[TheForge] Christmas Gifts [SAFETY HEADS UP]

[xlch58 at swbell.net]

Andrew Vida wrote:

>     Word of caution on aircraft valves: some exhaust valves, usually 
> those out of radial engines, are sodium filled.  You do not want to 
> put one of those into the forge.  I don't know if they will explode 
> (don't have the boiling point of Na handy at the moment), but once you 
> breach the steel, the resulting fireworks will prove most 
> distressful.  Explosion or not, the Na will be very liquid at forging 
> temperature and hitting the valve with a hammer would not produce good 
> results.
>
> One way to ID potential candidates is the shape of the face, which 
> unlike the concave face of your typical automobile exhast valve is 
> convex due to the hollow cavity inside wherein the Na resides.

Or you can do it the way I did it -- look the part number up!    The 
valve was an intake valve for a Lycoming IO-360, which is what I was 
specifically looking for Hap ( the deceased aviation mechanic) was a 
Mooney man.  Lycoming used sodium filled exhaust valves on some engines, 
but intakes were standard solid stem tulip design.  Continentals by the 
way were all solid stem.   The margin on this valve was too small to 
reface, so it was scrap   By the way, sodium valves can be found in both 
mushroom and tulip designs, so the presence of a hollow cavity won't put 
you in the clear.  In fact , most standard exhaust valves I have seen 
are of the mushroom type, with tulip style exhausts relegated to hi 
performance engines.   I have buckets full of valves at this point ( and 
valve refacers ,seat grinders, seat cutters)  as well as a centruies 
worth of aviation manuals, both my own and now those of Hap's  as 
well.   Normally I wouldn't use a valve, but did for the sentimental 
reasons after looking it up.  

Charles