LED strip soldering splice code violation?

[Mr. Serious]

63/37 is known as "eutectic" point if I recall correctly. Something about the metallurgy allows for a precise melting point at that exact blend of tin and lead. Any other blend will melt and solidify slower, because the temperature will change by several degrees during the melting/freezing process. So, it's easier to use the solder with the 63/37 blend.

You can still use lead-based solder for electronics, but you can't sell the resulting product in the EU or in California. I don't think anybody yet knows if there is a non-lead solder that will perform as well over the long term.

 

[garbo]

60/40 was standard for electrical soldering, plumbing solder was usually 50/50. The higher the tin content (first number), the lower the melting point.
Of course, no more lead these days….

Thanks. I have used the lead free solder for plumbing in my own house and use my acetylene tank with a turbo torch and at least when the lead free plumbing solder came out ( maybe early 1980's ) thought it ran more then the lead solder. Wonder how the lead free solder for wires & electronics is . Will have to order some. Hopefully they make it with the five cores of rosin. My brother worked for the local Ultility company and they were supposed to stop using lead tamp in anchors years ago. Still use my Greenlee screw in lead anchor setting tool for 1/4" anchors. Can remember as a teenager going to my buddies garage and getting a pile of used lead from his plumber dad and being in a garage for a few hours making fresh & salt water fishing weights with the garage door closed. Never know that lead fumes were not good to breathe.

 

[Mr. Serious]

There are various mixtures of lead-free solder. I think the kind I used for electronics was called SAC. I had done some research at the time and thought that was the best one, but now I don't remember why. Lead-free solder melts at a higher temperature so you have to set your soldering iron higher and make sure to solder quickly and not overheat the components.

 

[gadfly56]

63/37 is known as "eutectic" point if I recall correctly. Something about the metallurgy allows for a precise melting point at that exact blend of tin and lead. Any other blend will melt and solidify slower, because the temperature will change by several degrees during the melting/freezing process. So, it's easier to use the solder with the 63/37 blend.

You can still use lead-based solder for electronics, but you can't sell the resulting product in the EU or in California. I don't think anybody yet knows if there is a non-lead solder that will perform as well over the long term.

The eutectic point is the lowest melting point for a multi-component alloy. Usually, it's just a binary mixture like lead/tin. If you graph the melting point on the y axis versus composition on the x axis, lead on the left and tin on the right, the curve is basically a "V" with the bottom of the "V" at the lowest melting temperature.

 

[Mr. Serious]

OK, I see the eutectic point has the lowest melting temperature, but don't the two gray areas just to the right and left of the eutectic point correspond to states with partial liquid and partial solid? I've never had a metallurgy class so I don't understand the theory behind it, but to me it looks like your diagram shows liquid plus some amount of solid lead on the left, and liquid plus some amount of solid tin on the right. So if you get too far away from the eutectic point, you have a whole range of temperatures at which you have partial liquid and partial solid.

 

[gadfly56]

OK, I see the eutectic point has the lowest melting temperature, but don't the two gray areas just to the right and left of the eutectic point correspond to states with partial liquid and partial solid? I've never had a metallurgy class so I don't understand the theory behind it, but to me it looks like your diagram shows liquid plus some amount of solid lead on the left, and liquid plus some amount of solid tin on the right. So if you get too far away from the eutectic point, you have a whole range of temperatures at which you have partial liquid and partial solid.

Yep. If you have time and brain cells to kill, watch this.

alpha lead in alloys - Search Videos

www.bing.com

 

[PaulMmn]

One of the issues with non-lead solders is the early versions grew metal 'whiskers' that short circuited circuit boards. I don't know if they fixed that problem, or if a coating of the circuit board seals the solder so the whiskers don't grow.

 

[PaulMmn]

Yep. If you have time and brain cells to kill, watch this.

alpha lead in alloys - Search Videos

www.bing.com

Interesting discussion, but more than I really need to know about solder! Just pick the 63/37 blend for the optimal solder experience!
Which is, if I understood any of that video, that the Eutectic solder blend solidifies directly, without going through a 'slushy' phase, with 'lumps' of solid lead or tin as the solder solidifies.
In electronics, 60/40 has been the 'standard' for years. I wonder if 63/37 is harder to mix than 60/40?
Plumbers use 50/50 (?), probably more from tradition than anything else!
Question now is-- do any of these mixture result in a stronger joint?

 

[garbo]

One of the issues with non-lead solders is the early versions grew metal 'whiskers' that short circuited circuit boards. I don't know if they fixed that problem, or if a coating of the circuit board seals the solder so the whiskers don't grow.

I have heard about growing whiskers that shorted circuit boards but never know

 

[garbo]

Oops part two. Never know the growing whiskers appear to be a problem with only lead free solder. Starting maybe 10 years ago all of the replacement boards from Danfoss had coated boards that wonder if the coating prevented whiskers from growing. I preferred the coated boards especially in damp drive locations. Was lucky enough to see boards going thru think they called it a wave soldering station. The boards traveled thru a molten solder bath. This was in an Allen Bradley factory where I attended a week drive class.

 

[LarryFine]

Oops part two.

You can edit an oops post.

 

[PaulMmn]

Oops part two. Never know the growing whiskers appear to be a problem with only lead free solder. Starting maybe 10 years ago all of the replacement boards from Danfoss had coated boards that wonder if the coating prevented whiskers from growing. I preferred the coated boards especially in damp drive locations. Was lucky enough to see boards going thru think they called it a wave soldering station. The boards traveled thru a molten solder bath. This was in an Allen Bradley factory where I attended a week drive class.

Was at a trade show and had the opportunity to watch modern (for 1972 era) automatic machinery-- rolls of resistors, capacitors, and a single IC (probably a 555), fed into a machine that made a composite tape of parts in a certain order. That roll then fed a machine that grabbed the components by the legs, bent them to shape, and stuffed them in a circuit board. Once the board was stuffed, we fed them into a wave soldering machine-- pre-heat, brush with flux, skim over a fountain of solder, then through a flux remover. Other than the fact that each stage was interrupted by a nice talk by a company spokesman, it took less than a minute to complete a circuit board.
Of course, back then it was probably standard lead-based solder. The board was a pulse generator, and still works!

 

[garbo]

Was at a trade show and had the opportunity to watch modern (for 1972 era) automatic machinery-- rolls of resistors, capacitors, and a single IC (probably a 555), fed into a machine that made a composite tape of parts in a certain order. That roll then fed a machine that grabbed the components by the legs, bent them to shape, and stuffed them in a circuit board. Once the board was stuffed, we fed them into a wave soldering machine-- pre-heat, brush with flux, skim over a fountain of solder, then through a flux remover. Other than the fact that each stage was interrupted by a nice talk by a company spokesman, it took less than a minute to complete a circuit board.
Of course, back then it was probably standard lead-based solder. The board was a pulse generator, and still works!

Good old 555 universal timer chip that is still being used. Back in the 1980's I purchased some 20 to maybe 30 page booklets that Radio Shack sold. One was for things you could build with the 555 chip. I used an Omron universal timer to provide a 30 minute time delay off for the central vac that I installed in my house. Kids would plug in one of the hoses and forget to remove the hose. One of these days I should take this timer apart to see if it uses the 555 chip.

 

[Mr. Serious]

I should take this timer apart to see if it uses the 555 chip.

Probably either that or the CD4541B if they used an RC oscillator. IIRC the 4541 is what I found when I took apart a newer toaster. Older toasters just used a bimetallic strip, no electronics.

If Omron wanted to use a crystal oscillator for better accuracy, then they probably used an IC with a digital clock input like the 74HC292 or '294. Or a microcontroller. These days a small 8-bit microcontroller is cheaper than a standard logic chip.

 

[garbo]

Correct. Lead solder is still available in the US. But it’s no longer legal to use for plumbing applications.
The EU banned it completely in 2018.

You would think that since solder containing lead was banned for soldering copper water lines back in the 1980's they would have banned all lead. While working at a large slaughter house back in the 197O' s Weights & Measures department came to check weights for the wheeled trolleys that had a hanging hook to hang meat. Most were short by several ounces on the 7 or 7.5 pounds they had scale on kill floor was programmed for to print out weight tickets. Company attempted to say that is not a finally weight because the hours a side of beef hung in huge meat chill box it lost weight from water evaporation then some trimming of excess fat. They ended up making home made 1/2" diameter rivets made from.lead of different weights to install in one or two of the 4 holes in trolley wheel. Every time the trolleys came back they had to be sanitized by dipping them in hot water with a disinfectant. Was surprised that they got away with using pure lead.

 

[Mr. Serious]

You would think that since solder containing lead was banned for soldering copper water lines back in the 1980's they would have banned all lead.

Lead still makes a longer lasting roof flashing than any other material in common use. When I lived in Stillwater, OK, about a decade ago there was a roofing company there that did lead flashings around pipes penetrating the roof. I think they're still offering that.

I think in most states they can also still use lead for wheel balancing weights on cars, but more of it gets into the environment from that because sometimes the wheel weights fall off.