solder paste

here some of them:

http://www.mvent.com.ph/malcom/sps1.htm

http://www.bikudo.com/product_search/details/116079/solder_paste_mixer.html

http://www.japanunix.co.jp/ju_en/products/UM-103.html

http://www.fancort.com/robotic/_solder_paste_mixer.html

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I am curious as to why you need to mix.... We use a 500g cartridge with air gun. Our process is remove the cartridge from the fridge, allow it to warm up to room temperature before inserting into air gun, then apply bead of paste to the stencil. No mixing because the paste already has the flux built/mixed in.

We do this with both no clean and water soluble type fluxes and both lead and lead free solder. The paste will start to dry out and then not flow/spread properly in our stencil printer if it is old enough to exceed the expiration date and not keeping the unused portion in the fridge will shorten the shelf life as well. As long as we have watched those factors closely we have not had any problems.

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Bryan,

Dyoungquist is correct. You should not need to mix solder paste. Overmixing solder paste can adversely affect it. Follow these guidelines and you should be fine:

1. Keep unopened containers of paste in the refrigerator. 2. Take one container out and allow to stabilize to room temperature. Again, mixing is not required. 3. After use, DO NOT return the opened container to the refrigerator, as condensation may occur. 4. Cover and keep the opened container at room temperature and use until empty. Do not use if it gets crusty. Alternatively, we have not had any noticable problems mixing in a little liquid flux (same type) to the paste if it dries out too much. 5. The paste we use is good for a year at 70 degrees F conditions. Yours may be similar, so leaving it at room temperature should not be a problem for at least a few weeks. 6. Store your cartridges in the refrigerator vertically, not horizontally. Storing them vertically will minimize flux separation. No recommendations on the tubs, though.

Hope this helps!

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We've used mostly cartridges for many years and I only saw separation once when a particular paste supplier had a problem. With cartridges it's just thaw and use - no mixing. We have some sites that use jars along with mixers and I've never been comfortable with them. The mixing has to be done in a very controlled way or the paste can be overheated. Every supplier I've talked to cringe at the idea of their customers using mixers, although they understand the reality of some customers not wanting to wait for proper thawing.

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