I have been doing some work on a totally unused Sporasub "Stealth". First the rear tank to grip joint gap was too big, so I let all the air out and loosened the muzzle before tightening it up a bit more, then re-pressurized the gun. You always get a slight gap as everything takes up with the internal air pressure, but as supplied the gun was not properly tensioned up. I tried the power regulator and it seemed impossible to push it to the point where the lever could revolve down to the lock position in the selector gate, so I depressurized the gun again and took it completely apart, a task that I am very familiar with. I checked the alignment of the power regulator block's port on the selector rod piston and they were slightly out even though there is not much scope for movement as the pegs on the rear of the regulator block index in the front of the rear handle molding. The power selector rod had no obvious bend or wobble in it, so I twisted them into alignment, placed the selector in the "low power" position to plug the port and tightened up the inlet valve body that holds all the rear end parts together in a clamping action. I tried the power regulator, it seemed a bit tight, but now it worked as it should with a push of the thumb. I reassembled the gun and took it up to 400 pump strokes, then tried the power regulator again and, you guessed it, the thing is as bad as it was before. As everything inside moves slightly under pressure the alignment must be going out. Now I have never had that problem before with a new gun and I guess the selector rod must be the culprit, but the reason for posting is what I found next on the muzzle. Bear in mind that this gun has had the muzzle removed and tightened twice since it left the factory, but when I took the gun out of a bucket of fresh water after checking for air leaks at each end I noticed that the black coating around the muzzle relief ports had come away in a crescent shape on either side of the holes. Now the metal locally flexes and returns to shape after the tightening or loosening torque is released, but that should not affect the coating. Not much material has gone, but under a jeweler's loupe the coating seems to have flaked off leaving a wavy demarcation line to the bare alloy. Checking the muzzle nose end which I rest on a rubber flip flop for pumping the gun up I found the color there was now a blue-black with the base metal starting to become visible through the remaining coating which was becoming almost translucent in places. There was a blue-black smudge on the flip flop where the muzzle had pressed into it with each pump stroke indicating that the color was rubbing off there aided by the slight oil film on the muzzle. Now this makes me wonder what this coating is as I have never seen anodizing behave this way before. I have 40 year old Mares guns that have muzzles that look not much different bar usage scratches from when they were new. Anodizing has come off through abrasions or knocks against sharp objects, it has never washed off before in a bucket.
I am wondering if anyone has also seen this happen on late model Mares guns (the "Stealth" is a Mares "Spark" as Mares owned Sporasub when this gun was produced) and maybe a sub-contractor (in China?) has been fiddling with the coating process to make it cheaper and possibly as a post-application to hide assembly scratches. As the coating thins out elsewhere on the muzzle I can see slight scratches which I have not inflicted, so they were under the initially flawless gloss black muzzle finish when the gun came out of its plastic packaging bag. It will be interesting to see what happens when this gun hits saltwater for the first time!
I am wondering if anyone has also seen this happen on late model Mares guns (the "Stealth" is a Mares "Spark" as Mares owned Sporasub when this gun was produced) and maybe a sub-contractor (in China?) has been fiddling with the coating process to make it cheaper and possibly as a post-application to hide assembly scratches. As the coating thins out elsewhere on the muzzle I can see slight scratches which I have not inflicted, so they were under the initially flawless gloss black muzzle finish when the gun came out of its plastic packaging bag. It will be interesting to see what happens when this gun hits saltwater for the first time!