Where to buy solder paste

Thread Starter


Joined Feb 2, 2008
I am going to be trying my hand at an all SMT layout for the first time and I am trying to find solder paste. It seems like it is really expensive to buy it online and I am not even sure which one to buy. Where do people typically buy the stuff and what parameters should I be looking for? Also does anyone in the New York/New Jersey area know of a place where you can just walk in and buy this type of stuff?

Thread Starter


Joined Feb 2, 2008


Joined May 11, 2009
Remember that solder paste is like "fresh food" and do have a shelf life. Typically around 4-6 month shelf life at room temperature. Water Soluble pastes get a little less shelf life. What you probably will run into is that paste thickening up over time which is attributed to the flux medium reacting with the solder powder. You might also see some separation of the flux. Symptoms of expired paste or paste that has changed significantly from its original properties include: Significant Separation of flux and powder, Increased viscosity (leads to difficult dispensing), and in some cases large air bubble formation in the syringe.
The expiration date should be on the label. Many vendors will request the syringed solder paste be refrigerated to extend the shelf life. And that is trick you also should use. If you do not find any date on the label. Do not purchase it. No matter that they say in the shop.
Last edited:


Joined Jul 16, 2011
I believe that it has something to do with the tin content. More expensive pastes have higher levels of tin, which makes the paste melt evenly at the same temperature.

For the sake of $2.50 it might be worth giving the cheap stuff a try. If it doesn't work very well, then you've only lost a couple of bucks.


Joined Aug 12, 2011
I've been looking at solder pastes as well, been doing all my soldering by hand with wire solder since forever. Been thinking about doing some reflow.

Like wire solder, you also want to consider the content of the solder itself. I think I would avoid the lead-free stuff. It has a much higher melting temperature. Similar to wire solder, I'd go with the 63/37 or 63% tin, 37% lead. The 62/36/2 is also good, has 2% silver and actually has a slightly lower melting point than 63/37.

Unlike wire solder, it seems there's little option on the flux base. It seems most of them are "no-clean" flux. Probably just have to take what you get on that.

You can get 63/37 paste from China pretty cheap by going to eBay or DealExtreme, but I have no idea if it's any good, plus shipping takes a while. Otherwise, it's expensive from the usual vendors like Digikey, Mouser, Newark, etc. I did find this one and it's Kester, but who knows.