need help with fume trap cracking

[Zed]

So I've been having issues with dab rigs cracking when I fume trap gold and silver using the China cobalt and Simax clear. I use Simax standard wall so I can sleeve a wide variety of sizes of the cobalt with it, stuff shrinks up nice and I don't have to worry about the cobalt closely matching the clear, I can sleeve encase 25mm cobalt with 50mm standard clear, or 32mm cobalt or whatever as long as its within a 1/3rd to 2/3rds range of the clear. Anyways I have been having issues with the dab rigs cracking after the fact, I'm hanging out with a woman who I sold a rig too 3 months ago and she swears that it broke on its own a week ago. I know the China tubing colors aren't really that great but the fume > encase tech is such a dope technique for the time it takes, fast and looks nice. I had no problems with spoons but it seems like it might be unstable for multiple seal stuff like dab rigs? Should I try a different brand of clear for encasement, longer annealing schedule or better flame annealing? Anyone else having issues with this tech and color combos? Any insight appreciated, thanks.

[brads]

Never mind. I just re-read your post and realized my suggestion wouldn't work because it would hide the fuming.

[BORO]

I would try anneling the china tube on its own, before I used it.

I know I can't get jade white to survive on its own, incased or not.

If I Anneal it first, its really stable. No issues clear coated.

^unfortunately, if it takes months to crack, you wont have any clue if its working.

Looking under a scope may help? The cobalt may be too dark and hide the stress?

I would need a picture of said crack to make a real educated guess.

Lots of production rigs I see, crack close to the gong fitting. Either from rookies with the dab torch doing a sloppy job heating it, or just from extreme heat cycles.

"I was just trying to get the reclaim out." ( I slap my hand to forehead)

[D. dino i ninjah]

Its finicky at best .. working it like repulling a larger size down to smaller tubing might help also.. but my theory on this stuff it that the glass was not made for multiple reheats so the more you work it the less compatible it becomes ? . But I have seen where others repull and twist the tube before using it .. to even out the walls ..

[Zed]

Ya the woman who told me it cracked is a stripper, I have trouble believing anything strippers say. I may be getting scammed here but I have noticed that the encased cobalt is pretty shocky on its own and the amount of fume you put down seems to make a difference, more fume means more shocky. I agreed to replace the rig, so I'm on the hook. I think I will keep this style for spoons and small hand pipes and not larger dab rigs. If I make any more several hundred dollar rigs I will coilpot cobalt and avoid the China all together. Using China for anything other then cheap prodo tends to bite me in the ass, but this tech is just so tempting.

[LooseSeal Baller]

I have trouble believing anything strippers say

probably wise...

[bowlpusher]

Using China glass will bite you in the ass err time. I have fumed a bunch of it in the past and have seen that it checks more often when the glass is encased and not very clean. i would also suggest not making it more than medium wall. i would suggest encasing jet black tubing in clear and using that instead. A little more expensive, but if pieces don't crack you are saving money in the long run and making better quality pieces.