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Lubing the internal components of a spring-piston airgun

Posted: Thu Mar 08, 2007 1:11 pm
by Mack The Knife
1) Do NOT use Acetone/nail polish remover to degrease the inside wall of the compression cylinder. Use a solvent that evaporates and leaves no residue.

I use surgical spirit for this purpose which is available from any chemist. However, the commercially available surgical spirit leaves behind a trace of water, so it must be dried with a clean and dry cloth.

2) Do NOT lube/oil the inside of the cylinder wall.

3) Lube main-spring with constant velocity axle grease or motorcycle chain grease. Basically something that adheres to the spring and does not get flung off each time the spring is released. Do not overdo the grease. A nice even coat is what you want.

Some people put extra grease to get rid of the buzz/twang that a spring creates on being released. However, this will lower the velocity. The correct way to get rid of spring twang is to make a rear spring guide that is a nice snug fit rather than loose.

4) Lube the inside and outside of the rear spring guide with moly grease. Do not overdo it but not sparingly either. Ditto for the Top-Hat or front spring guide.

5) Lube the inside of piston or piston sleeve (if you have one or decide to make one) with moly grease. Once again, nothing in excess but not sparingly either.

6) Lube the outside of the piston sparingly.

7) There should be absolutely no lube of any sort on the face of the piston washer. Put a thin coat of moly grease along the side of the piston washer, then use a clean lint free cloth or tissue to wipe of the excess. This will leave a very thin film on the side of the piston washer and that is all that is required.

Note: It is assumed here that the piston washer is not made of leather.

Mack The Knife

Posted: Thu Mar 08, 2007 2:00 pm
by eljefe
Thanks Mack The Knife
Moly grease ready, dry teflon spray that you used is also there besides Ed's Red

Posted: Thu Mar 08, 2007 2:41 pm
by mundaire
Thanks for posting this Mack The Knife... It sure clarifies a few things.

About no lube in the cylinder... I read somewhere that a coating of teflon is good... what say?

Cheers!
Abhijeet

Re: Lubing the internal components of a spring-piston airgun

Posted: Thu Mar 08, 2007 3:12 pm
by Mack The Knife
You're welcome guys.

Never tried teflon spray for the internal cylinder wall but I think it should work.

Use a light coat and only try it on one air-rifle first. If it does not diesel heavily take that as a green signal. If it does diesel heavily (unusually loud muzzle crack and lots of smoke) stop immediately. Take it for granted that the piston washer has been scorched and replace it with a fresh one. If you ignore this, you will end up with a broken main-spring within the next few shots as well.

At what temperature and pressure would teflon detonate/combust?

Mack The Knife

Posted: Thu Mar 08, 2007 3:17 pm
by mundaire
Mack The Knife Bana";p="14112 wrote:At what temperature and pressure would teflon detonate/combust?

Mack The Knife
They use it as an after-market additive to engine oils in internal combustion engines... It is supposed to form a semi-permanent coating on the engine cylinder walls to reduce friction, so should be very stable. The only red flag that I know of is the "carrier" solvents that are used with it can be potentially combustible. I guess a dry spray such as the one Asif has, should not be a problem... But sound advice about trying it on one as a test first!

Cheers!
Abhijeet

Posted: Thu Mar 08, 2007 3:36 pm
by badshah0522
What About WD40??Is it recommended?
mundaire";p="14114 wrote:
Mack The Knife Bana";p="14112 wrote:At what temperature and pressure would teflon detonate/combust?

Mack The Knife
They use it as an after-market additive to engine oils in internal combustion engines... It is supposed to form a semi-permanent coating on the engine cylinder walls to reduce friction, so should be very stable. The only red flag that I know of is the "carrier" solvents that are used with it can be potentially combustible. I guess a dry spray such as the one Asif has, should not be a problem... But sound advice about trying it on one as a test first!

Cheers!
Abhijeet

Posted: Thu Mar 08, 2007 4:28 pm
by Mack The Knife
badshah0522";p="14120 wrote:What About WD40??Is it recommended
ABSOLUTELY NOT!

Posted: Thu Mar 08, 2007 6:03 pm
by badshah0522
Mack The Knife Bhai any specific reason for it???
Mack The Knife Bana";p="14124 wrote:
badshah0522";p="14120 wrote:What About WD40??Is it recommended
ABSOLUTELY NOT!

Re: Lubing the internal components of a spring-piston airgun

Posted: Thu Mar 08, 2007 6:07 pm
by Pran
Mack The Knife,
Great post.Very informative.Have a few doubts though.
What's moly grease? Remember an earlier post where you spoke of single handedly putting the spring back(using C clamps I think)Would appreciate it if you could explain the same with pics.

Pran

Posted: Thu Mar 08, 2007 6:15 pm
by Ranjeet Singh
badshah0522";p="14130 wrote:Mack The Knife Bhai any specific reason for it???
It Deisels I guess, While I had used vaseline to protect my airguns on the exterior, it would be disastrous to use it for internal componets lubing

Ranjeet

Posted: Thu Mar 08, 2007 6:20 pm
by mundaire
WD40 also leaves behind a gummy residue... which can't be very good for the health of your air-gun! I assume this along with the potential to diesel would be the reason...

Cheers!
Abhijeet

Posted: Thu Mar 08, 2007 7:25 pm
by Mack The Knife
Badshah,

WD40 is a petroleum based product and will cause massive dieselling - enough to break your main-spring and scorch the piston washer with the first shot.

Incidentally, WD40 is a water displacer and rust remover/loosener and should not be used as a lubricant.

Mack The Knife

Re: Lubing the internal components of a spring-piston airgun

Posted: Thu Mar 08, 2007 7:32 pm
by Mack The Knife
Pran,

Moly grease is short for Molybdenum Disulphide grease.

I don't think I have pics of my spring installing set up. If I do, I will post them. Failing which, they will have to wait until I instal the spring in Ranjeet's HW97K.

Mack The Knife

Re: Lubing the internal components of a spring-piston airgun

Posted: Thu Mar 08, 2007 7:42 pm
by Pran
Mack The Knife,
Where in Bangalore could I pick up moly grease?

>they will have to wait until I instal the spring in Ranjeet's HW97K

Take your time.Wouldn't mind watching it live either :)

Pran

Posted: Thu Mar 08, 2007 8:17 pm
by Mack The Knife
Pran,

Try the two hardware shops on Commercial Street failing which City Market.

I haven't bought locally as I am still using the pot of grease bought in '95 from Venom.

You'd be most welcome. I will call you once Ranjeet and I fix on a date and time.

Mack The Knife