Solder Paste Newb, Question about storage and shelf life? - Page 1
Forum section: electronics / beginners

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: December 07, 2018, 08:00:45 pm
content: I have been doing electronics for about 6 years now including lots of smt, but I always hand solder using a small tip and .033 solder or finer. Yesterday I was at my local home depot and was surprised to see they have actually started selling digital Weller stations along with decent solder and silver bearing solder paste.I picked up a tube it is "Solder It" brand, here is a link to the producthttps://www.walmart.com/ip/Solder-It-SP-7-Silver-Bearing-Solder-Paste-7-1-Gram-Syringe/48345692?wmlspartner=wlpa&selectedSellerId=1235&adid=22222222227036523273&wl0=&wl1=g&wl2=c&wl3=57790002698&wl4=aud-481962823846:pla-90126840818&wl5=9031411&wl6=&wl7=&wl8=&wl9=pla&wl10=112354589&wl11=online&wl12=48345692&wl13=&veh=sem&gclid=CjwKCAiA0ajgBRA4EiwA9gFOR7XU3jwsHK1v-ivTlJ9xBiaH1DSQVCySJ9SPMIO7nlFviW03eKWupxoC0EsQAvD_BwESo is this just standard solder paste? There was no expiration date or storage directions. Im under the impression paste only lasts 6 months and needs to be stored in a refrigerator, this was just out on a shelf? Can I just leave this stuff out on my bench and it will stay good forever, or do I need to keep it stored cool, will it expire, if so how do I know it is bad?

author: Bassman59
author_rank: Super Contributor
timestamp: December 07, 2018, 08:09:34 pm
content: Quote from: rwgast_lowlevellogicdesin on December 07, 2018, 08:00:45 pmUnfortunately, the Solder-It website haszero useful informationabout their product.

author: Nusa
author_rank: Super Contributor
timestamp: December 07, 2018, 09:32:07 pm
content: Actually, on their support page it has one useful item about it:http://www.solder-it.com/manuals/sp7msds.pdfThe shelf life is probably pretty long, but I would not let that stuff touch real electronics. It literally contains petroleum jelly. The Zinc Ammonium Cloride doesn't excite me, either.Electronics is, at least for marketing purposes, an extremely broad term. If the paste isn't advertised for SMD applications, it likely isn't suitable for our kind of electronics. Advertised shelf lives are usually about 6 months if properly sealed, double that if refrigerated when not in use. Those tend to be conservative numbers, so reality is longer, but eventually it becomes unusable.

author: rstofer
author_rank: Super Contributor
timestamp: December 07, 2018, 10:04:05 pm
content: Amazon carries it. I would suggest the versions that include a dispensing needle and pick leaded versus lead-free as you wish.https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=solder+pasteFree Prime shipping on most and I would buy 63Sn/37Pb for my projects.Do another search for paste flux, you will need it!

author: malagas_on_fire
author_rank: Frequent Contributor
timestamp: December 07, 2018, 10:06:55 pm
content: I heard that some people put in a small refrigerator or really on a concealled part of the refrigerator... I don't know if it is a good idea or not because of possible contamination with micro organisms , Humidity unless very sealled. I could be wrong and talking crap.. but who knows...

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: December 07, 2018, 10:15:20 pm
content: Quote from: Nusa on December 07, 2018, 09:32:07 pmThis is pretty much a standard lead free "plumbers" paste, not for electronics. The plumbing stuff lasts forever damn near.

author: Brumby
author_rank: Unknown
timestamp: December 08, 2018, 05:13:53 am
content: Quote from: malagas_on_fire on December 07, 2018, 10:06:55 pmUnless someone knows something that I don't (which is always on the cards) the only risk in putting it in the refrigerator is if someone takes it out and spreads it on their toast.Just put it in a well marked plastic bag and stick it in the fridge somewhere out of the way - and let other members of the household know what it is and to just leave it alone.

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: December 08, 2018, 06:12:26 am
content: Well thanks for the reply's, can I ask what the risk is when using this stuff with smd parts? Is it going to cause corrosion over time? The stuff said it will solder with a match on the label I tried to spread it on two pieces of 6ga wire and use a butane heat gun to get it soldering I ended up having to use the iron in the end, so not as impressive as there pitch, I will stick with my leaded silver bearing solder for most things but thought this stuff may work well for QFNs with a heat gun.