Problem after potting

[chriswhite]

I have been around a while but never posted but now I have a question.
Every once in a while when I pot a pickup it will read fine before but after I pot it will go between 25-45 m ohms. For instance I made a strat pup at 6.4k after I potted it it was 20-30m. I was unable to get this pup going without rewinding the whole thing.

what causes this and what can I do?

thanks

[big_teee]

Did You try resoldering the wires in the eyelets?
Welcome!
Terry

[chriswhite]

ya, I had spent a couple nights after work trying different things. At one point I had unwound the pickup half way and tested again and it was still doing it.

[big_teee]

ya, I had spent a couple nights after work trying different things. At one point I had unwound the pickup half way and tested again and it was still doing it.

Are you using Heavy Formvar, or Plain Enamel wire they are the hardest to get a good solder joint?
Terry

[chriswhite]

43 awg PE. I was just chatting with a friend who has a masters in electrical engineering and he thinks that the wax was/is too hot and it caused a break in the wire and now the multimeter is reading close to infinite resistance as a result. He is not familiar with pickups specifically

[big_teee]

Hey Chris:
I sent you a PM of My process, You can compare it to yours.
Good Luck,
Terry

[the great waldo]

It´s definitely a break in the coil if you´re getting such a high resistance reading and resoldering the eyelet connection is not curing it. Maybe your winding a bit to tight and the heat is snapping the wire. Try dropping the wax temperature a bit. Otherwise it´s a rewind.

Cheers

Andrew

[Jazz P Bass]

43 awg PE. I was just chatting with a friend who has a masters in electrical engineering and he thinks that the wax was/is too hot and it caused a break in the wire and now the multimeter is reading close to infinite resistance as a result. He is not familiar with pickups specifically

Please correct me if I am wrong, as I am confused by this post.
Wax melts at 46 - 68 C (114-154 F)
PE melts at 258 C.
Copper melts at 1084 C.
How can the potting process "break" the wire?
Here is a nice wire link: MWS Wire Industries - Frequently Asked Questions - FAQs

[big_teee]

Please correct me if I am wrong, as I am confused by this post.
Wax melts at 46 - 68 C (114-154 F)
PE melts at 258 C.
Copper melts at 1084 C.
How can the potting process "break" the wire?
Here is a nice wire link: MWS Wire Industries - Frequently Asked Questions - FAQs

Hey Jazz:
We need some of that Micro Square!
That looks Cool.
Has anyone ever tried any of that?
On the wire breaking issue.
The only issues I've had with SCs is the Magnet shorting issue.
If you wind too tight, you get flared bobbins.
I've broke wire before at the eyelets, but was more or less user error.
If you keep your wax pot under 160f, I don't see any problems.
Now if you have rough un-protected magnets, and you beat around on the magnets, moving them up and down, you can break wire!
Terry

[chriswhite]

thanks, guys. Since i used 43 awg I did break the wire a couple times and I wouldnt be too surprised if it even broke at the solder joints where I reconnected the wire. The wax definitely isn't hot enough to melt the insulation but I think maybe the wire is too tight and it buckles under the strain.

[Jazz P Bass]

Yeah, I saw that square wire & thought "Hmmmm. I wonder if...."
It would most likely be a PITA to get it to line up as in the manufacturers drawing

[Jazz P Bass]

That little ditty about "broke the wire a few times" would have been good information to supply at the beginning of the post.

[big_teee]

That little ditty about "broke the wire a few times" would have been good information to supply at the beginning of the post.

That would be my Main Concern Also!
T

[copperheadroads]

I have been around a while but never posted but now I have a question.
Every once in a while when I pot a pickup it will read fine before but after I pot it will go between 25-45 m ohms. For instance I made a strat pup at 6.4k after I potted it it was 20-30m. I was unable to get this pup going without rewinding the whole thing.
thanks

Just check with your meter for continuity, Between your magnets & your lead wires

[chriswhite]

*bites lip* my bad. I had told big_teee in a PM that I was mostly concerned as to what caused it to jump to mohm's. I assumed that if the wire had broken then I would get an Overload on the multimeter and no signal at all.