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Lead Free Solder with MODEL FM-88K Elenco Autoscan Radio Soldering Kit

I soldered this FM-88K w/ Lead Free Solder

I got to try lead free solder included with the Elenco FM-88K radio kit & it was a bit more challenging to use

Lead Free solder requires higher temperatures, long ago adopted by electronics manufactures of ROHS compliant devices to reduce hazardous substances like lead from consumer electronics, computers, smartphones, graphics cards, logic boards, toys & more. 

99.3% tin 0.7% Copper LF-99 Lead-Free Solder

In my current hobby setup, the Lead Free solder requires 540 F (282 C) in order to tin the tip of the 22w ESD soldering iron. As a 3D printing project the Prusa Mini FDM printer & design files from thingiverse I combined a 12v switching power supply from Amazon with a space 120mm PC fan & some white nylon zip ties to assembly the PETG parts, a fan shroud, base & connecting bolt, & later added a variable power controller. 

Hobby soldering setup on portable wood table

I place the parts to be soldered under the fan intake so that soldering smoke pulled away from the eyes & nose & face. During longer sessions I leave the garage door open for fresh air intake exchange. The setup also contains a wet sponge, brass wire flux cleaning holder, soldering flux container & articulating part holder with magnifying glass, on a portable wood table in the garage. 

Significantly & to my great honor & joy, I recently taught Meg how to solder via a HUE 1.0 RGB 2032 battery powered LED on a beautiful circuit board made in Sacramento California. I made a YouTube video about it you can see by click this Link ->  https://youtu.be/5NbRtvF1aPQ

Meg learning soldering w/ a Hue 1.0 RGB Kit 

I also soldered up a little red LED clock that failed within just a few hours of operation sadly. Here is a photo of it working / Instead of ordering another, I decided to try a handheld game kit // future posting or Youtube video. 

$10 Digital Red LED Clock (Soldering Kit) 

The electronics soldering kit radio I am listening to right now took about 2 hours to assemble & produce an auto scanning FM radio with 8 ohm 0.5 watt speaker thats powered by an include Rayovac 9V zinc manganese alkaline battery. This kit included LEAD Free Solder & inspired this post. Special thanks to Elenco for making soldering learning kits for children with Lead-Free solder! 

Previously I only used lead tin alloy solders & knew that lead free solder was harder to work with, requiring higher temperatures & does not flow or stick to soldering joints as well as leaded solder.

Kester NTE electronics solder I normally use
62% Tin, 36% Lead, 2% Silver 

Instead of using my NTE Kester tin, lead, silver electronics solder (Image Above), I gave the Tin Copper Lead-Free LF-99 solder a try & it did require higher temperatures and was harder to work with requiring the soldering iron to heat the parts for more time at a higher temperature setting. Given the way I sometimes hold the radio when using it, I am glad the solder points do not contain lead. I will likely 3D print a custom case for the FM-88 since the Prusa Mini available for a new project!

Hobby & Professional Soldering Experience

I have been soldering on & off for more than 25 years. Ken Schwarz taught me to use electronic solder to solder small DC circuits in the early 1990's. I work at Batteries + & sometimes use a very nice Hakko ESD 889 soldering station and a tab welder & nickel strips to build battery packs out of NiMH & NiCD battery cells, usually arranged into series of 2 or more cells to increase voltage. 

Most of the pack building involves using super glue with an aluminum alignment jig mounted into a v-cut wood block to line up the cells & glue them & we use a acetone based Satellite City super glue cure accelerator spray to set the glue quickly. Tab welding the sells together with thermal fuses & nickel strips using a pressure impact dual copper rod contact resistance welder puts a light weld between the end of the battery terminal & the nickel strip. 

Soldering usually only used during the final assembly stage when wires are soldered to nickel tabs to connect the batteries connectors to the cells inside. Depending on the geometry of the pack, PCV shrink wrap often applied to the cells to insulate & tightly bundle them. We use electrical tape to isolate wires from battery terminals & the nickel connecting strips & table & avoid sharp edges & route the wires so they wire insulation will not be damaged on a sharp edge. 

I take care not to breath the soldering smoke since the solder we use a 60% Tin 40% Lead alloy that melts nicely at lower temperatures & sticks to cleaned copper wire & clean nickel strips. We never solder to the end of the battery terminals as doing so can overheat the sealing gasket of the battery & increase the risk of electrolyte leaking. NiMH & NiCD batteries develop transient pressure differentials or increase & decrease in internal cell pressure when charging or discharging, so the sealing gasket integrity important. 

Battery pack cells can any size from SMC357 to CR2032 or similar coin or button cells, 1/2AAA to AA or Sub C or 5/4 or 2/3 or F sizes, depending on the application. Battery electric power tool batteries not available anymore due to the older age of the tool are often the types of tools that people have us custom rebuilt existing battery packs for. Sometimes we get a scientific research tool or law enforcement telemetry devices or HVAC system pack or exit sign pack thats so old the manufacture no longer supports customers with replacement batteries & the customer cannot find any online or any of good quality. Anton 16mm film camera batteries are another one we regularly rebuilt. Most of this equipment came out before lithium ion batteries were widely available or cost effective to use in COTS or consume off the shelf technology, i.e. common electronics. 

Energy Storage Fascinating / Chemical Batteries 

Batteries are electrochemical devices that store electrical energy as potential chemical energy. In a common alkaline or carbon primary battery this energy releases as a one time chemical reaction that proceeds to release electrons or electrical current into circuits in wall clocks, TV remotes, game console controllers, flashlights & other low drain applications. In heavily used smartphones & other daily use applications rechargeable batteries cost less as they can be recharged hundreds of times for several years typically, replacing many thousands of single use batteries in some applications. 

If you burn through a set of alkaline batteries in less than 2 weeks, consider getting some good quality low self discharge or pre-charged NiMH batteries & a charger & enough batteries to charge one set while your using the other so you can rotate between the two sets. Technically keeping NiMH & Lithium Ion batteries partially charged between 30% & 80% makes them last up to 10x longer, many thousands of discharge cycles & 10+ years of service. Toyota did this partial charging for longer cell life with NiMH batteries in their hybrid electric cars like the Toyota Prius lineup until a recent switch to a stronger robust type of lithium ion happened. 

I am interested in metals & energy & alloys & soldering, brazing, welding & melting metals with powerful torches in ceramic & graphite crucibles & moulds & metal casting & electro plating & all kinds of other fun a tiny hobby scales for fun learning & applying learning activities that students of all ages can enjoy. 

Do not just think about it. Go do it too. Meg & I are just about to go hiking right now, since I have to leave to work a little later. Be active & make it happen & believe in your self & have a can do attitude! Cheers friends & thanks for reading my blog! 



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