I don't have an answer for your but I'm puzzled by the responses. I thought the learned opinion on the forums a while back was that crimped connections were better than soldered connections. In this case, crimped connections with non-corrosive goo and adhesive shrink wrap would be the bestest!
Hope this doesn't cause a firestorm of debate around your project.
Based on my experience I would say all else being equal, nothing beats a good solder joint. Of course the solder joint has to be done properly. At least an inch of overlap between the wires to be joined, an adequate and even application of solder, and complete removal of flux residue and other contaminants from the area the shrink wrap and/or other insulating material will be placed.
Not sure I understand the reason for using food grade silicone sealant but I've also used silicon inside of heat shrink tubing for splices that needed to be water "safe". For "smallish" gauge wires you can get plastic crimp connectors. They contain a small vial of silicon and when you crimp the connector to make the connection the vial breaks and seals the connection. I haven't seen them for wires bigger then 18 gauge though and won't be useful in this case.
The food grade silicone sealant does not contain acetic acid.
Acid or basic conditions set up corrosion around electrical connections. Just look at the battery in your car. It is lead acid, so the cables become a mess. It is all about providing unwanted ions. Even acid core solder is a problem. Regular silicone used chlorine as a catalyst for setting and that is ionic (thus the food grade is thought as best). I am not sure where the acetic acid comes in (maybe in food grade as acetic acid is equivalent to vinegar). I do find cleaning copper circuit board with alcohol a corrosion problem as that too is a slight acid (so I use soap and water).
There is a real perception problem here with recommending any particular silicon as superior in this context. Why so? The manufacturers have taylored proprietary formulations. There are regular, food-safe, and fish-safe. Some 'regular' compounds have fungicides in it. That may not be safe for food or fish; but good for a wire connection. Furthermore, it seems most have moved entirely away from cholorine and into acetic acid for setting the RTV (room temperature vulcanization) Silicon sealants. Thus, this is a huge tempest-in-teapot. In this context, any silicon is likely to work well. If you have doubts, use hot glue (and don't ask me what's in it). A soft epoxy might be the truly best alternative as an inert, water tight sealant.
And, if the wires to be connected are going to heat up enough to potentially melt normal solder, a crimped or mechanically connected wire is better. Just look at all the heavy wiring inside your home fuse box. No soldering there - all mechanical. Sometimes, silver solder is used to tolerate a higher temperature.
In older homes, all the wiring in the walls was soldered and wrapped with tape; ceramic knobs and tubes kept the wires away from wood.
Now all connections are required to be made inside an electrical box in order to prevent fire. Also, the boxes allow one to open and repair failed connections as nearly all failures of wire are at the connections.
Old school (circa 1950s) technique required that all solder joints first be constructed as a good mechanical joint, and only then be soldered.
In other words, techniques are evolving as we speak. Use common sense and try to make the connections both durable and repairable.
...And, if the wires to be connected are going to heat up enough to potentially melt normal solder, a crimped or mechanically connected wire is better. Just look at all the heavy wiring inside your home fuse box. No soldering there - all mechanical. Sometimes, silver solder is used to tolerate a higher temperature...
FYI - For high amperage electrical connections, the mechanical connections need to be torqued to a specified tightness or the connection will get warm or hot!
"Tight" is not good enough. Needs to be "tighter". They typically specify to tighten in "inch pounds". 1 foot pound = 12 inch pounds.
FYI - For high amperage electrical connections, the mechanical connections need to be torqued to a specified tightness or the connection will get warm or hot!
"Tight" is not good enough. Needs to be "tighter". They typically specify to tighten in "inch pounds". 1 foot pound = 12 inch pounds.
Not that is relevant to this thread, but since you brought it up.
Several years ago I attended a licensing preparation seminar for the NEC (National Electrical Code) and the speaker was Tom Henry's son. Both Tom Henry and his son are experts in the NEC. During the seminar, he told the class that he is often called to testify as an expert witness in cases that involve both fire and death resulting from faulty wiring. He also said that his main testimony often consisted of the hazards of not torquing electrical devices to the manufacturers specifications, at which point it is basically a shut case with the installer being liable for neglect, providing the installer did not properly torque the electrical devices.
Old school (circa 1950s) technique required that all solder joints first be constructed as a good mechanical joint, and only then be soldered.
This is still good advice - if it is a serious connection, I usually sparse-wrap with some finer tinned copper wire, a number of turns along the overlap, and then solder the lot.
If you do this to stripped, but _not_ tinned multi-strands, you can get a more circular end result.
Ensures nothing moves as the solder cools, and gives some ribs for that marine grade heatshrink to hold onto.
Comments
Based on my experience I would say all else being equal, nothing beats a good solder joint. Of course the solder joint has to be done properly. At least an inch of overlap between the wires to be joined, an adequate and even application of solder, and complete removal of flux residue and other contaminants from the area the shrink wrap and/or other insulating material will be placed.
The food grade silicone sealant does not contain acetic acid.
There is a real perception problem here with recommending any particular silicon as superior in this context. Why so? The manufacturers have taylored proprietary formulations. There are regular, food-safe, and fish-safe. Some 'regular' compounds have fungicides in it. That may not be safe for food or fish; but good for a wire connection. Furthermore, it seems most have moved entirely away from cholorine and into acetic acid for setting the RTV (room temperature vulcanization) Silicon sealants. Thus, this is a huge tempest-in-teapot. In this context, any silicon is likely to work well. If you have doubts, use hot glue (and don't ask me what's in it). A soft epoxy might be the truly best alternative as an inert, water tight sealant.
And, if the wires to be connected are going to heat up enough to potentially melt normal solder, a crimped or mechanically connected wire is better. Just look at all the heavy wiring inside your home fuse box. No soldering there - all mechanical. Sometimes, silver solder is used to tolerate a higher temperature.
In older homes, all the wiring in the walls was soldered and wrapped with tape; ceramic knobs and tubes kept the wires away from wood.
Now all connections are required to be made inside an electrical box in order to prevent fire. Also, the boxes allow one to open and repair failed connections as nearly all failures of wire are at the connections.
Old school (circa 1950s) technique required that all solder joints first be constructed as a good mechanical joint, and only then be soldered.
In other words, techniques are evolving as we speak. Use common sense and try to make the connections both durable and repairable.
FYI - For high amperage electrical connections, the mechanical connections need to be torqued to a specified tightness or the connection will get warm or hot!
"Tight" is not good enough. Needs to be "tighter". They typically specify to tighten in "inch pounds". 1 foot pound = 12 inch pounds.
Not that is relevant to this thread, but since you brought it up.
Several years ago I attended a licensing preparation seminar for the NEC (National Electrical Code) and the speaker was Tom Henry's son. Both Tom Henry and his son are experts in the NEC. During the seminar, he told the class that he is often called to testify as an expert witness in cases that involve both fire and death resulting from faulty wiring. He also said that his main testimony often consisted of the hazards of not torquing electrical devices to the manufacturers specifications, at which point it is basically a shut case with the installer being liable for neglect, providing the installer did not properly torque the electrical devices.
Bruce
This is still good advice - if it is a serious connection, I usually sparse-wrap with some finer tinned copper wire, a number of turns along the overlap, and then solder the lot.
If you do this to stripped, but _not_ tinned multi-strands, you can get a more circular end result.
Ensures nothing moves as the solder cools, and gives some ribs for that marine grade heatshrink to hold onto.