dagabu Posted October 3, 2011 Posted October 3, 2011 I snagged a quart from Duda, I will sell a couple ounces to anyone that wants some, I just have to look at the postal requirements first. -dag
Mumbles Posted October 4, 2011 Posted October 4, 2011 What concentration of phosphoric acid is needed? I'm sure it's similar, but you can get an approximately 35% solution for cleaning grout at Home Depot at least. According to the density given by the MSDS, it is about 35%. Is the full strength 85% stuff required? http://www.homedepot.com/buy/miracle-sealants/1-quart-fast-acting-phosphoric-acid-cleaner-14470.html
WSM Posted October 4, 2011 Posted October 4, 2011 What concentration of phosphoric acid is needed? I'm sure it's similar, but you can get an approximately 35% solution for cleaning grout at Home Depot at least. According to the density given by the MSDS, it is about 35%. Is the full strength 85% stuff required?http://www.homedepot...aner-14470.html I'm not certain. The phosphoric acid I used was purchased from a Chemistry Lab Supply Company over twenty years ago. I believe it was technical and not reagent grade. I suppose it was full strength but suspect the dilute acid would work just fine. A high percentage isn't required to act as a flux. The main concern are the other ingredients and if they would interfere with soldering. The full strength acid worked well and very quickly. The dilute acid should be tested. My best guess is it would work fine and, at worst, need to be exposed to the metals a little longer to work the same. If anyone tries the dilute acid, please report your experiences here. WSM
dagabu Posted October 4, 2011 Posted October 4, 2011 Interestingly enough, this is the same stuff that changes rust to an inert coating. The quart from Duda will go to treating some rust I have and an ounce will go to soldering nichrome. Thanks WSM! -dag
WSM Posted October 4, 2011 Posted October 4, 2011 Interestingly enough, this is the same stuff that changes rust to an inert coating. The quart from Duda will go to treating some rust I have and an ounce will go to soldering nichrome. Thanks WSM! -dag You're welcome, dag. It's also the main ingredient in "Lime-A-Way" which cleans lime scale and rust from bathroom porcelain surfaces. Have fun... WSM
Mumbles Posted October 5, 2011 Posted October 5, 2011 At least somewhat recently, Lime-a-way started using sulfamic acid instead of phosphoric.
WSM Posted October 5, 2011 Posted October 5, 2011 At least somewhat recently, Lime-a-way started using sulfamic acid instead of phosphoric. Well that's dissappointing. I wish they'd leave these things alone. Oh well... WSM
Mumbles Posted October 5, 2011 Posted October 5, 2011 Hey now, sulfamic acid has uses of it's own. It's not like phosphoric acid is now unobtainable. Actually, sulfamic acid works rather well for that matter.
mike_au Posted October 5, 2011 Posted October 5, 2011 Quite a few of the rust treatment products I have seen are reasonably high concentrations of phosphoric acid. It's also used in parkerizing metals, so gun shops might carry it (this would probably be more pure than the rust converter stuff). I've also heard of something called "rose flux" being used to solder to nichrome. I've never found any or even been able to find out what is in it (I got the impression it's an old product) but maybe some welding supply places might have it. The other option (if you are joining to wires rather than PCBs) is a wirewrapping tool. With a bit of practice you can get a really good connection. I've torture tested my matches made this way and even after being quite roughly treated and stored for several months they all fired perfectly. Wirewrapping is rather tedious though, I will be moving to a PCB based match before too long.
Nessalco Posted October 5, 2011 Posted October 5, 2011 I've also heard of something called "rose flux" being used to solder to nichrome. I've never found any or even been able to find out what is in it (I got the impression it's an old product) but maybe some welding supply places might have it. Rose was a brand name of soldering flux. I haven't seen it around for years, though I have a tiny bit left in an old can. Any acid-based soldering flux works well, and I use silver solder for nichrome. I used to solder a lot of high-current igniters for rocketry, and these products work very well, with no corrosion after several years of storage. The only drawback is that the finished product needs to be thoroughly cleaned before any pyrogen dips. To clean I swish in acetone then Dawn dishwashing liquid in water. For ematches, I just buy heads by the 1000 from ODA, and use standard rosin-core solder.. Lazy, I guess. Kevin
oldmanbeefjerky Posted October 5, 2011 Author Posted October 5, 2011 well, ill have a look see for phosphoric acid. i swear my local home hardware store stocks it in solid or goo form 30% acid, mixed with some other chemical, i think is resin. its sold in the paint aisle, alongside paint thinners, strippers and a number of resin related products. come to think of it, it might be resin remover. anyway, i can get a very small tin of it for very little, so ill give it a shot.
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