Hatsan Vortex air spring reseal

[mikeyb]

Recently purchased a refurb Mod125 Vortex. Summary here...
https://www.gatewaytoairguns.org/GTA/index.php?topic=213871.msg156528216#msg156528216

I ordered the parts I need to convert to a coil spring rifle. Hatsans response was fastest I've experienced from them and I was EAGER to work on the rifle when the parts arrived.

Parts ordered were Mod125 3-hole end-plug and Mod125/135 coil spring. I make the spring guide and washers myself. Those parts from Hatsan are very crude or undersized so it is EASY to make better parts with simple hand and power tools.

Sadly Hatsan sent Mod135 end-plugs. The 135 plug fits the 30mm ID tube where I really need the 125 end-plug that fits the 29mm ID tube. Hatsan discovered they don't have the 29mm plug so my conversion to coil spring is on-hold until they get the parts delivered (from Turkey?).

That could be many weeks so I decided to rebuild the leaky Vortex with the o-rings I ordered last year.

https://www.gatewaytoairguns.org/GTA/index.php?topic=204885.msg156421749#msg156421749

Removed the aluminum fill-port-end with minimal effort.

Pushed the "rod" out the open tube end/

The brass "gland" end that seals the rod was difficult as usual. Had to apply propane-torch-heat until smoke poured out of the cylinder. That softened the threadlocker compound enough for me to remove the brass end.

The really difficult part was removing the 2 old INTERNAL 8mm o-rings. I did NOT soak them in solvent as suggested, but will definately try that NEXT TIME I reseal a Vortex. My normal o-ring picks did not work on the HARD and BRITTLE o-rings. I needed to grind a custom curved flat-tip needle and scoop out the old o-rings in small chunks. WHAT A PAIN!

Cleaned ALL the threads. Removed ALL old o-rings. Installed all NEW o-rings. Smeared a little silicone grease on all threads and o-rings. Installed rod into brass gland, threaded brass gland onto pressure tube, then threaded on fill-port-end.

Started to HAND PUMP the Vortex back up to pressure. Target was 145 Bar listed on the Vortex as fill pressure for maximum muzzle velocity. Got to 80 Bar and the cheap probe extruded its end o-ring with a SNAP-HISS. I re-seated that o-ring and tried again. Got to 100 Bar and there was another SNAP-HISS! The fill probe extruded and split the OTHER o-ring. Probe is a cheap aftermarket version so no surprise they used low quality cheapest (too soft) o-rings. Both felt like 70A Buna so I replaced them with new 90A. NOW we're cookin'!

Hand pumped the Vortex right up to 145 Bar and reassembled rifle. Cocking effort seemed NORMAL. I likely overfilled it the last time around because that hand pump gauge is in MPa and I'm still learning to make the conversion. Muzzle velocity for the CPHP 7.9 grain averaged 1160fps. A little lower than expected but still a painful supersonic CRACK! Shot cycle was firm but smooth. ME is low but I need to test OTHER pellets over the next few weeks while watching & waiting to see if the new Vortex o-rings will hold air.

[Ronno6]

Sounds like my experiences removing old, brittle O-rings.
What solvent soak will ease this pain?
thanks..........

[Mossonarock]

Mikey,

Are you saying Hatsan sent you a 135 end plug that's meant for using a coil spring?

[mikeyb]

Sounds like my experiences removing old, brittle O-rings.
What solvent soak will ease this pain?
thanks..........

Uncertain, but I have some acetone which "I think" will be pretty harsh on the old o-rings.

[mikeyb]

Mikey,

Are you saying Hatsan sent you a 135 end plug that's meant for using a coil spring?

Yes. I ordered 3 coil springs and 3 three-hole-endplugs for the Mod125 (29mm).

They sent the 30mm three-hole-endplugs for Mod135 instead.

Both rifles use the same coil spring.

I'm keeping the error plugs because I HAVE Mod135 and 130 Vortex rifles and when those eventually leak I can convert to coil spring. My current need was only the Mod125 rifles but luck was not on my side that day :-)

[Ronno6]

Sounds like my experiences removing old, brittle O-rings.
What solvent soak will ease this pain?
thanks..........

Uncertain, but I have some acetone which "I think" will be pretty harsh on the old o-rings.

I have read brake fluid.....but dunno if anything will soak into the brittle little critters.....

[mikeyb]

Seems like we both have possible solutions? :-)

Buna o-rings should not be used to seal against brake fluids or acetones, as its resistance to these chemical compounds is not strong to handle long-term exposure.

from

https://www.applerubber.com/blog/everything-you-need-to-know-about-buna-o-rings/

[Ronno6]

3 hours in acetone REALLY helps!

Easiest O-ring extraction I have ever done.....

[dw]

Just tackled replacement of the o rings in the Vortex spring from my 135 that failed earlier this year. I read somewhere to use a dental pick to remove the old brittle o rings from the end of the spring, and that was exactly what I needed! Wasn't too difficult with that tool.

Not sure I'm going to reassemble everything yet, since I have a brand new spare already and I don't want to have this refurbished piston leak down over the next few years...

[Ronno6]

Well done !
Make sure to add 6 drops of silicone oil in the tube before re-assembling......

I have found that soaking the O-ring gland in acetone for a few hours really makes their removal easier.....

[James340]

Curious.Has anyone tried lower pressure in the Vortex?I was thinking of lowering the pressure in a Model 25 Super Changer.I put 1500 psi when I resealed it but I don't really need that much velocity.

[mikeyb]

Curious.Has anyone tried lower pressure in the Vortex?I was thinking of lowering the pressure in a Model 25 Super Changer.I put 1500 psi when I resealed it but I don't really need that much velocity.

Lowering the Vortex pressure, like cutting a coil or two from a coil spring, to get a rifle shooting "better" is a solid idea! Only problem is that Hatsan started making Vortex air springs WITHOUT bleed ports. There is no easy/simple way to let air OUT!

Oh wait... maybe that is why I"ve had so many leak? Hatsan built in a leaky o-ring feature so no bleed screw is needed (SARCASM).

If your Vortex has a bleed screw you can easily experiment with different pressures to get whatever ( within reasonable limits) muzzle energy is best for you :-)

[James340]

Curious.Has anyone tried lower pressure in the Vortex?I was thinking of lowering the pressure in a Model 25 Super Changer.I put 1500 psi when I resealed it but I don't really need that much velocity.

Lowering the Vortex pressure, like cutting a coil or two from a coil spring, to get a rifle shooting "better" is a solid idea! Only problem is that Hatsan started making Vortex air springs WITHOUT bleed ports. There is no easy/simple way to let air OUT!

Oh wait... maybe that is why I"ve had so many leak? Hatsan built in a leaky o-ring feature so no bleed screw is needed (SARCASM).

If your Vortex has a bleed screw you can easily experiment with different pressures to get whatever ( within reasonable limits) muzzle energy is best for you :-)

I just finished testing.I went from 1000 psi up to 1400 ish.1500 psi is stated max pressure for the type 3 vortex ram.I should have stopped at 1350 ish @475 fps with RWS Super Dome 177 cal.1400 psi is 507 fps but not nearly as smooth to cock.

[mikeyb]

Recently purchased a refurb Mod125 Vortex. Summary here...
https://www.gatewaytoairguns.org/GTA/index.php?topic=213871.msg156528216#msg156528216

I ordered the parts I need to convert to a coil spring rifle. Hatsans response was fastest I've experienced from them and I was EAGER to work on the rifle when the parts arrived.

Parts ordered were Mod125 3-hole end-plug and Mod125/135 coil spring. I make the spring guide and washers myself. Those parts from Hatsan are very crude or undersized so it is EASY to make better parts with simple hand and power tools.

Sadly Hatsan sent Mod135 end-plugs. The 135 plug fits the 30mm ID tube where I really need the 125 end-plug that fits the 29mm ID tube. Hatsan discovered they don't have the 29mm plug so my conversion to coil spring is on-hold until they get the parts delivered (from Turkey?).

That could be many weeks so I decided to rebuild the leaky Vortex with the o-rings I ordered last year.

https://www.gatewaytoairguns.org/GTA/index.php?topic=204885.msg156421749#msg156421749
...

UPDATE:

HatsanUSA service/parts did make an error in my previous parts order (sent 30mm Mod135 end-plugs instead of 29mm Mod125 end-plugs) but honestly the parts are VERY similar and one needs calipers to measure the 1mm difference. Hindsight is always 20/20 but if I were on the original Hatsan Engineering team I would have specified etching (or inserts) part and revision numbers/letters into the injection molded tooling for my plastic parts. That's EXACTLY what we did for my almost 20 years designing electronic security devices using molded housings and optics. All molded parts, except the smallest optical light-pipes, had a part number and revision letter for identification.

Back to topic... I received an email this week from HatsanUSA service associate Kadden that the Mod125 parts I originally wanted were now back in stock and asking if I still wanted them. I DID!  I also requested, if they had stock, more of the Mod125/Mod135 coil springs. Yes! They promptly sent me an invoice for the parts. Invoice paid and now parts are in transit.

While NOT PERFECT I'm still pleased with the response from HatsanUSA service and parts.

A shoutout ThankYou to Kadden at HatsanUSA service for remembering to contact me when the parts I wanted were restocked :-)

[mikeyb]

More updates:

The new o-rings in the Vortex are likely OK but that Vortex was WAY low on pressure AGAIN (doh!)
CPHP were looping out at 400fps so here I go again :-(
I REALLY DID crank on that bleed port screw but I think the bleed port needs a new sealing washer.

Regardless, I just received my Mod125 coil spring conversion parts from HatsanUSA and decided to convert the rifle to a coil spring.

Pulled the Vortex air spring and the matching 2-hole end plug.
Installed a Vortek 142 coil spring fitted to one of my 7" pipe spring guides. Added the 29mm 3-hole end plug and SQUEEZED everything together in my spring compressor.

I have the Hatsan factory coil springs but wanted to see how the Vortek coil spring performed.
I ordered some Vortek springs awhile back when Hatsan was out-of-stock. Got the full length open ended 0.142" wire x 0.840" OD springs so I could close the ends and grind them flat myself.

Vortek free length ~1.5" shorter than Hatsan OEM coil spring.
Was expecting maybe lower ME from that difference but now think Vortek spring may be "SET" while Hastan spring is "NOT SET"??

Vortek spring may also be better steel? Cost of Vortek coil spring ~$30 while Hatsan coil spring is ~$20.
https://vortekproducts.com/products/142-wire-840-od-spring

10.5 grain Piranahs shooting ~34 fpe at 30' = WOW!

Target grouping photo:
Aimed at upper sharpie ring = circled LOW pellet hole was initial shot before sight adjust.
Raised rear sight several clicks then shot 20 more at upper sharpie-ring.
Data for 20 shots in table.


Mod125 Vortex (now coil spring) refurb 177 black, date code 0614. This rifle is about 10 years old if manufactured in June 2014.
With results like this I am DONE with Vortex air springs.

[mikeyb]

More updates:

...

10.5 grain Piranahs shooting ~34 fpe at 30' = WOW!

...

WRONG!

Oops, made a stupid cell-reference error and didn't double-check my work.

NOT shooting at 34ft-lbs. ACTUALLY shooting at 25ft-lbs. Should have realized those numbers were too good to be true :-(
Wishful thinking.

Still happy with coil spring performance and no longer needing to worry about a limp Vortex next time I have an emergency pest dispatch.

Sorry anyone following :-)

[dw]

Man, I should have re-read this thread before I redid the o-rings on another failed type 2 vortex piston! Those brittle old 0-rings were a mean woman to remove. I'll need to try an acetone soak for a few hours for the next time.

Putting the new o-rings into the brass part was a little tricky, but I found just putting one bit of the o-ring into the cutout and shoving the plunger in from the other direction really helped.