diy solderpot, what metal doesn't dissolve? - Page 1
Forum section: electronics / projects

author: zappedy
author_rank: Regular Contributor
timestamp: January 18, 2017, 05:29:06 pm
content: I know tin dissolves a lot of metals, what should I use for an electric solder pot? Stainless steel? I might want to use some special alloys such as Chipquik if that matters, so I will use swappable pots to avoid alloy contamination.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 18, 2017, 05:36:35 pm
content: Stainless steal has several components. At least nickle can dissolve.To be on the sure side, I would use ceramic material like porcelain, alumina or maybe high temperature resistant glass. Small porcelain crucibles are relatively cheap available at the chemicals supplies - just look for the standard sizes.

author: zappedy
author_rank: Regular Contributor
timestamp: January 18, 2017, 11:12:32 pm
content: Too bad, would rather avoid porcelain for fear of it cracking if it has thin enough walls to only need a tiny heating element.What do commercial solder pots use?

author: Ian.M
author_rank: Super Contributor
timestamp: January 18, 2017, 11:41:17 pm
content: You could probably get away with oiled cast iron - heat till its blued, wipe with linseed oil and bake out, repeating till there's a decent layer of blacking built up. Iron can dissolve, but if its blacked, it will only dissolve at scratches that are large enough for the solder to wet, and if you dump it out and re-black it occasionally, that can be controlled.Remember: Iron plating on bits is used to make them resistant to solder erosion.

author: bpiphany
author_rank: Regular Contributor
timestamp: January 20, 2017, 07:10:29 pm
content: Try thishttp://www.emsnow.com/cnt/files/White%20Papers/speedLiquidTinCorrosionLeadFreeWave.pdfEbay lead free pots seem to be titanium or titanium coated (titanium nitride?). According to that paper cast iron can be a good alternative as well.And of course there are the more exotic choices..http://www.pyromatics.com/solder-pots.htm

author: calexanian
author_rank: Super Contributor
timestamp: January 21, 2017, 03:22:40 am
content: Passivated stainless steel works. Generally the chrome is hardened at the surface. What you have to worry about really is the flux. That will eat everything. Plain old steel works as well, but will eat away eventually.

author: zappedy
author_rank: Regular Contributor
timestamp: January 22, 2017, 07:49:40 pm
content: Quote from: bpiphany on January 20, 2017, 07:10:29 pmGreat link! Do you know of a similar white paper on leaded solder?All the suggestions in this thread were great; I did start thinking though that it needs to be very cheap to be worthwhile/interesting as diy, so I got a tiny 50 cent porcelain muffin cup and will report back if it works.I guess titanium braid/strips would be a decent choice for a non-dissolving tip scrape to keep in the solder.

author: zappedy
author_rank: Regular Contributor
timestamp: January 23, 2017, 01:57:42 pm
content: By the way, would high temperature silicone work, for leaded solder which has a lower melting point that lead free?

author: nanofrog
author_rank: Super Contributor
timestamp: January 23, 2017, 02:16:04 pm
content: Quote from: zappedy on January 23, 2017, 01:57:42 pmNot really, as the working temp of leaded alloys is still higher than silicone can handle constantly (i.e. temp specs on rubbers have a time duration).As per ceramic, think crucible (they also make them in graphite).

author: bpiphany
author_rank: Regular Contributor
timestamp: January 25, 2017, 02:08:07 pm
content: Quote from: zappedy on January 22, 2017, 07:49:40 pmNo idea, that one was among the first I found on googling for lead free solder pot materials..I have an ebay solder pot myself. It should be of solid titanium, and looks like it. I don't know if it is like with aluminum that the oxide is the protective part, or if the titanium itself doesn't dissolve.

author: zappedy
author_rank: Regular Contributor
timestamp: January 25, 2017, 04:12:48 pm
content: Wtf, less than $15,including shipping, from the communists! DIY is dead...From your link it looks like it is the titanium itself.

author: Ian.M
author_rank: Super Contributor
timestamp: January 25, 2017, 04:33:24 pm
content: Its the oxide. Titanium forms an even more tenacious oxide film than Aluminium does. It also retains its strength up to 430 °C which means the oxide film isn't easily disrupted by the metal deforming.Here's theSn-Ti Phase Diagram, which indicates that if a Titanium part breaks exposing a fresh surface while fully immersed (excluding Oxygen) in Tin containing molten solder above 232°C, you can expect significant corrosion of the broken surface.