Shit...broken manifold stud

[mardak at cogeco.ca (Mark)]

Allyn wrote:
>> BUT...
>>
> 
> okok, i wont argue here - it may very well work, but my 
> engineering-oriented mind needs to wrap around the 'how it works', 
> instead of the 'it just works'.


My engineering-oriented mind works the same way!  I don't sleep many 
nights because my mind is racing with one conundrum or another. 
Sometimes I wish my brain had an on/off switch...  :)

My (uneducated) guess is that the wax doesn't burn off like an aerosol 
based penetrant would at the high heat levels required to cause movement 
at the stud/part interface.  My thinking is that the wax keeps wicking 
and working it's way down (or up!), cleaning and lubricating, long after 
the PB/Thrust/whatever would have "flashed".

I believe heat is still doing the work though.  It's what's allowing the 
wax to penetrate.  BUT heat alone doesn't necessarily guarantee success. 
  If you heat a stud or part to a dull glow there probably was a moment 
or three when there was movement between the stud and part due to 
different rates of expansion/contraction because of the deliberate 
uneven application of heat to the two parts (not to mention the 
interaction between dissimilar metals).  There is probably a very narrow 
"window" of time where force alone can be applied to further free the 
seized stud, whereas if wax was applied it would wick it's way down (or 
up) in those instances of movement, cleaning and permanently lubricating 
the threads.

I'm not saying penetrating oils don't work at all, but perhaps wax 
actually penetrates deeper/better because it doesn't burn off as 
early/fast...



> how can melted wax possibly:
> a. break up corrosion that is binding threads


Heat and force breaks it up - the wax wicks in and cleans/lubricates the 
threads.


> b. correct possible siezing of threads due to galling


Heat might still cause movement, even with galled threads, allowing the 
wax to penetrate? (where there is movement, there is a potential gap 
created when the parts move relative to each other)


> c. correct possible locking of threads from bottomed bolts/nuts


I don't know if anything can "correct" this situation (other than 
force), but I believe an application of heat/wax will still help.  Even 
a slight reduction in overall friction between the threads might mean 
the difference between the stud snapping, or being removed successfully. 
  As with many things, you throw everything (knowledge and materials) 
you have at the situation and hope for the best...  Sometimes you have 
to admit defeat and get out the drill (or farm it out to someone with an 
EDM machine).  I wouldn't doubt that a high percentage of "impossible" 
seized studs are both bottomed out and corroded...


> it just doesnt make sense to me. how can wax possibly peentrate 
> something that some PB Blaster wouldnt be able to handle. the wax is 
> simply a thicker material (even melted).


Like I mentioned above, my guess is that PB Blaster would burn off at 
the "dull glow" temperature required to affect the bond between stud and 
part, whereas the wax will still penetrate.

Also, you may see melted wax as being "thick", but maybe "something" in 
the wax is actually very thin and does the penetrating, but all we "see" 
with our eyes is the blob of wax.  I have no clue what the $#*@ I'm 
talking about here, so I'm basically talking out of my ass, but I'm 
guessing that wax is made up of many "components"...  I dunno,  I'll 
shut up about this before I make myself look stupid(er)...  :)

Any thoughts on my thoughts guys?  I'd like to know myself why it works...


Some other thoughts about removing broken studs came to mind, so I may 
as well spew them out while we're on the subject:

If you don't have a candle, a crayon will work as well.

Just because you got a stud to start turning doesn't mean you can bust 
out into a happy-dance.  I've snapped many a stud after prematurely 
proclaiming victory.  Everything can re-seize just as easily as it broke 
free as everything cools/contracts.  If you're already turning it out 
near the "yield limit" (?) of the stud, it doesn't take much extra 
resistance to overcome that limit and twist the little bastard right off.

The stud usually gets tighter as everything cools, so you might have to 
reheat/wax it.   It also helps if you can get the stud moving quickly 
after heating it since when you are moving the stud back and forth 
(after initially breaking it free - even just a little) less heat gets 
transfered to the stud (which keeps it from expanding in the hole).  I 
usually set up my vise grip to the right tension beforehand, and have it 
and some wax ready to go.  A helper is handy to have around to quickly 
hand off the torch to, so you can get the visegrip and wax on it quickly.

If you hear "screeching" it's a good thing - keep moving it back and 
forth.  It's when you don't hear anything you have to worry...  :)

Tapping on the stud with a hammer can help break corrosion.  The first 
thing I usually do is give it a few good strikes with a hammer.

Hmmmmm  what else can I say about removing studs...  Well, I think 
that's it...

So, although I don't necessarily have scientific proof, sometimes you 
just have to chuck science out the window and take a tip like this for 
what it is - an old Blacksmith's method that's been handed down for 
generations that simply WORKS, and, dare I say, works better than 
anything else out there - even today...  Try it for yourself...

Mark.
75
77
80 S
81 S  x3
81 Caddy