Pneumatic speargun mods

I did, opened two holes too much so decided to leave it at that. I'm wondering as to the efficacy of that in the first place. Maybe some breaking action on the piston is necessary so it doesn't hit the muzzle with too much force. It is an easy mod to do though if you don't get carried away. In this case it doesn't matter as the muzzle was the only deteriorated part of the gun and I'm probably going to go with a muzzle kit instead of replacing it if I ever go that route.

I posted before about finding this Cyrano 1100 out diving one day. It looked like it's been submerged for at least a year. I cleaned it up and modified it the same way as the the gun in the beginning of the thread. Additionally I removed the reducer chamber which proved to be easy. I plugged the pressure selector lever hole with two part epoxy.

Scraping the barnacles off of the barrel most of the paint came off. While the gun is perfectly usable without the finish I still wanted to cover it with something. I didn't want to use tape as I know it to start fraying after a while. I recall there was a discussion about what to use and I suggested shrink tubing. Tin Man then found a source for the shrink tubing which was 2" in diameter. I finally got around to putting the shrink tubing on the gun today. As you can see in the last pics it turned out pretty good. I used a heat gun very carefully so as not to burn the tubing. It took out all the air pockets very nicely. Tin Man suggested to leave extra length of tubing at each end to compensate for length shrinkage. I kept this in mind but still almost F'ed it up as it shrinks quite a bit. Before the final shrinking I was able to slide it from the side that had enough towards the side that was coming short. Then after shrinking it tight I had to trim off less than .25" at the muzzle end.

Firing the gun as I found it.

http://s152.photobucket.com/albums/s170/da4095/Spearfishing-Videos/?action=view&current=20080802FoundSpeargun.flv

Before cleanup.

After most of the cleanup was done.

With the shrink tubing on.

Thanks. Harry, do you know of a substitute for the o ring on the piston of this gun that I could use instead of buying the $25 kit? I really don't want to invest money in this gun. I grabbed an o ring from pep boys auto parts. It fit good but when I went to put the piston in the barrel it had too much diameter. I'm thinking of grinding the o ring down a bit but am not sure if the rubber can take that kind of manipulation without losing its sealing properties. I'd rather use a correct size o ring.

Jeff, the color and texture is right on, I couldn't ask for better. It's as good as you see in the pics. The tubing is fairly thick so banging it on something is not likely to cut the tubing and expose the metal underneath. Ideal would be if the tubing had some glue then I'd never worry about it sliding off, but I tried to move it and it's not going anywhere. The question is how it will hold up after exposure to salt water and laying around in the sun. There's also the question of whether the glue would create bubbles between the tubing and the barrel.

Harry, Scubas world is pretty far for me to go for one small item like that. Can you please give me directions or the name of the other place you mentioned. I still have some oil that I bought at scubas world, the same they use in the guns they work on. If I had to use something else I'd use another fine oil like suing machine oil. I've had good results with it before. Do you recommend something else that is commonly available?

Thanks.

Quote from greekdiver

you can go to an oring store west of Atlantic that sells individual orings for 10 cents a piece.

What about this place?

Thanks, I will check it out.