have been wiping factory grease out of break barrel pivots and install moly powder.  I finish with a drop of oil on the cocking lever pivot.  I like Krytox for the barrel latch.

[nced]

I have heard so many different things my head is spinning.

I saw one guy that made a mix of silicone grease with silicone spray to make it thinner.

I see Moly Paste recommended, though some say it will diesel / detonate.

Just like to hear some of your thoughts on what is best?

Personally I kind of like the silicone approach, so I am pretty sure that is wrong

I don't use any type of silicone lubes for steel. Silicone works well for lubing rubber and plastics but can lead to galling between steel parts.

I prefer non-dieseling Dupont Krytox GPL205 grease and Kryutox GPL 105 oil.............


Traditionally molly paste has been used for lubing springers, however they do have some disadvantages.
1. According to some tests......


2. The carrier for the molly powder is usually petroleum based which will diesel if it migrates (or is placed) past the piston seal.

3. The petroleum carrier in molly paste does outgas and becomes thicker with age. Matter of fact, I've been inside springers that were lubed with molly paste that was so thick from outgasing that it was "chunky". Here is a tub of molly bearing spring tar from years ago (when I used molly lubes) that became so thick sitting in a closed container that a socket head cap screw was supported on the edge of the container by a couple "half threads" embedded in the grease.........
 


Some of my airgun parts lubed with non-dieseling Krytox........

[Doug Wall]

I have heard so many different things my head is spinning.

I saw one guy that made a mix of silicone grease with silicone spray to make it thinner.

I see Moly Paste recommended, though some say it will diesel / detonate.

Just like to hear some of your thoughts on what is best?

Personally I kind of like the silicone approach, so I am pretty sure that is wrong

I don't use any type of silicone lubes for steel. Silicone works well for lubing rubber and plastics but can lead to galling between steel parts.

I prefer non-dieseling Dupont Krytox GPL205 grease and Kryutox GPL 105 oil.............


Traditionally molly paste has been used for lubing springers, however they do have some disadvantages.
1. According to some tests......


2. The carrier for the molly powder is usually petroleum based which will diesel if it migrates (or is placed) past the piston seal.

3. The petroleum carrier in molly paste does outgas and becomes thicker with age. Matter of fact, I've been inside springers that were lubed with molly paste that was so thick from outgasing that it was "chunky". Here is a tub of molly bearing spring tar from years ago (when I used molly lubes) that became so thick sitting in a closed container that a socket head cap screw was supported on the edge of the container by a couple "half threads" embedded in the grease.........
 


Some of my airgun parts lubed with non-dieseling Krytox........

Nced, That tub of what you say is moly, doesn't look anything like any moly grease that I have ever used. I'm pretty sure that that is spring tar. I've used Honda Moly Grease, and spring tar for years, with very good results. I would certainly also expect that the Krytox camp is also a good direction.

[DanD]

Nced, That tub of what you say is moly, doesn't look anything like any moly grease that I have ever used. I'm pretty sure that that is spring tar. I've used Honda Moly Grease, and spring tar for years, with very good results. I would certainly also expect that the Krytox camp is also a good direction.

I agree with Doug. The "Ht" marking on the lid = "Heavy tar."

[EMrider]

Either moly or krytox (aka, ultimox 226 on Amazon) work well and I have a hard time objectively saying which is “better”.

I’d probably give a slight nod to the krytox because it does not diesel, but you have to invest some time up front in removing any/all grease from internal parts.

R

[outdoorman]

Nced, That tub of what you say is moly, doesn't look anything like any moly grease that I have ever used.

  He didn't say it was "moly grease", he said it was moly bearing spring tar.

For me, I use Krytox. It works fine and removes the issue of dieseling altogether.

[nced]

Nced, That tub of what you say is moly, doesn't look anything like any moly grease that I have ever used. I'm pretty sure that that is spring tar. I've used Honda Moly Grease, and spring tar for years, with very good results. I would certainly also expect that the Krytox camp is also a good direction.

I agree with Doug. The "Ht" marking on the lid = "Heavy tar."

Yep....it's the "heavy tar" I bought from Maccari years ago. The point of the "thick tar" was the simple fact that when I was using "molly lubes" that tub of "tar" was reconstituted a few years ago to restore the origional thickness (using mineral oil) and the stuff re-thickened over a couple years even though the lid on the tub wasn't opened again. Point being, the petroleum base lube of the molly lubes do get thicker over time as the petroleum base outgasses.

After having "temperature related poi shifts" at a spring field target match decades ago when there was a club near Harrisonburg, VA. The sight in was done during snow flurries but the match ended with temps in the upper 50s. Both my brother and I were shooting .177 R9s and we both had a 1" poi shift at only 20 yards with the higher temps. After that match I stopped using "heavy tar" and only used molly paste (considerably thinner consistency) for internal lubing which did reduce the "temp related poi shifts" during late fall WV squirrel hunts a bit. I then realized that molly paste will also "cake up" after a while so it was imperative to  PROPERLY apply the paste making sure that there were no lumps on the metal surfaces.

Last year I worked on a "tuned" HW springer and this is what I found when I pulled the piston...........

Looks like the "goop" actually had graphite added in the mix (considering the color) and the lube was obviously "copiously applied" by the "tuner" and the "goop" was indeed "gumming up the works"!