HW95 Dieseling issues

[ShakerT44]

Bought a 95 a few months ago. Shot about 2500 pellets through it with only minor dieseling during the first 100 shots. Purchased a vortek kit and installed it using the grease they supplied in the kit. The rifle kept dieseling past 250 shots so I bought some krytox 205 and cleaned out the gun again with brake cleaner followed by multiple paper towels on a rod and finished off with some simple green. Rifle still dieseled after 100 shots. Took it apart again and cleaned out all the krytox at the piston and chamber that was brownish white. Reapplied Krytox and assembled the gun but it's still dieseling after 150 shots. I took out the breech seal and washed it with soap and cleaned the breech seal cutout. I'm out of ideas. Can grease get in the forks? Are the forks hollow? Is there anything better to degrease with than brake cleaner? Maybe I should soak the fork/breech/chamber in brake cleaner? I soaked it in simple green when I first started this whole vortek install. Any insight into the issue would be greatly appreciated, I'm kinda losing my mind here   

I should mention the dieseling varies from strong (thick smoke that prevents one from looking down the barrel, loud .22 rimfire like bang) to light dieseling (tiny bit of smoke in the barrel with barely noticeable recoil. Maybe I should try some citrus cleaner?

[KeepItClassy]

Bought a 95 a few months ago. Shot about 2500 pellets through it with only minor dieseling during the first 100 shots. Purchased a vortek kit and installed it using the grease they supplied in the kit. The rifle kept dieseling past 250 shots so I bought some krytox 205 and cleaned out the gun again with brake cleaner followed by multiple paper towels on a rod and finished off with some simple green. Rifle still dieseled after 100 shots. Took it apart again and cleaned out all the krytox at the piston and chamber that was brownish white. Reapplied Krytox and assembled the gun but it's still dieseling after 150 shots. I took out the breech seal and washed it with soap and cleaned the breech seal cutout. I'm out of ideas. Can grease get in the forks? Are the forks hollow? Is there anything better to degrease with than brake cleaner? Maybe I should soak the fork/breech/chamber in brake cleaner? I soaked it in simple green when I first started this whole vortek install. Any insight into the issue would be greatly appreciated, I'm kinda losing my mind here   

I should mention the dieseling varies from strong (thick smoke that prevents one from looking down the barrel, loud .22 rimfire like bang) to light dieseling (tiny bit of smoke in the barrel with barely noticeable recoil. Maybe I should try some citrus cleaner?

Shaker a little diesling wont kill you, just lightly lube the kit and reinstall, fire until the rifle the settles in and works off some of the extra lube.

Vortek kits are designed to dampen and smooth without having to load it up with grease or tar.

[Roadworthy]

I don't think it's your manner of cleaning so much as being too liberal with your lubricants.  If a little is good, less is better!!

Clean the gun again, paying special attention to the seal and cylinder.  When you lube the cylinder apply only a thin coat of whatever you're using.  Now wipe it off.  A residual film will stay and that's enough.  If you lube the seal at all keep the lube behind the lip.  If you have lubed the barrel at all, clean it with a water based cleaner and run patches until you're sure it's dry.

If you use a moly type lube be sure it's at least sixty percent moly.  Krytox works well, too.  Do not mix them or put one after the other without thorough cleaning.  That results in essentially no lube.  They are not compatible with each other.

Dieseling should stop within fifty shots.

[DanD]

Is it possible that your piston seal got nicked during assembly or disassembly? Deburring slots and holes in the receiver can minimize this, or if in a hurry you can use a strip of Tyvek envelope between the seal and chamber during install, or even just push the lip of the seal away from any edges it goes past with a small screwdriver.
Is it possible there is oil or cleaner left in the barrel or getting into the chamber from barrel cleaning.?
I wonder if Simple Green (or citrus cleaner) could leave a residue that is causing problems.
I use brake cleaner alone to clean the tube- it should strip out the grease without leaving anything behind. I personally do not lube the chamber at all because I don't want any lube to get pushed in front of the seal on assembly, and the chamber only needs lube where it contacts the piston. I just apply a thin smear of moly or krytox behind the lip of the piston seal, a thin smear around the middle of the piston, and a thin smear around the piston skirt, and some on the spring ends and thrust washers if the gun has them. I may also apply tar to the spring (but that's not needed on Vortek kit.) This lubing method, along with a seal in good condition, has worked well for me.

If a little is good, less is better!!

Sage advice right there^
Good luck. Let us know what you find.

[grauhanen]

Follow Roadworthy's good advice.

[nced]

Bought a 95 a few months ago. Shot about 2500 pellets through it with only minor dieseling during the first 100 shots. Purchased a vortek kit and installed it using the grease they supplied in the kit. The rifle kept dieseling past 250 shots so I bought some krytox 205 and cleaned out the gun again with brake cleaner followed by multiple paper towels on a rod and finished off with some simple green. Rifle still dieseled after 100 shots. Took it apart again and cleaned out all the krytox at the piston and chamber that was brownish white. Reapplied Krytox and assembled the gun but it's still dieseling after 150 shots. I took out the breech seal and washed it with soap and cleaned the breech seal cutout. I'm out of ideas. Can grease get in the forks? Are the forks hollow? Is there anything better to degrease with than brake cleaner? Maybe I should soak the fork/breech/chamber in brake cleaner? I soaked it in simple green when I first started this whole vortek install. Any insight into the issue would be greatly appreciated, I'm kinda losing my mind here   

I should mention the dieseling varies from strong (thick smoke that prevents one from looking down the barrel, loud .22 rimfire like bang) to light dieseling (tiny bit of smoke in the barrel with barely noticeable recoil. Maybe I should try some citrus cleaner?

I recently took delivery of a $299+shipping HW95 and was surprised that it had no dieseling from shot one but perhaps mine was unusual.

Anywhoo....I do have a few comments concerning dieseling after degreasing and relubing based on my .177 R9. The R9 is several years old with 10s of thousands of shots so there was no dieseling, however after stripping the receiver of molly paste and switching to Dupont Krytox GPL205 I noticed that I had a slight whiff of "strange smell" but no dieseling. After about 1500 shots I broke down the R9 for an inspection since I was using a new lube and was surprised to find "black" mixed with the white Krytox. This puzzled me so I took a pic of the insides of the R9 receiver and found that the braze was porous where the receiver fork was induction brazed to the receiver tube. Here's the pic showing the porous braze..........

It seemed that since Krytox doesn't mix with "petro based lubes" (like molly paste) I suspect that the Krytox leached out the molly paste that had been pressed into the voids with thousands of shots. Seems that stripping with brake cleaner didn't get the "deep down in the crevices" molly paste but the Krytox did leach it out. I relubed with Krytox, reassembled the R9 and took another 1500 shots and did another "look see". Guess what, there was no "black" mixed with the white lube but there was a bit of gray discoloration however the "strange whiff" was gone and the R9 has been performing well for a couple years since. I really don't know if your HW95 has the same issue as my R9 but if there is dieseling "petro lubes" in the nooks and crannies to be leached out and get pushed in front of the piston seal then the "petro lubes" mixed with the Krytox will diesel even if the Krytox doesn't.

Here is a pic of the insides of the HW95 receiver tube I recently bought...........

I also have a pic of several old R9 receivers from my parts bin............


As the pics show.....neither my newer HW95 or the older R9 receiver tubes show the porous braze of the R9.

My friend bought a new HW95 on sale after I bought mine and his didn't diesel either, however when I stripped his gun, added a home rolled tune kit, and relubed with Krytox I noticed that his piston seal seemed to fit surprisingly loose in his receiver. Since I replace my factory HW piston seals with home rolled oring sealed piston caps I had the practically unused HW piston seal in my parts bin so I placed it on his piston. Sure enough, the piston seal from my HW95 did fit his receiver a bit snugger so perhaps there might be enough a size variation to cause excess "petro lubes" to migrate past the piston. I really don't KNOW why excess "petro lubes" are migrating past your piston seal but that is the reason for your dieseling. Actually, I don't know how much of an issue minor dieseling would be other than affecting the consistency of velocity (I'm assuming that you aren't getting detonation).
A couple questions......
*Have you chronied a shot string to see how much velocity variation there is? I personally like "single digit" velocity spreads but depending on the pellet it could be more and still be accurate.
*More important than "velocity consistency" is the gun grouping well? LOL.....as long as the pellets land close together at 50 yards (for me about 1"ctc is close together enough when shooting from "bucket and sticks"), I really could care less what the velocity spread happens to be!

[ShakerT44]

I really don't KNOW why excess "petro lubes" are migrating past your piston seal but that is the reason for your dieseling. Actually, I don't know how much of an issue minor dieseling would be other than affecting the consistency of velocity (I'm assuming that you aren't getting detonation).

I don't have enough experience with air rifles to identify detonation or minor dieseling. Considering how every 1/15 shots fill the barrel half full of smoke, I suspect that might be detonation.

A couple questions......
*Have you chronied a shot string to see how much velocity variation there is? I personally like "single digit" velocity spreads but depending on the pellet it could be more and still be accurate.
*More important than "velocity consistency" is the gun grouping well? LOL.....as long as the pellets land close together at 50 yards (for me about 1"ctc is close together enough when shooting from "bucket and sticks"), I really could care less what the velocity spread happens to be!

I haven't pulled the chrony out yet, I won't have time till the weekend but I will report back with the results.  My main concern with the dieseling issue is disturbing the neighbors with what sometimes sounds like a .22 rimfire. For now I'm shooting in my garage. I will try to put 500 more pellets down the barrel before I take the rifle apart for inspection.

[robertr]

 What is the weight of the pellets you are using, if they are light pellets by putting in the Vortek kit you may have gained some fps over stock. The sound you hear could be the pellet breaking the sound barrier, try heavier pellets if that is the case.

[ShakerT44]

What is the weight of the pellets you are using, if they are light pellets by putting in the Vortek kit you may have gained some fps over stock. The sound you hear could be the pellet breaking the sound barrier, try heavier pellets if that is the case.

I didn't consider this. Been using crossman 14.3 grain .22 pellets. I will test something in the 18 range. Thx

[robertr]

 If your rifle is .22 cal it might not be the problem, I was thinking .177, I don't know if the HW 95 would shoot even the 14.3 's near the speed of sound but you can try anyways, won't hurt.
 

[nced]

I really don't KNOW why excess "petro lubes" are migrating past your piston seal but that is the reason for your dieseling. Actually, I don't know how much of an issue minor dieseling would be other than affecting the consistency of velocity (I'm assuming that you aren't getting detonation).

I don't have enough experience with air rifles to identify detonation or minor dieseling. Considering how every 1/15 shots fill the barrel half full of smoke, I suspect that might be detonation.

A couple questions......
*Have you chronied a shot string to see how much velocity variation there is? I personally like "single digit" velocity spreads but depending on the pellet it could be more and still be accurate.
*More important than "velocity consistency" is the gun grouping well? LOL.....as long as the pellets land close together at 50 yards (for me about 1"ctc is close together enough when shooting from "bucket and sticks"), I really could care less what the velocity spread happens to be!

I haven't pulled the chrony out yet, I won't have time till the weekend but I will report back with the results.  My main concern with the dieseling issue is disturbing the neighbors with what sometimes sounds like a .22 rimfire. For now I'm shooting in my garage. I will try to put 500 more pellets down the barrel before I take the rifle apart for inspection.

Detonation is an audible "bang" with elevated velocity. Dieseling is simply "smoke in the hole" and the Greyhound bus stop smell afterward. If you're talking a .22 cal HW95 it's highly unlikely that you're getting "sound barrier breaking velocities" unless you squirted oil directly through the transfer port. After mentioning this I remembered a little mishap I had when using molly paste to lube my .20 cal R9 piston and piston seal. I must have inadvertently squeegeed a wad of molly paste in front of the piston seal from the receiver after lubing. I took a shot over the chrony and there was a MIGHTY BANG which sent an 11.5 grain Beeman FTS pellet over the sensors at 1250fps.......plus that single detonation snapped the brand new aftermarket spring I had installed!!!

Since that time I used extreme caution when I used "petro based lubes" like molly paste to make sure there wasn't enough "fuel" to detonate. LOL....to eliminate the dieseling tendencies of my R9 I started using only dry graphite powder (the stuff you puff into locks) for piston and piston seal lubing. This did work well and I used the dry graphite for a couple years till I read about the non-dieseling properties of Krytox. I tried the Krytox and was satisfied that I had finally found a non-dieseling "one lube for all" in my HW springers! 

[Springrrrr]

If you use a moly type lube be sure it's at least sixty percent moly.  Krytox works well, too.  Do not mix them or put one after the other without thorough cleaning.  That results in essentially no lube.  They are not compatible with each other.

I know they are not compatible in that one is mineral based and the other synthetic, but to suggest it completely nullifies all lube properties is the part I don't understand.

They may not mix well but they are both fine lubricants.  Every lubricant or liquid that I have seen that are not compatible, separates eventually (like oil and water) but I don't understand what would kill off the lubricant properties of molly and Krytox?

[nced]

If you use a moly type lube be sure it's at least sixty percent moly.  Krytox works well, too.  Do not mix them or put one after the other without thorough cleaning.  That results in essentially no lube.  They are not compatible with each other.

I know they are not compatible in that one is mineral based and the other synthetic, but to suggest it completely nullifies all lube properties is the part I don't understand.

They may not mix well but they are both fine lubricants.  Every lubricant or liquid that I have seen that are not compatible, separates eventually (like oil and water) but I don't understand what would kill off the lubricant properties of molly and Krytox?

IMHO....what happens when mixing Krytox with petro based lubes (according to Dupont) for bearing lubrication is that the petro lube in the mix will fail with time contaminating the Krytox. Since piston guns aren't "high speed bearings", I seriously doubt that petro lube in the mix will cause issues other than the fact that the "dinosaur oil" will diesel and the Krytox won't, but the Krytox does seem to have the ability to leach dieseling "dinosaur lubes" from hidden nooks and crannies so it can diesel if pushed in front of the piston seal.

From this Dupont literature......
http://www.origin.dupont.com/Products_and_Services/en_AU/assets/downloads/dcse%20msds/krytox/H-96092,%20Krytox%20FG%20Application%20Guidance.pdf
"Preparing the Bearing or System
Because of the unique nature of the Krytox® mol-ecule, its performance is optimized when it is applied to a clean surface. Most bearings and equipment come with a preservative coating on them and bearings often have a lubricant already applied. These greases and preservatives should be removed before the Krytox® is applied. The preservatives and greases coat the metal surface to lubricate and prevent rusting, so they can also prevent the Krytox® grease from adhering—causing it to be thrown off by the action of the bearing. These hydrocarbon based materials also will oxidize and harden and can create debris that will contaminate the Krytox®. They can be removed using the standard solvents and hydrocarbon cleaners that you have always used. Do not use chlorinated solvents as they can cause corrosion to begin. Because you will be removing all rust preventive coatings, you should do this cleaning just before you plan on lubricating and installing the bearing or equipment. If you clean the parts and do not immediately relubricate them, you must keep them in a clean dry location to prevent rusting."

[ShakerT44]

Had a chance to shoot some assorted pellets through the Chrony. I didn't have enough heavier pellets to generate any meaningful results above 15gr. Here is the 10 shot string of .22 cal 14.66gr

H&N FTT 14.66gr Shot1 728.7 Shot2 718.0 Shot3 706.0 Shot4 725.0 Shot5 721.9 Shot6 722.5 Shot7 720.4 Shot8 722.7 Shot9 720.1 Shot10 719.8 It's still dieseling but I suppose it's not serious if the average spread is <10. Highest I got from 14gr was 740. I've had a few shots with almost no dieseling and I could really feel the benefits of the vortek kit. Hopefully after 500-1000 pellets the dieseling will stop and the recoil will calm down. If it doesn't stop, I guess I will just clean out out the piston and chamber again.

[Methuselah]

Had a chance to shoot some assorted pellets through the Chrony. I didn't have enough heavier pellets to generate any meaningful results above 15gr. Here is the 10 shot string of .22 cal 14.66gr

H&N FTT 14.66gr Shot1 728.7 Shot2 718.0 Shot3 706.0 Shot4 725.0 Shot5 721.9 Shot6 722.5 Shot7 720.4 Shot8 722.7 Shot9 720.1 Shot10 719.8 It's still dieseling but I suppose it's not serious if the average spread is <10. Highest I got from 14gr was 740. I've had a few shots with almost no dieseling and I could really feel the benefits of the vortek kit. Hopefully after 500-1000 pellets the dieseling will stop and the recoil will calm down. If it doesn't stop, I guess I will just clean out out the piston and chamber again.

Good numbers.

I had what I thought was smoke sometimes coming up the barrel, finally realized it was moisture, not smoke.  What I believe caused it was taking it from cold indoors to warm high humidity outside so the moisture in the air condensed in the cold barrel.  It would only happen every first couple shots...

All I know is I chrono'd it happening once (using chrono connect cellphone app), fps was not changing.

Your numbers indicate you don't have an issue.