Flush mounting a tube onto a can

[ReLo442]

So I cant seem to find pics of this :bangHead: which would really help but anyway.... I saw onetime where someone had sorta flush mounted a small tube into a larger tube. The purpose was to have a "reverse clearing pipe". bates maybe? Well the small tube (prolly like 6mm) had been flush mounted into the larger tube (38H pulled down). I tried this today but popping a hole, heating a line where the tube was going to go, and tried to seal and press the tube into the heated area all in one fell swoop:twitch: needless to say it didnt work at all. Ended up trashing the whole piece. Anyone know what im talking about? got pics? got tips on how to do it?

What im wanting to do is have a hand sized inline bubbler where the inline portion (the upright) is actually flush with the can. Hopefully my high tech drawing will give u the right idea. The part with the arrow is specifically what im talking about. The upper right part will be the "bowl" and then it will flow through a hole at the bottom of the upright (12mm). The can will be 38H I think. Im thinking my next try I might cut a 12mm tube length wise so i can heat the can portion, graphite a groove in there, then lay the "half 12mm" onto it making a tube.. Make sense?

Any help, insight, pics, posts, ideas would be greately appreciated. Im not gonna sleep till this thing gets done.

edit: imma tard....heres the bates vid. http://www.youtube.com/user/glassbates#p/u/17/v1CpuGUHCIE
not exactly what i want to do, but same concept just on a bubb not a pipe.

[gn0me]

The difficulty in this tech is mostly going to be getting the transition from the wall to the inside of the can to be melted in smooth. Bates is certainly a madman when it comes to highly technical work - you can see in his reverse clearing spoon that the tubing was melted very thoroughly into the walls so all transitions were smooth... I'd guess that the reason your first attempt got trashed was that there wasn't a smooth surface between the tube and the can.

Shape the can as you want, then pop a hole in spot for the tube, as close to the wall as possible. Position the tube where you want it, heat a spot on the can where the end of the tube will contact the wall, and fix it in place. Go back and melt in the seal to the tube, making sure to keep the whole thing hot as this is when it's the most fragile. Now, keeping the side with the tube facing up, melt the wall of the can, letting it drape onto the tube. It will be particularly handy for this step if you have a hand torch, especially something with a very driving flame like a single hole premix. Get the wall of the can really, really hot so that it falls onto the tube and not only sticks to the tube, but the sharp transition between tube and can gets smoothed out. You must not have a juncture that looks like O|. It will be helpful to have the end of the tube sealed so that you can later heat the area and apply a bit of pressure to round things out, after it's melted in.

I hope this helps! Be sure to post pics if you pull it off ^_^

[ReLo442]

Im wondeing if he was heating from the inside with a hand torch or something. Im gonna do some trial runs with scraps tomoro night after class before I leave town for a week. The seal at the hole is def the first thing to get sealed cuz one the tube tags anywhere on the can, ur pretty much SOL at sealing that weld up unless U pick it or add fill rod which i dont like doing. I think the next run is going to start off with a marvered channel, maybe my graphite rod, then ill cut a piece of 16/12mm tube long wise and try to lay it on there.

The whole goal was to have the downtube flush with the can. I affectively want a downstem WITHIN the confines of a straight piece of 38 heavy. the can needs to be a perfect 3" long, flat bottom, flat top (with SLIGHT dish for extracts), with the downstem flush with the side. At least thats what Im invisioning. Ill definatly post some pics if I get anything worthwhile done.

Thanks for the tips gnome. Im a lil confused by ur tip tho. It seems counterintuitive to let the can walls fall onto the tube, but maybe thats what I need to do to get the weld good and even and then marver it all back into original shape. Trial runs, thats all I can do now. I really should be sleeping but that aint happenin so ill let this bobble around in my head until I can try it out again.