GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => German AirGun Gate => Topic started by: tjk on April 12, 2021, 12:19:39 PM
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Decided to tune my 35 and found some slight galling on the piston skirt. Same print on the comp tube. Not enough to cause a huge concern,...definitely a fixable issue , but enough to warrant either a buttoning or a bearing insert. I did notice a bit of free play with the skirt and the id of the tube. Any thoughts or theories on your preferred method(s)? This is why I usually tune my springers shortly after i buy them. But I wanted to give this rifle a wearing in and I could tell this issue was apparent from time to time after long shooting sessions. Starts smooth then gradually got a tad metal to metal wearing. Not coarse or crunchy,...just not smooth as it should be.
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The piston fit is always pretty sloppy. At least in Weihrauchs I've taken apart. Slight galling on the top of piston skirt is very common. Sometimes the roof of the compression tube. It's where the cocking force is directed. I just polish out the high spots with fine wet dry and green scotchbrite. As long as the galling in the compression tube doesn't extend into sealing area there's no need to worry.
You can add buttons or a bearing around the skirt, but to do it right requires a good machinist. Sure there's glued on buttons but I would not trust them. Plus buttons as a whole focuses the load on a smaller area than the original problem area. I personally don't think the juice is worth the squeeze. Particularly with buttons.
I've polished up whatever minimal piston galling there was on all my guns and they are all doing just fine. I have tens of thousands of rounds through my Hw30s and over ten thousand rounds on my Hw95 and the internal galling never grown since the initial polishing. They all cock smooth as melted butter and have received compliments from other shooters at the air gun range.
It's up to you. If you want to bearing the piston and you have the skills to, go ahead. I'm just saying it's unnecessary.
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We need a "Like" button! Thanks for your insight
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The buttons always seem to fall off. The bearings, while a great idea, need a lathe and a serious head stock.
-y
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Decided to tune my 35 and found some slight galling on the piston skirt. Same print on the comp tube. Not enough to cause a huge concern,...definitely a fixable issue , but enough to warrant either a buttoning or a bearing insert. I did notice a bit of free play with the skirt and the id of the tube. Any thoughts or theories on your preferred method(s)? This is why I usually tune my springers shortly after i buy them. But I wanted to give this rifle a wearing in and I could tell this issue was apparent from time to time after long shooting sessions. Starts smooth then gradually got a tad metal to metal wearing. Not coarse or crunchy,...just not smooth as it should be.
Whenever my HW pistons were a "sloppy fit" to the receiver" (a common issue years ago) I simply installed (3) 1/4" diameter Delrin buttons around the piston skirt and glued to flat bottomed recesses. After the adhesive cured the buttons were machined them a "nice sliding fit"..........
(https://i.imgur.com/ap74tbS.jpg) (https://i.imgur.com/XKwqvP2.jpg)
The last HW springer I bought was a HW95 and the piston fit the receiver so nicely that all I did was polish the piston skirt a bit and installed after applying some Krytox GPL 205..........
(https://i.imgur.com/GonaCiX.jpg)
Personally, as long as the fit is close and the piston properly lubed I find the "buttoning" to be rather useless.
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Agreeing with Hector here. Almost nothing to be gained in reality. I have fired like for like guns numerous times where one has been given the rear split ring treatment (the latest pref for rear bearing) but seeing/feeling no noticeable difference. The same with piston sleeving.
I concluded the action of a piston flying from one end of a compression tube to another, is pretty much unaffected, provided the fit was not a disaster, but more the quality of the seal which distinguished the difference.
Real gains can be had by correct guiding, for so many reasons, but I see sleeving and buttons/rings as chasing issues that are more imagined than reality...
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The buttons always seem to fall off. The bearings, while a great idea, need a lathe and a serious head stock.
-y
When I buttoned pistons I always fitted 1/4" diameter Delrin "pucks" into milled flat bottom recesses using SuperGlue. That way even if the glue "let loose" (never had it happen) it would be captive between the piston shell and receiver ID.
A while back I did some work on a HW97 where the compression tube was fitted with "glue ON buttons" where the buttons had come loose and pieces were "floating in grease" inside the receiver. I don't know if the "buttons" were properly adhered to a properly prepared surface but the glued surface did appear to be "roughen up....................
(https://i.imgur.com/fyR9bXh.jpg) (https://i.imgur.com/X672d6e.jpg)
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I have also seen a broken rear split ring. All the more reason to not bother IMO.
Nice detailed info above..
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I was never comfortable gluing buttons on and split ring bearings were too much effort.
I did use JBWeld for buttons on a B26. Roughened the piston skirt where I had indexed the three contact points with a degree wheel (on a lathe), prepped the spots with acetone, mixed a little moly with slow cure JB, dabbed three buttons on and let it set 24. For finish I polished the dabs with fine sandpaper until the fit/clearance was what I desired.
Many rounds later still holding.
Worth the effort? Maybe, maybe not, but I was willing to go to that much trouble on a $60 gun to tighten clearances a tad.
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Agreeing with Hector here. Almost nothing to be gained in reality. I have fired like for like guns numerous times where one has been given the rear split ring treatment (the latest pref for rear bearing) but seeing/feeling no noticeable difference. The same with piston sleeving.
I concluded the action of a piston flying from one end of a compression tube to another, is pretty much unaffected, provided the fit was not a disaster, but more the quality of the seal which distinguished the difference.
Real gains can be had by correct guiding, for so many reasons, but I see sleeving and buttons/rings as chasing issues that are more imagined than reality...
Insee your point, but my guns issue is not that I am trying to keep the piston centrted when fired, but to keep anymore galling from taking place during the cocking stroke. I suppose I could polish the skirt and the tube as Ron suggested, and it would result in mucj of what I have with my other Weihrauch guns as well as my Dianas and Feinwerkbaus. Appreciate y'alls input. tjk
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Agreeing with Hector here. Almost nothing to be gained in reality. I have fired like for like guns numerous times where one has been given the rear split ring treatment (the latest pref for rear bearing) but seeing/feeling no noticeable difference. The same with piston sleeving.
I concluded the action of a piston flying from one end of a compression tube to another, is pretty much unaffected, provided the fit was not a disaster, but more the quality of the seal which distinguished the difference.
Real gains can be had by correct guiding, for so many reasons, but I see sleeving and buttons/rings as chasing issues that are more imagined than reality...
Insee your point, but my guns issue is not that I am trying to keep the piston centrted when fired, but to keep anymore galling from taking place during the cocking stroke. I suppose I could polish the skirt and the tube as Ron suggested, and it would result in mucj of what I have with my other Weihrauch guns as well as my Dianas and Feinwerkbaus. Appreciate y'alls input. tjk
Fair comment in regard the galling but i would have thought a good polish and the right lube would cure this.
Correct lubes are turning out to be really important. What have you been using..
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Decided to tune my 35 and found some slight galling on the piston skirt. Same print on the comp tube. Not enough to cause a huge concern,...definitely a fixable issue , but enough to warrant either a buttoning or a bearing insert. I did notice a bit of free play with the skirt and the id of the tube. Any thoughts or theories on your preferred method(s)?
Hey tjk,
I button the pistons of all my Springers with ARH buttons - I think they're (6) for $6. These are glued on using his instructions, I usually hit the piston with some 220 carborundum paper so they adhere better. I tried using curved water bottle plastic made with a paper punch, but these detached upon further inspection. The ARH buttons don't come off once they've made it past the cocking slot.
The only downside that I've seen from buttoning the piston, is you loose maybe 10/25 fps in velocity depending on their tightness in the receiver.
I believe they give the shot cycle a smoother & sold feel/sound when firing.
My DIY tunes usually cost me about $25 ... with the buttons costing $6 ;).
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Decided to tune my 35 and found some slight galling on the piston skirt. Same print on the comp tube. Not enough to cause a huge concern,...definitely a fixable issue , but enough to warrant either a buttoning or a bearing insert. I did notice a bit of free play with the skirt and the id of the tube. Any thoughts or theories on your preferred method(s)?
Hey tjk,
I button the pistons of all my Springers with ARH buttons - I think they're (6) for $6. These are glued on using his instructions, I usually hit the piston with some 220 carborundum paper so they adhere better. I tried using curved water bottle plastic made with a paper punch, but these detached upon further inspection. The ARH buttons don't come off once they've made it past the cocking slot.
The only downside that I've seen from buttoning the piston, is you loose maybe 10/25 fps in velocity depending on their tightness in the receiver.
I believe they give the shot cycle a smoother & sold feel/sound when firing.
My DIY tunes usually cost me about $25 ... with the buttons costing $6 ;).
Thats great Kirk. I tried the jm buttons and had ok results. But I like your enthusiasm! Thanks for the encouragement. I bought some precision plastic/poly shim material from mcmastercarr several years back and may try a quasi button/bearing attempt for a short term fix. 😁 One day i plan to buy a mini lathe and drill press,.....but that day is a little off in the near future. It WILL happen God willing. 🙏🏻
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Yeah, if I had a Mill I could try drill holes into the hard piston steel, which I'm assuming Ed did.
Or I could cut a slot in the piston with my HF Mini Lathe, but that's just too much work.
So after trying ARH buttons ... $6 cost/time involved - they're fine. I know the shot cycle is better or I wouldn't keep doing it :o. How much better is The Shot Cycle ? -> Enough For Me :D.
However, I'm also the guy that polishes the barrel (lock-up) wedge/spring set-up, piston tang and does a complete trigger tune right out of the box too ... Hence, Ruminating Perfectionist ;D
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I understand chasing perfection, we tend to do it with a favourite gun and applaud your efforts...
As another idea ...just throwing it into the pool...Has anyone heard of this new BAM coating. You spray it into a localised placed....I am thinking a piston wrapped in masking tape but the rear bearing left exposed and then this area sprayed with the BAM.
It is apparently, ultra hard wearing, low in friction and bonds as if chrome plating...
.....and there is another idea. Getting a few thou of chrome adding to the rear bearing...
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I understand chasing perfection, we tend to do it with a favourite gun and applaud your efforts...
As another idea ...just throwing it into the pool...Has anyone heard of this new BAM coating. You spray it into a localised placed....I am thinking a piston wrapped in masking tape but the rear bearing left exposed and then this area sprayed with the BAM.
It is apparently, ultra hard wearing, low in friction and bonds as if chrome plating...
.....and there is another idea. Getting a few thou of chrome adding to the rear bearing...
Can you find a link to this BAM stuff?
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I understand chasing perfection, we tend to do it with a favourite gun and applaud your efforts...
As another idea ...just throwing it into the pool...Has anyone heard of this new BAM coating. You spray it into a localised placed....I am thinking a piston wrapped in masking tape but the rear bearing left exposed and then this area sprayed with the BAM.
It is apparently, ultra hard wearing, low in friction and bonds as if chrome plating...
.....and there is another idea. Getting a few thou of chrome adding to the rear bearing...
BAM? Tell us more...
I think that chrome plating the rear of the piston would be a major PITA! First you would need to nickel the area and then apply the chrome and then hope that it does not flake off...
-Y
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I understand chasing perfection, we tend to do it with a favourite gun and applaud your efforts...
As another idea ...just throwing it into the pool...Has anyone heard of this new BAM coating. You spray it into a localised placed....I am thinking a piston wrapped in masking tape but the rear bearing left exposed and then this area sprayed with the BAM.
It is apparently, ultra hard wearing, low in friction and bonds as if chrome plating...
.....and there is another idea. Getting a few thou of chrome adding to the rear bearing...
BAM? Tell us more...
I think that chrome plating the rear of the piston would be a major PITA! First you would need to nickel the area and then apply the chrome and then hope that it does not flake off...
-Y
Its a Boron-Aluminum-Magnesium alloy, that is supposed to be the most slippery stuff known to man. I've been trying to figure out if there is an economical way to apply this stuff since I don't have a laser vapor deposition machine ;D
https://www.gatewaytoairguns.org/GTA/index.php?topic=184372.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=184372.0)
-Marty
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Lol....aghh, that might explain why we have not seen it in airguns...
As regard the chrome, i was thinking in terms of maybe a full dip off, getting done professionally like what the LP53 piston was done OEM...Its super hard wearing and no sign of wear after 1000s of rounds..
Pic is of a 1957 example slightly buffed on a polishing mop.