Thomas
I have worked with varnished wire, and have a couple of spools of it even. When it is stiff, it is not the same type of stiff as when you have hardened rubber insulation. If the cotton has actually broken down enough, the varnish still holds it around the wire, but the cotton still breaks when the wire is bent- I have had to repair a number of "Fungicidal Varnish Applied" units because the cotton insulation was weak and breaking.
In the case of a Radiola, I would not hold much hope in applying acetone. It may be worth trying on one wire, but if the inner insulation turns to gooey mush, you have only lost the one wire.
Other than sleeving the wire coming out of the transformers, for the sake of safety, the only way to reliably make the repair is to replace the wire if it breaks wwhile being moved, or just do not touch it.
:Wires are often varnished. You can soak them with acetone (nail polish remover). This may soften them. Do not turn on the radio until the acetone has dried, or you may explode the radio.
:
:Thomas
I have used acetone on many cloth wires, though, with no problems. You soak a cloth and rub the acetone onto the wire liberally. If you were to pour the acetone onto the radio, you'd ruin things, but using a cloth gives you control. Keep the bottle away from all plastic items and put it in a place where it cannot dump over. Perhaps work on softening the wires next to your kitchen sink. Put the bottle down in the sink, where if it tips over, it will simply run down the drain.
One note: if you are softening cloth covered rubber insulated wires, the cloth may still break even after the varnish has been softened if the rubber in the center is extremely hard. Bending the wire with hard rubber will cause the rubber to crack and form sharp edges. It will tear through the old cloth. If your wire is really bad, www.tubesandmore.com sells several types and many colors of cloth covered wire that will look pretty good in your radio. Unfortunately they do not sell wire with tracers (stripe of color through another color).
Another note: cotton never stiffens. It doesn't. Never did, never will. If you have a wire that is double cloth insulated, the only way it will stiffen is if there is some agent in the cloth that has stiffened, such as varnish. This agent may be softened with acetone.
Acetone will only momentarily soften a wire. After the solvent dries, the wire will stiffen again. This is only a method of softening the wire so that it may be moved for one reason or another. It is not a cure-all. There is no real easy cure for stiff wires. They must be replaced if long term flexibility is desired. As for acetone ruining parts in a radio, it will soften rubber and wax and will remove paint. It can severely dry out rubber drive wheels in phonographs. It is excellent for removing oil from the rubber wheels, but should only be used momentarily. The wheels should never be soaked in acetone. It has no affect on bakelite or phenolic wafer tube sockets. It has no great affect on cardboard. It will ruin coils, as they are insulated with enamel, which is soluable in acetone. It will take color markings off of resistors and condensers. It will ruin plastic dials and scales and windows. It will take the enamel numbers off of glass dials and scales. It will take the painted logos and lettering off of tubes. It will take the finish off of the radio's cabinet if the cabinet is painted or varnished. Plastic knobs that are not bakelite may be ruined by acetone. It should never be poured into volume controls or other such controls, transformers, RF transformer cans, etc. It will ruin speakers if allowed near the voice coil, though sometimes it works as an excellent glue loosener around the edge of the cone, if you need to take the cone out for some emergency repair (internal voice coil issues, shifted magnet, etc.), and wish to re-use the cone.
Thomas
:Acetone is a powerful solvent, considering the age of the radio, it may do much more harm than good so experimenting with a sacrificial piece of wire is just prudent. There is not any real practical way to "restore" the flex in the wire, as it is likely to be a hardened natural rubber, or cotton/double cotton insulation that is just deteriorated and is what is actually stiffening things up.
:
:I have worked with varnished wire, and have a couple of spools of it even. When it is stiff, it is not the same type of stiff as when you have hardened rubber insulation. If the cotton has actually broken down enough, the varnish still holds it around the wire, but the cotton still breaks when the wire is bent- I have had to repair a number of "Fungicidal Varnish Applied" units because the cotton insulation was weak and breaking.
:
:In the case of a Radiola, I would not hold much hope in applying acetone. It may be worth trying on one wire, but if the inner insulation turns to gooey mush, you have only lost the one wire.
:
:Other than sleeving the wire coming out of the transformers, for the sake of safety, the only way to reliably make the repair is to replace the wire if it breaks wwhile being moved, or just do not touch it.
:
:
::Wires are often varnished. You can soak them with acetone (nail polish remover). This may soften them. Do not turn on the radio until the acetone has dried, or you may explode the radio.
::
::Thomas
I still stand by my points of leaving the wires alone if possible, replacement if the insulation is breaking, or sleeving. If the cotton is breaking on a cloth covered rubber wire, the underlying rubber is just as dry rotted as the cotton.
Remember, these radio are old, and have some inherent hazards in them, one of them being fire from electrical sources. I would discourage the use of any solvent for that purpose because it's use will reduce the integrity of the insulation more than you might realize.
:Since we are talking about cloth covered wires, acetone won't do any harm. It has no affect on cotton. The rubber insulation inside may be softened, but unless you soak it for days, it isn't exactly going to ooze out of the cloth. Many of the older radios use purely cloth insulation inside the radio, perhaps double layer cloth. I wouldn't use acetone on rubber wires (no cloth). This will create a mush. I guess it is a good idea to test first, as always, but with the cloth wires we were talking about, it will not harm them. The only cloth wires you really have to worry about are those produced after WWII. Some manufacturers experimented with synthetic cloth. You may note that these wires will still be bright in color even after all of these years, and the cloth will melt when it is touched by a soldering iron.
:
:I have used acetone on many cloth wires, though, with no problems. You soak a cloth and rub the acetone onto the wire liberally. If you were to pour the acetone onto the radio, you'd ruin things, but using a cloth gives you control. Keep the bottle away from all plastic items and put it in a place where it cannot dump over. Perhaps work on softening the wires next to your kitchen sink. Put the bottle down in the sink, where if it tips over, it will simply run down the drain.
:
:One note: if you are softening cloth covered rubber insulated wires, the cloth may still break even after the varnish has been softened if the rubber in the center is extremely hard. Bending the wire with hard rubber will cause the rubber to crack and form sharp edges. It will tear through the old cloth. If your wire is really bad, www.tubesandmore.com sells several types and many colors of cloth covered wire that will look pretty good in your radio. Unfortunately they do not sell wire with tracers (stripe of color through another color).
:
:Another note: cotton never stiffens. It doesn't. Never did, never will. If you have a wire that is double cloth insulated, the only way it will stiffen is if there is some agent in the cloth that has stiffened, such as varnish. This agent may be softened with acetone.
:
:Acetone will only momentarily soften a wire. After the solvent dries, the wire will stiffen again. This is only a method of softening the wire so that it may be moved for one reason or another. It is not a cure-all. There is no real easy cure for stiff wires. They must be replaced if long term flexibility is desired. As for acetone ruining parts in a radio, it will soften rubber and wax and will remove paint. It can severely dry out rubber drive wheels in phonographs. It is excellent for removing oil from the rubber wheels, but should only be used momentarily. The wheels should never be soaked in acetone. It has no affect on bakelite or phenolic wafer tube sockets. It has no great affect on cardboard. It will ruin coils, as they are insulated with enamel, which is soluable in acetone. It will take color markings off of resistors and condensers. It will ruin plastic dials and scales and windows. It will take the enamel numbers off of glass dials and scales. It will take the painted logos and lettering off of tubes. It will take the finish off of the radio's cabinet if the cabinet is painted or varnished. Plastic knobs that are not bakelite may be ruined by acetone. It should never be poured into volume controls or other such controls, transformers, RF transformer cans, etc. It will ruin speakers if allowed near the voice coil, though sometimes it works as an excellent glue loosener around the edge of the cone, if you need to take the cone out for some emergency repair (internal voice coil issues, shifted magnet, etc.), and wish to re-use the cone.
:
:
:Thomas
:
::Acetone is a powerful solvent, considering the age of the radio, it may do much more harm than good so experimenting with a sacrificial piece of wire is just prudent. There is not any real practical way to "restore" the flex in the wire, as it is likely to be a hardened natural rubber, or cotton/double cotton insulation that is just deteriorated and is what is actually stiffening things up.
::
::I have worked with varnished wire, and have a couple of spools of it even. When it is stiff, it is not the same type of stiff as when you have hardened rubber insulation. If the cotton has actually broken down enough, the varnish still holds it around the wire, but the cotton still breaks when the wire is bent- I have had to repair a number of "Fungicidal Varnish Applied" units because the cotton insulation was weak and breaking.
::
::In the case of a Radiola, I would not hold much hope in applying acetone. It may be worth trying on one wire, but if the inner insulation turns to gooey mush, you have only lost the one wire.
::
::Other than sleeving the wire coming out of the transformers, for the sake of safety, the only way to reliably make the repair is to replace the wire if it breaks wwhile being moved, or just do not touch it.
::
::
:::Wires are often varnished. You can soak them with acetone (nail polish remover). This may soften them. Do not turn on the radio until the acetone has dried, or you may explode the radio.
:::
:::Thomas
Unless you are completely butterfingers, you are not likely to damage anything else if you exercize caution. Keep the bottle away from the radio and moisten a rag with the acetone. Use the rag to distribute the acetone over the wire. Have fun. See what happens.
T.D.
There are too many ways that wiring can short if the insulation is compromised and it is therfore not a safe suggestion to soften dry rotted rubber because lives and property are potentially at stake, and most insurance companies are not likely to cover anything that goes horribly wrong. I have seen some products that were made of the same materials used in the manufacture of wire insulation that once softened by exposure to some solvent continue to degrade to a gooey mush.
You also have to understand that there are a number of young people who are reading these posts, and acetone being what it is, is not something that young people should handle without significant safety precautions.
We will just have to disagree on the matter and let it rest because I am not going to be swayed in my position about something that I see as not safe, and potentially deliterious to something not intended to be exposed and those cautions so far have been overlooked. You can disagree, and we can do so with civility, but about the only finishes other than metal plating that are not harmed by acetone are a few formulations of heat cured powdercoat. Not to mention the potential fire hazard presented from open pilot lights, or open gas flames from a water heater or furnace, or the rare but real potential for spontaneous combustion of rags.
This is no flame, and no aspersions are being cast against you. There is just a point where in a matter such as this that you just need to let it go, because I know from my own significant experience with tube gear that people are going to disagree on some various points on restorations, and some of them quite significant. Remember your audience, and understand that not everyone is going to be paying full attention if they may try it.
:True that. ....But if you +must+ move a wire (remove a transformer, part, etc.), you either need to make the wire flex somehow or replace the wire. Acetone will ruin many things, and so you must use extreme care when using it, but it does not deteriorate cotton. There is a chance that the rotten rubber underneath the cotton, if rubber is used, will tear the cotton, but it is also highly likely that if nothing is done to this stiff wire that it will crack anyway. So, if you want to try to save a wire for some reason, you have to try something, and acetone is just what you need to soften varnish. If the wire does not have rubber in the center, and is simply varnished, then the acetone will do the trick quite well, as varnish is easily softened with acetone.
:
:Unless you are completely butterfingers, you are not likely to damage anything else if you exercize caution. Keep the bottle away from the radio and moisten a rag with the acetone. Use the rag to distribute the acetone over the wire. Have fun. See what happens.
:
:T.D.