Thought I should share this with you,
got this idea today and had to try it out, worked like a charm!
http://www.anteeo.se/solder_vacuum.php
Basically you just use your vacuum cleaner and a very simple construction to build a vacuum table to hold the stencils in place while you are working with the paste.
Wow…that is the best idea I’ve seen all year.
Give that guy a medal…just made my life much simpler.
James L
Thank you very much!
I walked around with a big grin on my face all day after I made this little dicovery! 
I had a eurocard (16x10cm) with lots of 0.5mm pitch that was virtually impossible to get perfect without the vacuum! Like walk in the park after some quick carpentring!
I don’t understand. I see how it suctions the board down, but how does it keep a stencil on top of the board in place? Through holes in the board? Does it make the paste dry faster?
djohnson,
Yea…it uses vias and through holes to suction the stencil to the board…which should be a pretty good retention.
I would think it wouldn’t dry the solder paste any faster…no airflow around the top of the board (all the holes should be blocked.)
very interesting idea.
James L
Nice. I haven’t done any stenciling yet but when I do I will set this up first thing. I’ll need to find a very quite vacuum and create a small portable setup since I don’t actually have a shop.
Good work!
SFE sells (or used to?) a Stencil Alignment widget which helps with the same problem.
I finally got my vacuum setup built. I use 1/4 inch plywood (it’s what I had)
It works really well.
James L