This is a re-submission of an old post of mine because the picture links had all broken. The discussion was of why sometimes the fusing fails on just one or two of a chain of several shells, and we started on the basic QM to QM joins on a chain for simultaneous lift. Now it has been taken out of the original context, I must stress that there are certainly plenty of other techniques used with probably equal success rates, this is just how I was taught by people who have put a lot of thought and research into it and it works very well: For a "normal" chain of QM'd shells it is a 90 degree Tee (each shell's leader going into a small slit on the edge of the QM feeder). See how much blackmatch is actually pushed down inside the sleeve: 1. 2. 3. 4. Or for an angled joint: 5. 6. Alternatively you could go in on the top face instead of the edge, again only a small slit and the match pushed a long way down inside the sleeve. I use this a lot now, but note the "plumbing" is not now a sealed system. There is an untaped area in between the two bits of QM: 7. 8. 9. ------------------------------------------ On the other hand, this is what I used to do... (Note not much overlap): 10. 11. 12. 13. ...it's better when it's done on the top face - 2 or three times more overlap but more damage to the integrity of the sleeve (think gas flow again). This is how I've been known to do it when in a bit of a hurry: 14. 15. 16. And this is what failed (in the original post) on a cross piece (the horizontal piece is actually threaded through behind the strings but in front of the sleeve, so its quite strong: 17. 18. 19. 20. Now that seemed pretty secure, not much overlap but it made GOOD contact. It still failed though...The visco fuse was on the downward arm and it was one of the side arms that failed. When we looked at the remains, it looked like four strings had vanished up the tube for about 4-5 inches, but one strand was still just sitting there. Weird! But I must admit, it didn't follow the rules of gas flow that Shellscape are so keen on.... 'They' always say that when you have finished a joint, you should check that the flat QM envelope can still be opened up into the round tube as it will do when the gas pumps it open. Again, think plumbing! At SS, we also usually used two layers of parcel tape rather than the gaffa tape I used in the pictures, but I didn't have any to hand. There's a really quick, neat method of doing the triangular taping that I might do some action pics or even a movie of it sometime!