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Airguns by Make and Model => Feinwerkbau => Topic started by: Joe58 on April 06, 2017, 06:57:33 AM

Title: FWB 300s Piston Seal Lubrication needed?
Post by: Joe58 on April 06, 2017, 06:57:33 AM
Hi!

Please forgive my lack of knowledge for my question.

On my 300s, the piston seal, is drying out and starting to barely crack. It's one of the old white ones so I'm assuming it is likely the original.

I have a new one on order. From what I've read, I can just dig out the old one and snap the new one in place, correct? Being sure I've all the bits and pieces from the old one removed of course.

Now, I want to verify I'm using the correct term here. The piston seal is the one that seals over the pellet as you close the breech with the cocking arm, right?

And, should I be lightly lubricating the seal for a better seal over the pellet and if so, what kind? The FWB special grease, or just a light coating of pell gun oil? Or do I run it dry?

Thanks! Joe
Title: Re: FWB 300s Piston Seal Lubrication needed?
Post by: Back_Roads on April 06, 2017, 08:57:31 AM
Actually that is referred to as the breach seal. I prefer to use silicone oil , 30 weight r/c car shock oil.
Title: Re: FWB 300s Piston Seal Lubrication needed?
Post by: JoeRhea on April 06, 2017, 09:43:52 AM
 The 300 rifles are designed to run almost completely dry. The dot at the end of this sentence is the amount of lube inside my guns . I normally just spray it down with light silicone spray lube , and use paper towels to wipe it as dry as possible ...Upside to to running them dry is more speed , and mainly more consistency!!! With no POI shifts . I use only or a light grease on spring ends and pivot arm . If you hit a snag give me a shout . 903-279-1326 and hopefully I can help....Ive made I think every mistake possible so maybe I can help you from following in my clumsy azz steps ;) .
Title: Re: FWB 300s Piston Seal Lubrication needed?
Post by: Jason_Garvin on April 06, 2017, 01:30:02 PM
Hi!

Please forgive my lack of knowledge for my question.

On my 300s, the piston seal, is drying out and starting to barely crack. It's one of the old white ones so I'm assuming it is likely the original.

I have a new one on order. From what I've read, I can just dig out the old one and snap the new one in place, correct? Being sure I've all the bits and pieces from the old one removed of course.

Now, I want to verify I'm using the correct term here. The piston seal is the one that seals over the pellet as you close the breech with the cocking arm, right?

And, should I be lightly lubricating the seal for a better seal over the pellet and if so, what kind? The FWB special grease, or just a light coating of pell gun oil? Or do I run it dry?

Thanks! Joe

Joe above has spoken wisely he has been in a couple before  ;)

The breech seal is what you see when the rifle is charged and the compression tube is to the rear.  You can pick it out and push another in.  I like to lightly coat with super lube then seat the breech seal.  You can push the seal in and slowly close the action and it will seat.  While the rifle is charge, you can look the through the air transfer port and see the piston bumper, it will fall apart in time.  The metal piston seal is snapped on the piston and you cannot see it unless the rifle is tore down in pieces.  I clean the loading port area with Ballistol, barrel, and use a q-tip with Ballistol to clean the lead off the breech seal after shooting.  You can paint a small amount of Super Lube, or ARH Clear Tar, into the receiver while the rifle is charged and Compression tube is to the rear.  This will work its way under and help the comp tube slide back and forth easier.

Good luck,

Jason G
Title: Re: FWB 300s Piston Seal Lubrication needed?
Post by: Joe58 on April 06, 2017, 06:45:45 PM
Yeah, I'm following you guys now. Wasn't using the right terminology. Which isn't surprising. :)

I was just looking at it, and the breach seal has flaked/cracked off all the way around. I believe mine dates from the 70's and I'm pretty sure it's likely all still original seals and whatnot inside. I'm sure it could use more than just a new breach seal. Although it is still shooting quite accurately.

I think the best idea would be for me to send it off for a rebuild, which will likely last me long enough till my wife puts me in the vets home. Lol.

Jim Edmondson says he'll rebuild it for me and oddly enough, if I'm remembering right, it was he whom I bought it from to begin with quite a few years back now. So I figure it'll come back and shoot like new. I just really like those old FWB's and the like.
Title: Re: FWB 300s Piston Seal Lubrication needed?
Post by: Jason_Garvin on April 06, 2017, 07:19:28 PM
Don't rule out David Slade at Airgunwerks he is one of the masters on those and has the training to back it up.  He did a couple for me back when.  I like to roll my own now, alot of how to guides out there.

Jason