Original Diana 35 - elastomer piston seal ? Better?

[ignacio49]

I am close to buy an original Diana model 35 and (maybe) an original model 50.

These rifles most probably will need new piston seals. There is a website in Germany that has many replacement parts (I do not know if I am allowed to write their address/link here...I am sure many of you know who they are).

They have the original seals, three parts, all (I believe) made of leather. They also have an elastomer piston seal, only one piece that replaces the three leather parts.

Should I buy the "modern" elastomer seal? Better than the originals -why?

Thanks
Ignacio

[air-tech]

I know of these seals and someone on here has actually tried them out, try a search using different terms maybe it will come up? IIRC it was for a 35, too.

Having said that whatever the outcome don't expect any major power or you may be disappointed. But perfectly usable guns.

[Benelli B76]

I am close to buy an original Diana model 35 and (maybe) an original model 50.

These rifles most probably will need new piston seals. There is a website in Germany that has many replacement parts (I do not know if I am allowed to write their address/link here...I am sure many of you know who they are).

They have the original seals, three parts, all (I believe) made of leather. They also have an elastomer piston seal, only one piece that replaces the three leather parts.

Should I buy the "modern" elastomer seal? Better than the originals -why?

Thanks
Ignacio

Polyurethane elastomer seals are by far the best. Having "memory" resilience they can take a pounding and keep their shape. I make my own on a lathe and seen old rifles improve after fitting replacements. Having a thin lip parachute design gives the best results. Most manufacturers today use polyurethane.

Baz

[PhatMan]

Ignacio,

My 1974 Diana (Original) 35 still has the original leather piston washer, and is still going strong

Perhaps you could 'save' the washer in the 35 & 50 you are buying ?

Have fun & a good Sunday

Best regards

Russ

[ignacio49]

Ignacio,

My 1974 Diana (Original) 35 still has the original leather piston washer, and is still going strong

Perhaps you could 'save' the washer in the 35 & 50 you are buying ?

Have fun & a good Sunday

Best regards

Russ

Russ, I also have an original 35, 1970, which I bought new and, as yours, still working fine. Seldon used, and seal kept wet, that's why I guess.

But the 35/50 I am considering have been treated careless as far as I can see (some oxide and dirt), and hence my suspicion that they may need a seal change. Hope they won't.

[ignacio49]

Somewhere I read that the modern seals are shorter, and the piston will/may hit the cocking arm and may cause serious damage.

Have you heard about this? Comments?

This is the "modern seal" I am looking at. It replaces the original three parts seal:

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

[ignacio49]

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

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

Thanks

[Jimny4x4]

Polyurethane elastomer seals are by far the best. Having "memory" resilience they can take a pounding and keep their shape. I make my own on a lathe and seen old rifles improve after fitting replacements. Having a thin lip parachute design gives the best results. Most manufacturers today use polyurethane.

Baz

Benelli B76 - Where do you buy the raw material ? Am interested .

[Benelli B76]

Benelli B76 - Where do you buy the raw material ? Am interested .

There are various diameter rods advertised on the evil bay. Just search polyurethane rod. Be careful some companies charge a lot more than others. May be best just to google it and find the original suppliers.

Baz

[jonnyone]

There are various diameter rods advertised on the evil bay. Just search polyurethane rod. Be careful some companies charge a lot more than others. May be best just to google it and find the original suppliers.

Baz

Is that the same as OEM seal materials or better Baz?
Do you think its possible to machine a seal to fit on Diana piston heads or would that have to be injection moulded due to the dovetail shape of the retaining stud? Or would it be better to dispense with that fitting arrangement and do a different design?
I'm
very interested in this aspect of air rifle improvement but I have neither.the knowledge, skill, or.equipment to pursue this myself
Dave

[Benelli B76]

Is that the same as OEM seal materials or better Baz?
Do you think its possible to machine a seal to fit on Diana piston heads or would that have to be injection moulded due to the dovetail shape of the retaining stud? Or would it be better to dispense with that fitting arrangement and do a different design?
I'm
very interested in this aspect of air rifle improvement but I have neither.the knowledge, skill, or.equipment to pursue this myself
Dave

Dave, the PU rod I buy works as good as factory supplied and is available in similar hardness as measured with a Durometer at 90 to 95 Shore A scale. I have made seals for the Original 6 M pistols with the dovetail taper fitting just by setting up cutting tools as required on my little Emco Compact 5 lathe. Making PU replacement seals for leather ones in old classic air rifles like the Bonehill Brittania and others sometimes gives up to a 100 fps increase in power. Obviously you have to get a good fit, neither too tight or too lose. Having a thin undercut lip on the edge of the seal helps it seal in the chamber bore under compression.

Baz