EDgun Based on the thread "L2 explouse in UK".

[EDgun]

Dear friends, users of EDgun products, haters of EDgun products, those who doesn’t care but is interested in what, in fact, happened in UK in the beginning of this year.

Shortly:

• There was an information bout the case in beginning of February 2023.
• Dave, the owner of exploded L2, was so kind that arranged the shipment of the remains to Russia.
• I got them in the beginning of the summer and then made the contract with the special laboratory to make the test.
• At the end of summer I got the results.

Here are the conclusion of expert, in Russian, that is understandable , for those who wants to make the precise translation – Google translator will help you, no doubt.

For those who wants to know only the final parts it sounds this way:

• Expert failed to find some production or metal fails which could lead to the explousure. Conclusion – the material, processing and manufacturing is OK.
• Based on the examine expert found out that there are much remains of the oxygen in the area of corrosion.
• The destruction started from the corrosion spot.
• The material of both reservoirs, the remains and the test one was tested to meet the standard according to the chemical proportion. It is D16T, as it should be.

Based on the conversation with the expert I can say, that they have no tools to find out what was the reason for starting the process of the corrosion, but he said that misuse of the owner could be a reason. He underlined that using the compressed air with the moisture in it (that usually happens while using the small compressor and hands pumps without the proper dryer), can lead to that result.

Unfortunately, the moisture with some addings (like oil and so on) in the conditions of the high pressure can be very aggressive to the alum alloy.

That is why I, personally, avoid using undried air and use ONLY air from the tanks, filled at the fire department or dive centers, who use air for breathing.

My recommendation to those who has no possibility to use dry air and have to use small compressors or hand pumps – use the best dryer you can find and make the check-out of the inside surface of the reservoirs on the constant base.

From my side, as the manufacturer, I cannot see any mistakes, which was confirmed by this expertise and with my light heart keep going on making the guns using all necessary measures to make them as safe as possible.

With the best regards

Ed

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[JungleShooter]

Thank you, Ed, for your extremely helpful response in all this.

I will continue to support your brand. Keep up the good work.

Matthias

 

[EDgun]

Hi Ed. It is Lukasz. It seems I matured enough to say sorry about presenting the information which was not based on the evidence. As you remember I transformed from your fan to your hater. Now I decided to stay neutral. We all need to grow up at some point in time, don't we?

Lukasz, I told you and other many times -- I am just like a mirror, if you show me agression or misuse -- I will reflect it back. If you show me normal way of discussion you will get it back as well.

In fact, I don't care about fans or haters, I more care about people to be calm and logical, in order we all would be able to duscuss the issue based on the facts, not based on the emotions. In all aspect of our life, from techic to policy

As usuall I am ALWAYS ready to be open partner to any discussions which are based on the principle of the mutual respect.

 

[ctshooter]

Ed - just a thank you for providing the testing results to set everyone's mind at ease.

 

[FelixS]

I am an onlooker who thinks EdGun products are cool, but owns none nor has ever shot one. So take that into account.
My thought is that although material, processing, and manufacturing are acceptable,there is no mention of design; is it adequate or is there a design flaw? Also, it is mentioned that user error was a potential factor where it is possible moisture got into the system. I would think having a degree of moisture and compressor oil pumped into guns is a common occurrence across the world. Perhaps that possibility was the result of casual discussion, but not an official factor? Those would be my concerns were I an owner of your product. I am still contemplating owning one, by the way

 

[Denchik]

I've bought my L2 18 July. In the main I was statisfacted with one, until i read bout this issue today. I've changed stock reservoir with composite bottle 0.36L before. Impressed with this event i started investigate my reservoir. I was wondered when i saw 90 degrees sharp corner inside. In my oppinion it isn't acceptable. This is tension concentrator under pressue. Eduard, how can you tell L2 owners "you can fill your L2 up to 300bar". But there is another pic from your sourse. There is much difference between bottoms.
I've made 3d of my stock reservoir, measuring with caliper. I didn't shape bottom of reservoir according U-type drill, which shaped this bottom with. It doesn't matter.

 

[Denchik]

I didn't investigate another reservoir yet. It is under 250 bar pressure right now

 

[Denchik]

It is how should be

 

[Denchik]

If 90 degrees corner of exploded reservoir would be rounded even with R=2 or 3mm, this and relative topic wouldn't exist. Moisture out of any cheep pumps couldn't be reason of the damage if bottom would be proper. In this case happened imposition of one thing on another one. In the expert's report is nothing bout this sharp corner. As i understand there wasn't corresponding request to expert.

 

[Denchik]

Local absence anti-corrosion coated are existing in my reservoir too. In the same places as in report. Well. The show is going on? Shall we wait torn-off fingers, jaws, balls e.t.c. I mean how many same reservoirs are filling or refilling rigth now. This is just math. This is just matter of time, that depenses of quantity same flat-bottoms reservoirs that in using.

 

[pan60]

i am very glad to see EDgun chiming in here and posting the results.
persanaly i have no plans to argue the qaulity of the cylender but i will say i beleave a robust round corner would be my choice.
as for a anti-corrosion coating would that be somthing very manufactoror would be aplying to their cylinders?
also if moister caused this corostion that lead to the failure what would stop a gun from expoding? not a EDgun Andy gun? its all under presure?
i persanly bought my compresser based on not wanting moisture in my guns i know it is costly i chose to hold off for a extra year saving to get a nice compressor so i would not have to deal with this type of issue.
and even so i do fear corrosion can cause issue that will sneak up regardless?
i am not sure attacking EDgun if fair with out attact many others?
maybe i am wrong?
and i do not own a EDgun.

 

[Denchik]

I guess cylinders bottoms were as in Edgun's pic at first. Then Engun's contractors have changed common twist drill with U-type drill without notice. It all passed by mr. Gafarov successfully. Correct me if i'm wrong.

 

[FelixS]

I guess cylinders bottoms were as in Edgun's pic at first. Then Engun's contractors have changed common twist drill with U-type drill without notice. It all passed by mr. Gafarov successfully. Correct me if i'm wrong.

THIS is what I was talking about. Although I do not know engineering, design was the elephant in the room. Change is good, and if the new design is now in place, great. But, as Denchik alluded to, why is there no recall?

 

[Dairyboy]

He did hydro testing on both style tubes in the original thread....why need to go through this again? Both styles tested just fine.

 

[Denchik]

He did hydro testing on both style tubes in the original thread....why need to go through this again? Both styles tested just fine.

It seems i missed something. I watched hydro test when he loaded his tube with around 800 bar as i remember. Ok. Test has been successfully passed. What was this reservoir i don't know. Second test i watched is when he shot in his tube under pressure with 9-mm L2. It was fine too. Awesome. Great job.
I guess it can resistand 800 bar pressure for one time.
But i have intrest how many cycles loading up to 300 bar/empting can withstand flat-bottom reservoir? Load into reservoir 300 bar, leave it for few time, then empty. Repeat it again. If it withstand even 500 same cycles, i will take my hat off. Yes, i know it takes much money much time.
Another way is attach tenso sensors to reservoir, load it with 300 bar, then take off neccesary metrics. Based 'em and other ones we will to able forecast when cylnender will damage. It takes good lab.
I won't argue anymore, i just gonna make proper reservoir for myself and have no worrying.

 

[dorcula]

Thank you Ed. Interesting reading.

However, it appears that the root cause of the incident is still undetermined. This could still be an overpressure event due to user error, could even be an explosion of oil-based lubricant under high pressure. The lab did not check the surfaces for presence of things like hydrocarbons and combustion products that would point to an explosion. It could even still be a result of some external force like the end user holding the rifle by the barrel and whacking the reservoir against some hard surface in anger. And yes of course it could still be the corrosion impacting the structural integrity of the part to the point where it's no longer able to hold the pressure it's supposed to. This is implied, but the lab report did not specifically state this was the case, it just said that the fracture originated at that corrosion spot. Or it could be a combination of several things.

Anyway. Corrosion is the only obvious issue, but it is still unclear just how much the tube was weakened by corrosion. This is actually the scariest to me: this spot does not even look bad at all on the pictures. It looks like some minimal aluminum oxide deposits at the surface, that's all. If I saw that in my own tube, I wouldn't even be concerned, I would never occur to me that it could possibly penetrate the surface deep enough to cause problems. I'd simply clean it off and proceed with my life...

Also, the corrosion was observed at the bare metal spot where the anodizing? ("black anti-corrosion coating" as the report calls it) is missing. I know we discussed it in the past and the coating is meant to be purely cosmetic, without any anti-corrosion properties considered at all, but it does look like it works to that effect. Would it be possible to improve the coating of the tubes to eliminate these internal bare metal spots as a short term fix and perhaps consider proper anti corrosion coating in the future? Unfortunately air quality is a problem for many users, properly cleaned and dried air from scuba shops or fire departments is not always an option, people will keep using cheap compressors with questionable filters or no filters no matter what the manufacturer recommends. This is just the reality. Yeah you could say it's their fault for not following your recommendations and be 100% right, but why get to that point?

 

[dorcula]

But i have intrest how many cycles loading up to 300 bar/empting can withstand flat-bottom reservoir?

According to the report, the lab checked for but did not find any evidence of metal fatigue, so here's that.

 

[pan60]

it is shocking to me that Corrosion would be the root cause?

 

[Denchik]

According to the report, the lab checked for but did not find any evidence of metal fatigue, so here's that.

Corrosion occurred first

 

[dorcula]

it is shocking to me that Corrosion would be the root cause?

No. What's shocking is how little evidence of corrosion is visible on the surface which makes this problem hard to detect to an average L2 owner.
If we believe this to be the root cause, then ANY amount of aluminum oxide visible in the tube makes it highly suspect and potentially unsafe to use.