Solder paste syringe tips

[jgalak]

Ok, another dumb question:

I got a syringe of solder paste that came with 3 removable tips, each tip with a tiny stainless tube (plus a "dummy" tip for plugging the syringe when not in use).  I suspect I'll be using this syring way more than 3 times - my boards tend to be tiny.

Is there a good way to clean the tip?  It's currently full of solder paste.  Can I push it out with a pin (if I can find one fine enough)?  Water?  Something else?  Just buy more tips?

[Teledog]

If a pin/needle works, by all means use it..a bit of IPA also helps to clean it.
Short lengths of stripped 30AWG wire-wrap wire work if it's not too clogged/dried up.
Larger diameter (lower numeric gauge), and shorter needles also work better for squeezing out the paste.
If it's a small project, I tend to just squirt out a small blob on a scrap surface, sans syringe tip altogether, and apply it to pads with a pin/short wire

[nanofrog]

If it's a small project, I tend to just squirt out a small blob on a scrap surface, sans syringe tip altogether, and apply it to pads with a pin/short wire

+1 

Far more convenient this way, as there's no tip to clean. FWIW, I've found even a toothpick will work for application.

If you're working with a larger project, the plastic cone shaped needles don't require as much pressure on the plunger to apply the paste. Next step would be get paste in a jar and apply with a stencil and use a reflow oven.

[jgalak]

I was using a stencil.  Probably didn't need the spring tip.  Oh well.

[Ian.M]

First check your paste's flux is fully soluble in IPA.   Then store the tips in a small tightly sealed glass jar with a few mm of IPA in the bottom.  In a solvent saturated atmosphere, the paste in the tip cant dry out.   Blot off as much IPA as possible before use and discard the old paste in the tip.

[nanofrog]

I was using a stencil.  Probably didn't need the spring tip.  Oh well.

Nope.

Oh, and stencils are easier to clean IME. 

[jgalak]

IPA?  I'm assuming you don't mean the beer?

[nanofrog]

IPA?  I'm assuming you don't mean the beer?

IPA = Isopropyl Alcohol

You could also use Klean Strip Denatured Alcohol (non-green variant). As it's just ethylene and methylene, it won't leave a residue once it's all evaporated (unless there's still flux residue remaining). SDS for it (formulation is on pg. 3). Cheaper than 99.5%+ IPA ($15.98/gal). 

[jmelson]

I was using a stencil.  Probably didn't need the spring tip.  Oh well.

Oh, definitely SKIP the syringe when using the stencil.  You can mix the paste better from a jar.  Otherwise, the solder separates from the flux, and becomes troublesome.  I just dip out a glob of the paste onto the stencil, and then (against recommendations) put the rest back when done.

Jon