Original Diana 35 - elastomer piston seal ? Better?

[ignacio49]

http://www.waffencenter-gotha.de/sho...a57a5be3272786

Anybody here that has installed this seal, and could confirm if working fine or not?

Thanks

[jonnyone]

http://www.waffencenter-gotha.de/sho...a57a5be3272786

Anybody here that has installed this seal, and could confirm if working fine or not?

Thanks

Really sorry I cant help mate as all conversions over to synthetic I have had done over the years has been to ptfe. Whilst I haven't had a moments trouble.I would suggest that the seal you show here would be equal if not superior to ptfe by virtue.of it being an.OEM part. Diana seals are.particularly good as far as factory ones go and I don't think you will go wrong with one..Plus from what I can see of things if the worst happens and performance goes backwards you have the option with this one to revert back to leather. I suspect you won't need to though. I think modern synthetic seals are superior to leather and keeping leather is good for originality but not if more consistent and higher power are the goal.
Dave

[ignacio49]

[QUOTE=jonnyone;7290152....all conversions over to synthetic I have had done over the years has been to ptfe. Whilst I haven't had a moments trouble........
Dave[/QUOTE]

Thanks Dave.

Probably you converted a Diana 35 or 50. If so, do you remember if the ptfe seals you used were shorter than the originals?

I ask because the seal I am looking at is shorter, and I was told this will cause trouble.

Ignacio

[jonnyone]

Thanks Dave.

Probably you converted a Diana 35 or 50. If so, do you remember if the ptfe seals you used were shorter than the originals?

I ask because the seal I am looking at is shorter, and I was told this will cause trouble.

Ignacio

Morning ignacio. I have fitted ptfe seals to two Diana 45s, one 50, one 50T01, two anschutz 335s, one HW35, and a BSF as I recall.
I have been fortunate in that despite the seals being thinner height wise than the original leather seal they have still had clearance between the cocking lever rod and the piston body. This can easily be checked after the seal is fitted. A few millimetres clearance is needed when the piston is fully pushed home against the end of the compression tube. Should this not prove to be the case then the new head will need.packing between it and the piston body to create that required gap. I recall some have used large tap washers in the past but as I say it has proved unnecessary for me. I can't say it will be the same for your gun as I have no experience of working on a 35.
Perhaps an email query to the seller of the synthetic seal may throw some light on things but even then I would still check the clearance as per the above after fitting?
Wish you luck
Dave

[Benelli B76]

PTFE is a poor material for piston seals as it is malleable and can be squashed out of shape. Polyurethane elastomer is a far better material and the most commonly used today.

Baz

[jonnyone]

PTFE is a poor material for piston seals as it is malleable and can be squashed out of shape. Polyurethane elastomer is a far better material and the most commonly used today.

Baz

Someone had best explain the ptfe failings to my guns. I fitted the first seal to an RWS 45 in the late 80s and its worked perfectly since (as they have all done). I think it's about time they started playing up a bit
Dave

[Drew451]

You should really have a word with those 50's while you're at it. They don't always realise tap loaders are meant to be old crap...

[Benelli B76]

Someone had best explain the ptfe failings to my guns. I fitted the first seal to an RWS 45 in the late 80s and its worked perfectly since (as they have all done). I think it's about time they started playing up a bit
Dave

PTFE does not need explaining to the guns but to people. PTFE can be cut with a knife. It is usually white in colour and is malleable that is why it is used for flange seals etc because it adapts to shape. A lot of people look at a synthetic seal in an air rifle and call it PTFE when it is actually polyurethane because they do not know about polymers. You can use it for piston seals but it will not give a good seal eventually, that is why airgun manufacturers do not use it. I repair airguns every day and never see it except on old Webley pistols, and it is used on the capsule seal for the Tanfoglio Witness pistol which is why they need to be changed after squashing out of shape.

Baz

[ignacio49]

Morning ignacio. I have fitted ptfe seals to two Diana 45s, one 50, one 50T01, two anschutz 335s, one HW35, and a BSF as I recall.
I have been fortunate in that despite the seals being thinner height wise than the original leather seal they have still had clearance between the cocking lever rod and the piston body. This can easily be checked after the seal is fitted. A few millimetres clearance is needed when the piston is fully pushed home against the end of the compression tube. Should this not prove to be the case then the new head will need.packing between it and the piston body to create that required gap. I recall some have used large tap washers in the past but as I say it has proved unnecessary for me. I can't say it will be the same for your gun as I have no experience of working on a 35.
Perhaps an email query to the seller of the synthetic seal may throw some light on things but even then I would still check the clearance as per the above after fitting?
Wish you luck
Dave

Great help Dave, thanks.