RedFeather (no login) from IP address 72.83.243.103
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Been reading about tarring springs and was wondering. I've got a small tub of Valvoline wheel bearing grease. Would that work on a spring? Says it's #2 BLG (lithium based). I've an old Diana 50 that twangs like Tweety banging a pot over Sylvester's head. As its at least fifty years old and has had nothing done to it, figure the spring could use a little lube. Ditto a new Gamo S1000 that could stand to be a bit more docile. I know I could order something from JM, but I've got this on the workbench.
Dear Sir, reading your story it seems to me that the piston seal ( perhaps a leather one when i read the age of the rifle ) is worn out so you have to replace this important part of your action. Use the genuine Diana seal ( blue one is the best ) and use very little grease. It's simple: clean the chamber serious and only a very, very small film of grease is allowed on the wall of the chamber, also very little grease on the seal ! The automotive grease is actually not the best, perhaps you know someone who has a few fingertips Molykote 44 for you ? Succes in your air rifle rebuild and keep the older Diana's alive ! Best regards from Johannis.
NLGI 2 is on the thin side, especially when compared to so-called 'tar'. The stuff that truckers put on fifth wheels 'looks' right - thick, black and nasty - but no experience with it other than drive-bys.
I curently use the JM Euro Lube for mainsprings in my guns, it is not like the tars, it is a silicon grease and it seems to make the spring nice and slippery when you use it, does not really dampen vibration down or anything like that. Regular wheel bearing grease would work, however it could be petroleum based and if it got into the compression chamber would diesel. Now on a older gun like the 50 with a leather seal it might not be as crucial, a newer gun with synthetic seals magnum springer if it got in the compression chamber might not be so good. If you want to use something available on hand you might just look for a silicon based grease around the hardware stores or automotive supply places, I have really like the euro lube as it is probably very similar to what the factories use on guns.
I guess it would be best to just order up some tar and such from JM. As to the Diana 50, it's about a late 1950's model E. I've let the seal soak in some pure silicon administered through the tap. Maybe I will add a few drops more. I understand that the leather sealed series require a good bit of work to replace as they are staked on. When the time comes to tear it down, I may just fashion a new leather seal to keep it original. They weren't power houses to begin with. But, man, does it ever clank when I shoot it! A little tar may go a long ways to tone it down.
I won't respond about the seal on your old gun as I have no experience.
In a springer, you don't won't any petroleum products in the chamber. If you did your gun would "diesel" because the heat from the compression of the air would ignite it, just like a diesel engine. This can and has caused guns to blow up and injure people. So never ever put flammable stuff in the combustion chamber. I wouldn't even use silicone oil.
On the spring, the idea is that you want a really tacky grease so that when the trigger is squeezed and the spring moves (uncompresses) the lube doesn't going flying off the spring. Instead of wheel bearing grease think more like pine tar/pitch.
In the compression area, the area in front of the seal, you want to de-grease and cross hatch hone first. Then an easy to find lube is the silicone grease used on spark plug boots (JM's moly grease is fine here too). Just put a thin film around the sides of the seal (if the gun squeals as you cock it after a couple of dozen rounds use a little more). Behind the seal, on the metal piston, get some 65% moly from Honda and put a light smear on the metal piston. Light means light and most use way too much. The spring is the only place you use much.
Now what is supposed to happen, and some will argue, is that each time you shoot the gun the spring will throw off a small amount of grease. Heat will cause it to migrate down to the seal area and the cross hatch honing will allow a very small amount to leak past the seal. This is what allows a high power springer to reach the power levels it does. It is a form of controlled dieseling.
Like I said, these old 50's/27's/35's are pre-"magnum" rifles. I wouldn't want to try to boost the speed. Have other, faster airguns if I need that. On the leather seal, I was told to use pure silicon oil. FWIF, we used silicone oil in some thousand pounds per square inch systems on my old sub, mainly due to its resistance to dieseling or ingniting under extreme pressures. Anyway, you have to put something on the leather to rejuvinate it and keep it supple. Thanks for all the rebuild info for when the day comes I have to tear it down. (I'm NOT messing with that three ball trigger, though! )
Russ, you gave the best explanation of what happens when "lubricating" an air rifle what is absolutely not done ! However the production tolerance is within 1/10 from millimeters and a VERY LITTLE grease is always needed to avoid loss of pressure during the energy stroke. In your country there are some very good products available like Molykote 44, Molykote 3451 etc. And of course use the genuine Diana seal. ( best one is the blue one ) best regards from Johannis.
I have never tried aftermarket seals yet, the blue Diana seals are now improved over the older seals that were used in airguns in the past. Basically the only other seal you could use is a aftermakert of some type as I noticed JM sells Apex seals and who knows there may be other brands around, the only thing today I could see is a aftermarket seal not being held to tolerances and not being as good, there is no reason not to use a genuine Diana seal unless you have a gun that the seal is out of production for.
The only original Diana seal for the model 50 is leather.
The seal is retained by a central screw.
The seal kit (part #301256) is sold as a package containing the leather cup seal, a fibre backing washer, a centre washer and the retaining screw.
The kit is available from Diana distributors, Chambers, Schneider (www.luftdruckwaffen-shopping.de) and other parts suppliers.
The piston head is drilled from the side and a pin (part #300292) driven in to stake the retaining screw.
There is nothing to be gained by trying to substitute an aftermarket plastic piston seal into a max 9 ft-lb Diana 50.
When I work on the piston seals of 30+ year old Diana 25, 27, 35 and 50 series rifles, I do the following.
-I assume that the gun was improperly lubricated, neglected and abused.
-I soak and blot the seal still attached to the piston to remove all old previous lubricants
-I note that most of the dust sucked into the action over the years by cocking and firing is usually stuck in the seal and is polishing/scratching the cylinder.
-I only use paint thinner, brake cleaner or benzene (lighter fluid)to blot. MEK and lacquer thinner (acetone and toluene) may too harsh for the fibre washers.
-I use fine tweezers to remove the bits of pellets, straight pins, finishing nails, matchsticks and other debris from previous owners' misadventures.
-When it has dried I soak the seal in Dri-Slide which is Molydisuphide and Graphite powders along with some ZDP in a volatile carrier. The moly and graphite are of course lubricants and the ZDP is the detergent in motor oil that neutalizes acids generated by oxidation.
-Once the seal has dried overnight, I soak it with pure medium weight silicone oil
-I purchased a lifetime supply of ARH silicone oil when Air Rifle Headquarters shut down in 1981-82.
Assume that 50% of advice provided on internet forums is probably wrong.
I will copy this into Word. Probably disremembered what the poster said about the staking. Those guns go back quite a ways so maybe he was talking about fifty/sixty year old guns. I just used the silicon oil. Have to do some work on my 50, anyway, so I may opt for the replacement kit. The gun is in pretty nice shape for its age but someone tried to add a homemade brass scope rail to the receiver and looks like it was soldered in place. Pretty crude, too. Since I will have to heat it for removal, all the guts will need to be pulled out. Good time to check the spring, et cetera, and lube it. Any idea what replacement springs work (in case it's broken)? This is the .22 50E (for export?) and a circa late fifties model.
Dear Sir, nice to see your way of working however there are always different ways, methods and parts. There is a ( blue ) seal available for the 50 and why not use the modern materials ? I guess all info and support given via a forum is good and those who are the Diana collectors / owners / dealers can filter the right info ! You're right that ...% of the info is not correct, for example the kit no. is 301255 and not 301256 ! If you need something you can't get in the USA from Umarex or something "particular Diana" I am always willing to help, beste regards from Johannis. ( the Netherlands )
I don't mind the seal being leather. In fact, I've seen where guys cut their own from a piece of leather. While I know the newer materials are superior, on an old gun like this it would feel like putting a set of radials on a Model A Ford, if you get my drift.
I hope Umarex is a good supplier. In talking to them about a sight for my 75, I did not get a sense that they are into older parts. My best results were with RWS service when they were in New Jersey. Those guys were so knowledgable and knew the guns inside and out.
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