Weighing wire and possible discrepancies - Let's Discuss

[rhgwynn]

I have seen numerous threads where someone would do a rewind, based on the weight of wire cut off the bobbin. My first thought is this - well how do you account for the weight of the wax? My thinking is that you could boil it off - but no one mentions doing this. What if the pickup was lacquer potted? Do you soak the wire in thinner for a few hours? It seems to me that these things would definitely make a difference in the accuracy of the calculations, especially wax.

-Rob

[copperheadroads]

Weight a pickup before & after potting & come up with you own assumption .
I've never had a problem with wax so to pot in lacquer ,I don't see any reasoning

[rhgwynn]

Weight a pickup before & after potting & come up with you own assumption .
I've never had a problem with wax so to pot in lacquer ,I don't see any reasoning

Well if you are just dipping them, then no, it wont make a huge difference But if you are vacuum potting them, then you are getting a lot of coil penetration; there's just no way that you can fill in the gaps with wax or lacquer without adding weight. There's absolutely no reasoning or logic that can suggest otherwise. The only way you could even suggest that, would be if you are using a little non-scientific grade pot dealer's scale.

-Rob

[copperheadroads]

Well if you are just dipping them, then no, it wont make a huge difference But if you are vacuum potting them, then you are getting a lot of coil penetration; there's just no way that you can fill in the gaps with wax or lacquer without adding weight. There's absolutely no reasoning or logic that can suggest otherwise. The only way you could even suggest that, would be if you are using a little non-scientific grade pot dealer's scale.

-Rob

I dunk them in a wax pot & by the way that's all Leo Fender did .I don't think he ever considered using vacuum potting .
& by the way most makers work on successfully "flash potting" instead of trying to deeply penetrate the coils with wax ....... didn't you get the memo ?

[big_teee]

Well if you are just dipping them, then no, it wont make a huge difference But if you are vacuum potting them, then you are getting a lot of coil penetration; there's just no way that you can fill in the gaps with wax or lacquer without adding weight. There's absolutely no reasoning or logic that can suggest otherwise. The only way you could even suggest that, would be if you are using a little non-scientific grade pot dealer's scale.

-Rob

So what difference does it make?
weighing is just another tool a rough guide.
I like to mic the OD of the coil.
Most customers are going to tell you what specs they want the rewind, anyway.
Usually on a bridge, they say, "Can You wind it a Little Hotter than stock" ?

[rhgwynn]

I dunk them in a wax pot & by the way that's all Leo Fender did .I don't think he ever considered using vacuum potting .
& by the way most makers work on successfully "flash potting" instead of trying to deeply penetrate the coils with wax ....... didn't you get the memo ?

No need to be snobby about it man; I'm not here to discuss what Leo did or didnt do; nor do I care for "what most makers do". Your statement that "most" flash-pot holds no water. Did you personally query all the builders on their methods? Right.

So back on topic: Big Teee has a point. But sometimes a customer want it to be just like it was before it "broke". And you can't always locate the break. Hence the need to weigh the wire. But the potting material, whatever it may be, is going to have weight to it. There is no way around that. This thread is focused on how to get around that, and account for it without missing the mark when it comes to giving the customer a rewound pickup that meets their expectations.

-Rob

[big_teee]

No need to be snobby about it man; I'm not here to discuss what Leo did or didnt do; nor do I care for "what most makers do". Your statement that "most" flash-pot holds no water. Did you personally query all the builders on their methods? Right.

So back on topic: Big Teee has a point. But sometimes a customer want it to be just like it was before it "broke". And you can't always locate the break. Hence the need to weigh the wire. But the potting material, whatever it may be, is going to have weight to it. There is no way around that. This thread is focused on how to get around that, and account for it without missing the mark when it comes to giving the customer a rewound pickup that meets their expectations.

-Rob

Weight wouldn't be the whole story anyway.
More than likely your wire is going to be different diameter, and different ohms per foot.
So unless the wire replacing the original is the same, all bets are off!

[copperheadroads]

No need to be snobby about it man; I'm not here to discuss what Leo did or didnt do; nor do I care for "what most makers do". Your statement that "most" flash-pot holds no water. Did you personally query all the builders on their methods? Right.

So back on topic: Big Teee has a point. But sometimes a customer want it to be just like it was before it "broke". And you can't always locate the break. Hence the need to weigh the wire. But the potting material, whatever it may be, is going to have weight to it. There is no way around that. This thread is focused on how to get around that, and account for it without missing the mark when it comes to giving the customer a rewound pickup that meets their expectations.

-Rob

Like I Prevoiusly said ,weigh a pup with & without potting using a precise jewlers scale Not a common kitchen scale ,If your wanting similar to vacuuming then pot it long after the bubbles stop rising . repeat this a few times & you will have formula to work with .
I'm not getting snobby ,My statement "Most Flashpot" don't hold water ... That's fine & I bet you don't know why I would do this Instead of Vacuum potting a pup.........
Get your own results with your own research -It is quite rewarding
I

[David Schwab]

I sometimes weigh a bobbin before I do a rewind, if the coil is open. Then I zero out the scale with the empty bobbin, and wind to a point that I think should be good, and then weigh it again. So far is has worked well. I don't expect it to be exact though.

I don't think the wax adds too much, but I'm in the process of winding a 5 string Jazz bass pickup. I will weigh it before and after wax and report back.

[EDIT]

76 grams before wax.

78 grams after 10 minutes in the wax.

So it only added 2 grams.

[David King]

Copper has a great deal more mass than wax and the total quantity of wax is probably going to account for less than 1% of the total weigh of the coil. Wire diameter differences between one spool of wire and another are going to far outweigh the slight amount of wax you are concerned about here.

[rhgwynn]

I bet you don't know why I would do this Instead of Vacuum potting a pup.........

You think it has a stronger "musical quality" while still preventing feedback.... did I just blow your mind??
It's pretty subjective; some like it, some don't.

Thank you DS, for the contribution; I wonder now, what two grams would amount to - 200turns, maybe?

-Rob

[Stratz]

But sometimes a customer want it to be just like it was before it "broke". And you can't always locate the break. Hence the need to weigh the wire.
-Rob

Weighing the coil is just one of the many variables for rewinding a pickup to its original state .
It helps to have a large stock of wire types from different manufactures both vintage and modern since they can vary quite a bit. You will need a good quality micrometer and ohm meter to measure the DCR/1,000'.
An inductance meter is extremely helpful for logging pickup specs over a long period of time. An inductance meter can also tell you a lot about the materials used in the pickups construction.

It all comes down to experience in rewinding a large variety of pickups over many, many years.
Jason Lollar (to mention just one of many from this forum) is a very good example to set your sites on.

[Stratz]

I wonder now, what two grams would amount to - 200turns, maybe?

-Rob

One way to figure it out is to do it and log it.

[David Schwab]

I dunk them in a wax pot & by the way that's all Leo Fender did .I don't think he ever considered using vacuum potting .
& by the way most makers work on successfully "flash potting" instead of trying to deeply penetrate the coils with wax ....... didn't you get the memo ?

And many of Leo's pickups failed because of corrosion. If you read Leo's patent on wax potting, it was done to stop moisture from getting into the windings. If you have air in the coil, that won't work very well. There is no disadvantage to vacuum potting. Don't just blindly do what Leo did.

Please name all the pickup makers that "flash pot" their pickups. You said "most pickup makers." I really doubt that. I think the majority of pickup makers keep the bobbin in long enough to get the wax all the way into the coil, and/or vacuum pot. If they aren't, then they are living under some kind of misconception that it sounds better if you don't. No one has proven that yet.

Didn't you get the memo on that?

I don't have a vacuum setup yet, but that's coming. But I do leave my bobbins in for 10 minutes, and after having cut some wire off a few I know the wax gets all the way in pretty well.

[David Schwab]

Thank you DS, for the contribution; I wonder now, what two grams would amount to - 200turns, maybe?

It's inconsequential is what it is. Don't worry about 2 grams of wax. And don't forget that the original windings had wax in them. So if you are winding to weight, and no one does that, wind 2 grams less. I weigh some pickup just to get me in the ball park.

But I never thought about it until you asked in this thread. I have no plans on thinking about it any further. lol

You won't ever hear 200 turns, so why bother?