Quick ground/shield question (or three...)

[Viper Jazz]

Howdy, all!  I'm building a semihollow strat (wenge top, mahogany body, maple neck) and have run into a few minor speedbumps in the wiring process.  After quite a few cuts on my thumbs, the guitar is now shielded.  Yes, I've read the arguments for and against, but I had already bought the copper tape at that point.

My question is where to attach the ground?  It's a fixed bridge and I'm using the technique described here where a strip of copper tape is attached leading from the ground wire to the body of the guitar itself (see pic).  So one end of the ground wire will terminate under the bridge, but where does the other go?  Do I attach it to the copper shielding itself in the control cavity, or does it go where all the other grounds go (soldered to my vol pot)?  Also, can you see in the pic if there are any ground loops?  All ground leads from pots are terminating at the vol pot right now.  Also, I'll have a strip of copper leading out of the cavity to a screw hole for the pickguard, but do I only need to do that for one of the holes, or for all of them?  And does that provide a ground for the shielding of the pickguard and the shielding of the cavity?

Lastly, my main problem right now is that I can't get a ground wire through the hole from the bridge to the body cavity (again, see pic)!  Because it's a semihollow body, it seems that when I thread wire into the hole, it gets lost in a cavity instead of getting pushed through the 2nd hole.  At least that's what I think is happening--all I know is that I can thread about 5 ft. of wire into the bridge ground hole w/o it coming out at the body cavity hole.  Any ideas?  I tried a coat hanger but it was too stiff and thick.  Halp!

 

[Viper Jazz]

Bump?

 

[Mr Real Nice]

I don't know about the other stuff, but maybe mechanic's wire will be thin enough to fit through the hole along with your wire?

 

[dbw]

Try going the other direction?

 

[onedrop]

My question is where to attach the ground?  It's a fixed bridge and I'm using the technique described here where a strip of copper tape is attached leading from the ground wire to the body of the guitar itself (see pic).  So one end of the ground wire will terminate under the bridge, but where does the other go?  Do I attach it to the copper shielding itself in the control cavity, or does it go where all the other grounds go (soldered to my vol pot)?

Soldered to your volume pot (or wherever your common ground point is).

Also, I'll have a strip of copper leading out of the cavity to a screw hole for the pickguard, but do I only need to do that for one of the holes, or for all of them?  And does that provide a ground for the shielding of the pickguard and the shielding of the cavity?

One is probably enough, as long as there is contact between the shielding on the pickguard and inside the cavity, you should be fine.

Lastly, my main problem right now is that I can't get a ground wire through the hole from the bridge to the body cavity (again, see pic)!  Because it's a semihollow body, it seems that when I thread wire into the hole, it gets lost in a cavity instead of getting pushed through the 2nd hole.  At least that's what I think is happening--all I know is that I can thread about 5 ft. of wire into the bridge ground hole w/o it coming out at the body cavity hole.  Any ideas?  I tried a coat hanger but it was too stiff and thick.  Halp!

Maybe try a guitar string??

 

[jmasin]

It's actually a little hard to tell in your pics what you are referencing, not to be a jerk but they are pretty dark.

For the ground loops - it looks like you have soldered the body of each pot up to the vol pot.  This is not necessary.  Your pickguard is shielded so all pots are grounded through the physical contact with the foiled pickguard.  Additional wires from the bodies of the pots create the loops.

As far as the bridge, you can solder it to the vol pot.  Electrically you could solder to the copper, but that would be another loop.

For feeding through the hole, I'm not sure I can help, it's hard to see.  Do you have a thin but more rigid wire you can feed through first as a "pull" for the ground wire?  (ala feeding wire through a wall).

 

[Viper Jazz]

Thanks, guys!  Sorry about the dark pics, it's tough to get light w/o reflection w/ all that shielding...

I've tried threading from the other end w/ multiple materials, but maybe a guitar string is just pliable and yet stiff enough.  The tool is close at hand, I guess.

As for possible ground loops, I didn't think that the pots actually touched the shielding on the pickguard, but I'll double-check.  Thanks again!

 

[guitlouie]

Hey Viper Jazz, getting the ground wire from the control cavity to the bridge for grounding on my chambered Strat was the single biggest pain in the butt that I have encountered on my two builds, and it was something I did not really see causing a problem before I actually attempted it.  What I did was to grab some jewelry making wire from a craft shop, it had the perfect pliability to stiffness ratio, and ran it from the bridge to the cavity.  Still, though I kept losing it in a hollow part of the guitar.  I would push like a foot of wire through and never see the other end.  Extremely frustrating!  Well, I just kept poking around until I got lucky, then I scared the crap out of my kids with my whoops and hollers of victory!  Keep at it, you'll get it!

 

[Ted]

From my experience, I had no need to shield the pickup cavities or the control rout on a Strat.

Some people (pickup manufacturers / luthiers) have stated that copper tape in pickup cavities can affect the magnetic field around the pickups. Personally, I would remove it, I think its overkill.

For my strat I only shielded the scratch plate and I have zero noise / interference.

If you feel you must shield, I recommend conductive paint, which is much easier to work with.