Homebrew PCBs

A few of you might know i use bicycle valves with the valve ball or hose  
removed in lids on solvent bottles and other stuff that does not mind  
contacting metal, like this:
<http://tinypic.com/rs63ur.jpg>
This is great because it allows you to take out tiny amount without  
obstructing the large opening with something like a rag, which  
contaminates all the solvent if you use a oily or dirty rag. It has one  
disadvantage though, the little black plastic caps just love to get  
misplaced, and you need to remove them beforehand, and replace afterwards.

Yesterday i had an idea how to solve this problem. I was looking at  
commercial dispensers with valves (at least $30 a piece an more). After a  
bit of thinking (passing by the "pull to open" valves on drink bottles and  
detergents finding them unsuitable) i finally found a solution that seems  
to work great. I took a car tire valve, and removed all the rubber on the  
outside, and cut a few mm off the threads on the tip (remove valve insert  
first). Then the valve insert is replaced and the tiny plunger to open the  
valve now sticks out a few mm. Mount in cap like this:
<http://i1.tinypic.com/rs62c5.jpg>

Now if you hold the bottle upside down, and touch the plunger against a  
rag, or a surface you want to clean, or the inside of a countainer in  
which you want to put some solvent, it will open the valve and let out  
some solvent. The little spring in the valve will keep it closed at all  
other times.

I haven't had much experience with it yet, but it sure seems to work great  
and ideal for my purpose. The only danger is if the bottle topples over  
the plunger might come to rest against something causing a leak. If you  
fear that you can lightly screw on a valve cap during storage (so that it  
doesn't depress the plunger of course). I hope the small seal inside the  
valve will be OK with the solvents i plan to use it for.


Anyway, i have spent lots of time thinking about how to solve this  
problem, and i thought some of you might be having the same problem with  
the large openings in solvent bottles, so i thought i better share the  
idea.


ST