Rubber Problem...

[scar]

About 2 weeks ago I bought a brand new pair of black bands for a beuchat speargun which was given to me. They were of the screw in type and i noticed that both bands had about 2mm of rubber exceeding beyond the screw cap. After 2 days hunting I decided to try and load the wishbone onto the 2nd notch....and after stretching my back muscles to their utmost I menaged to do it. However, afterwards, while rinsing my gear in fresh water, I noticed that the right band had somehow started to slide out of the muzzle screw cap. The 2mm rubber stump had travelled into the cap and is now 2mm INSIDE the cap. I suspect this happened when I loaded the thing on the 2nd notch.
Since I'm still a newbie and since this pair of bands are the first I have ever changed, I need to ask:
1) Is this normal?...I mean the left band is still the same as when I bought it. It's the right band that's worring me.
2) Do you guys think I should buy another pair? Mine are still relatively new (only a couple of weeks old) ...and they still have plenty of energy. However I recognise the potential risk of the band which could come out and backfire on me when the gun is loaded so I wouldn't hesitate to get another pair if this isn't at all normal.
3) Is there some tip or trick which you do to a new set of bands BEFORE installing them on the gun in order to eliminate the risk of them pulling out of the screw caps? I never did anything to them....just screwed them in.
4) and finally....do they have to be just hand-tightened or do I need to use a gripper or pliers to screw them in really tight. I just used hand strength till I couldn't grip them anymore - but don't know if this is correct.
Thanks for your help.
PS: The bands are of no particular brand name. I guess that was my initial mistake. Next time I'll stick to a brand name.

 

[sickbugs]

it'll probably pop out soon, there is a small lead ball inside the rubber under the narrow neck of the cap, it slipped. i had it happen to me when i shortened my bands on my beuchat, maybe yours are too short for the gun u are using?

you dont need to buy new bands, you can put the cap back on if it comes off, but it will ruin a good diving day (especially if the rubber catches your finger as it pops out, i busted a fingertip when that happened to me) maybe carry a spare set of bands with you?

no tips or tricks i know about, u just screw em on, and you dont have to put them on too tight either, hand tightening is enough, just make sure that they are screwed in fully before u dive.

i have new bands on my mundial, "cavalero megatonne" they are called, metal caps, they feel really solid and they give a nice shot, i think they are 20mm but im not sure, if you find some in your dive shop, id reccomend them how long is your gun?

 

[scar]

Hi sickbugs and thanks for your early reply.
My beuchat was given to me by wife's father and it's a cavalero - just on the lower side of average - and that's not mentioning that it's only 90cm long. However since I'm still a beginner, I think the lack of punch and also the lack of range are adequate to start off with. Your mundial is much better!! I honestly would like to get a bit more practise and get a better hand on things before progressing onto a longer and better gun. (still doing research on whether to go for a pneumatic or a better band gun)
Anyway, I never knew of the small lead ball! The bands are totally solid as far as I can see. Don't know where and how they could insert a lead ball in there, but it makes sense - and it also explains why only the right band is slipping, when one considers that both bands were subjected to the same tension. Probably the ball must have slipped then. The bands I purchased were measured against an old set which were still screwed on the gun - but had seen better days. The latex was all frayed and cracked. Nevertheless, I did get the same length - only black instead of yellow (read somewhere that black seem to last longer).
Yeah, that's what I'll do. I'll get an extra spare (and this time, I'll try to find them megatonne) to carry around wif me. Knowing my luck, the biggest fish will suddenly apear restless in mid water JUST shortly after the stupid band pops out!! In the mean time I'll try my luck using these bands ONLY ON THE FIRST NOTCH. Then we'll see!! (though I must admit, I did try to slide the cap back to its original position - but after considerable heaving and huffing, i gave up on it - with a sore thumb) They best part? - The cap didn't even budge!! If the band did pop out, then I'll try (half-heartedly) my best to get it in again. Though I wouldn't bet money on my success.
Just hand tighten them. Got it. I trust it that the same goes for the wishbone end.
Thanks a lot mate.
Happy hunting. Dive safe.

 

[Huan]

Scar
You may be able to refit those threaded collars to a 16mm band but it is hard work.
forget it with 18 or 20mm bands, you won't do it.
The little locking ball is usually secure I have used plenty of screw in bands and never had a problem.
Try sticking a small allen key or rod down the centre of the rubber and push the ball to seat it.
the reason that you can't see the hole is because the rubber is squashed inside the screw on cap

 

[Alison]

I think there is a fault with your bands, can you take them back to the shop? Just one thing that Sickbugs said, are your bands to small for the gun? if you measure the rubber on the inside of the two screws it should be "about" 1/4 of the distance between the screw holes on the gun and the trigger.
Even better why dont you get shut of the metal wishbones and upgrade to dyneema ones, get a small hammer and carefully break off the offending screw cap, remove the ball then follow Victor Abellans excellent instructions for band tying (click on the link at the bottom "galaria de imagenes"