Fire Metall Eutectic Solder
Fire Metall is Norwegian for "Four Metal". This is a reference to the basic makeup of the solder -Tin/Lead/Silver/Copper.
It was designed by a diyAudio member Einric (an electronics technician with 20 years experience and also passionate DIYer), to be the perfect solder for do-it-yourself hobbyists to use for their audio projects.
- 0.020" (0.5mm) diameter
- 3% MAR core
- Made in the USA
- 4oz (113g) spool
A eutectic (melts and solidifies at one temperature) solder blend of four metals. Tin and lead have been used for years to make the solder that many people are familiar with.
Traditionally eutectic tin/lead solder is a 63/37% blend. High tech eutectic solder has 2% of silver integrated into the blend. This silver additive provides additional mechanical strength to the joint.
I have chosen to add a proprietary amount of copper to the mix. The copper additive provides resistance to thermal cycle fatigue, improves the wetting process of the joint and improves soldering iron tip life. To further improve the wetting of the solder joint I have chosen a Mildly Active Rosin (MAR) core. This helps to clean the joint surfaces during the soldering process.
Internal testing has shown that the melting point of the solder is approximately 330F/165C. The eutectic nature of the solder is very handy for beginners, it reduces the chances of a "cold solder joint". The low melting point reduces the time spent on each joint.
The smaller (0.020") diameter has multiple benefits;
- Lower thermal mass at the joint.
- Greater control over the amount of solder being applied to the joint.
- Ease of application in tightly packed circuits.
I do all my soldering at 650F (343C) with a 3/16" (4.8mm) chisel tip. It works well for 90% of everything I do. I solder in a 3 second cadence, "On One Thousand, Heat One Thousand, Off One Thousand". If I can't get the joint filled in that time then I wait for the joint to cool and try again, this helps to prevent lifting any PCB traces.
I recommend that all boards be cleaned after soldering is completed. Even "no clean" solder should have the boards cleaned because dust can build up on the rosin residue. Over time you can build up enough dust to start collecting trace moisture from the air. This build up can create a noisy circuit under certain circumstances. Rubbing alcohol or nail polish remover and an old tooth brush works really well at cleaning the boards.
For some great soldering how-to videos, we recommend having a look at the great videos in Dave Jones' EEV Blog Soldering Playlist .
At home Einric uses a Hakko FX-888D which is an excellent all-round choice for any hobbyist. At work he uses a Pace PRC-2000 (which can sometimes be found cheaper on eBay, and being industrial equipment will serve you for a lifetime).
As a longtime audio hobbyist this particular product is new to me, having used numerous solder types previously including another popular brand eutectic. So far I’m finding FIRE-METALL is terrific for wiring passive crossovers, as well as for terminating speaker cables and interconnects. It has excellent joint strength and looks great too in case the finished work will be exposed. I expect to see the same desirable results with PCBs though I rarely dabble with them.
When experimenting with eutectic solder for the first time it can be tricky to command, but once the correct temp is dialed in your project(s) will thank you and your patience will be rewarded.
(With their rebuild still in progress, the first-order crossovers depicted belong to a pair of ‘70’s era Rectilinear XI’s… a ported 10” 2-way bookshelf design employing the ever popular 2” paper cone tweeter with phenolic-ring surround. Only the sand-cast resistor being kept for posterity, all else upgraded. FIRE-METALL used throughout to optimize performance and longevity.)
Get some of this and make you diy easier.
Absolutely love this stuff. The smaller diameter and low melt point make it easy to create nice looking solder joints. Also a breeze to reflow and desolder.
This stuff is magic. Thank goodness I had ordered it before soldering my first SMDs in Wayne’s 2018BA line stage. Other than when soldering heat sinks or snap-in caps and similar big pieces, I can’t see returning to other solders.
Wonderful product. Great flow. Thanks
Easy to flow and professional looking results without fail. It's my first time using this type of solder, and you will be very pleased, even if you are a novice tech.
I've even dug old boards and components up out of the basement and completed the assembly just for fun! Wouldn't have done that in the past.
Nice flow into the wire, sets almost instantly.
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