Solder paste pneumatic dispensing. Help needed.

[2camjohn]

Hey Guys

I recently got myself one of those pneumatic solder paste dispensers. To take the wrist strain out of pasting boards.
I cant use stencils because its for prototyping.

The paste I get in a tub seems a lot thicker than the stuff pre loaded in to hand syringes. Forcing me to use a larger tip than I used when hand dispensing, but I dont really mind that.



The biggest problem im experiencing is that the paste really, really, REALLY wants to stick to the tip of the needle instead of the pad.

This is causing a lot of wasted time and solder paste as the same pad sometimes needs to be done 2 or 3 times before its right.


Just wondering if people experienced with this setup can offer some guidance?

Should I warm the solder paste above room temperature to make it less viscous? If so, how?

Can I add something to make the solder paste less viscous?

Should I try putting something like flux on the board to make the solder paste want to stick to the pads better.

Is the solder paste for dispensing by syringe different from regular solder paste bought in tubs?


Any info or opinions appreciated.

John

 

[2camjohn]

Would vigerous stirring make the paste thinner?

I compared it against the paste i have pre loaded into syringes. They are a lot less viscose.