Originally Posted by mattathayde
just make sure you dont give it to much of a thermal shock. if its a very high quality stem it should be fine but if its cheap there might be impurities in the metal that would let it crack more easily (also either way look to make sure you dont see any hair line cracks or anything like that before you try the thermal solutions)
while i fully suggest the tap and die (you would need a bottoming tap to make sure the threads are clear) the price of those pieces, unless you have friends with them or work metal, is not worth the cost compared to just buying a new stem (probably spend 20-45 bucks on just the tap and die, if you can find the correct threading)
Gryphon, if a piece galls together is that still the weakest point? or is it kind of at first yes until it is left for a while, also slightly off topic for solutions to use here but would one of the very low strength loctites prevent galling or no
If there were impurities present in the joint material, then there most likely would not be any galling present. Brass and chrome are fairly resistant to the galling phenomenon.
As for the thermal shock, that is precisely what is needed to force the parts to seperate. Using a home freezer and boiling water are the low ends of this application. For real stubborn problems at work, I have used liquid nitrogen and a MAPP torch. Do not try this at home!!!
As for your question regarding the strength of the gall point, I am a bit confused. The gall point is essentially a "mechanical weld", that is going to be the strong point. It would take several years for internal corrosion to change the strength. I would never use any type of Loc-tite, Never-Sieze or any other anti-galling compound on a hookah. As per federal regulations which govern food plants, none of those compounds are classified as H1 (direct food contact) or H2 (incidental food contact.) As per my previous post, I recommend Canola or Mineral oil. Just a drop will do the trick. Keep in mind that after a thorough cleaning, the oil will need to be reapplied.
To the comment regarding the cost of a tap and die, there are sets available for around $25 http://www.harborfreight.com/cpi/cta...emnumber=39425
My Syrian is tapped at 10-1.25 and 12-1.5. A bottom tap will not be needed, the stem is hollow, nothing to bottom out on. Yes you can probably get a new stem cheaper, but then you don't have any new toys
A cheaper alternative is a thread file http://www.sjdiscounttools.com/kdt2228.html
It takes more patience, and a softer touch, but it does work