Just groping in the dark here ( I know, I've been warned before about that ) but does anyone know the specs on these Korean vapes.... I bought this well engineered piece of kit recently.. and what I'm looking for is the thread size on this part.... The thread on the left ( The big one ) is 6.9mm according to my micrometer and it aint BSF or BSW... Do they make it specifically awkward to prevent copyright infringement ? This is a 7" vape and I want to cut it down to a 5" vape by simply removing the bottom 2" and threading the cut to accept the threaded screw/pricker holder Both ends have the same thread except for the part that goes into the stop cock.
The size of the tread is M7 x 1 mm. I had already some experience with this vaporizers: Using the Stainless-Steel Tube with the brass nozzle, the vaporizer was always leaking between tube and nozzle. To avoid this, i changed the tube into one self made of brass. This works without leaking. Regards - Steven
Differential expansion of the metals eh? A fundamental factor to take into account in engineering design.
Thanks for that Stephen.... I'm gonna have to invest in a lathe M7x1mm ...I'll work with that. I'll try and track down an appropriate tap....
Glad I stumbled across this thread as has helped solve a problem with a Kayen heater. Which was shooting yellow flames out of the burner after about 15 mins or so of operation. Had installed one of these Korean vapourisers which I had bought from a Taiwanese seller. Have just pulled the vapouriser apart and applied generous amounts of muffler putty to the threads. When I pulled the vaporiser apart found had not put any of the grey putty on the jet thread. Happily now all seems to be burning well, no yellow flames.
I used the sealant once and made an unfortunally experience: The sealant expanded under the heat while running the lamp and the tube of stainless steel get cracked in the area of the thread. However ... could be an option ... to try out. Regarding the material "stainless steel" i discussed this problem in a geman forum, and one member thinks, that could also a problem of the profile of the thread combined with the to low limiting friction from the material as self. That sounds plausible for me. (I tried also, to compensate the different expansion of the metals with a washer made of cupper - that mathematically should work but in practice the nozzle nevertheless gets loose)
@Paul Burnell There was a recent thread about using exhaust paste or similar to help seal leaking Tilley burners? Perhaps a small dab would help? You could try with a small amount first in case you wanted to dismantle?
I would be more inclined to use a high temperature liquid thread sealer like Loctite. It won’t expand the thread interface. Old Tilley vapourisers had a threaded brass base and steel vapourising tube. I don’t think they were sealed except by friction. Cheers Tony
Okay, probably i explained the experience i had not clear enough. I believe, that the original tilley vap works in this way without leaking. I had no leaking problem at the side of the brass base either with the korean vap. It was leaking only at the side of the nozzle
Oh… my apoigies for the misunderstanding. You won’t be able to use tape in there. Far too hot. I would try to find a high temp Loctite. You might get away with using nickel grease on the thread. Best regards Tony
Thanks Podbros, that sounds very promising. when I eventually get back around to this project I will give that a go. I've gotten sidetracked with a Bialaddin 300x that I'm stripping down at the moment.
No, in my opinion leaking is a problem of the material (stainless steel), as i described about the dicussion in the german forum in post #9. Or are you talking about the crack using the sealant? There i don't know. Could be or also could be to much expansion of the sealant?
I was thinking of anything that can be produced on a production line can produce a lemon. I have driven a few in my time. In Ireland they are called a "monday morning car". because whoever built mine must have been hung over from the weekend.
You might want to try copper/graphite-based antiseize compound as the sealant. Since it won't set hard like muffler cement, therefore, also less likely to cause damage due to heat-induced expansion. The difference in thermal coefficient of expansion between brass and stainless steels is not too wide. Brass would still have higher values. I'd assume you were using austenitic stainless steels like 304, 310, 308, 316, etc. I would think it wouldn't be too much of a problem if the brass nozzle has the external thread while the enveloping stainless steel tube has the female/internal thread. The brass nozzle should expand more than the stainless steel tube if temperatures are the same. So, rather than loosening, it should have been tightening instead?? The member at the German forum might be right. It might be the thread profile or some irregularities on the thread of the stainless steel tube. From my experience, it is sometimes difficult to get a smooth threading on stainless steel with a normal die or tap. Those bits for threading certain tougher chromium-containing materials are usually made from even tougher materials like tungsten, their carbides, etc.
@MYN a very interesting observation, and I can see the logic of the expanding brass sealing rather leaking........
