Metal strips affecting pickups?

[mcgruff]

I have a guitar in which I need to change pickups frequently. I'm already using header strip as a connector so I can swap pickups without soldering and now I'm looking at mounting pickups from the back so I can whip them in and out without having to take the strings off. It's a hassle even with locking tuners plus I usually get only two or three changes before the strings start to snap at the point where they're gripped by the lock mechanism.

So I'm planning to gouge out the pickup routs right through the guitar body so I can mount pickups from the back. I'll also need to figure out some kind of adjustable, quick-release mounting thing but that shouldn't be too hard.

Now, as it happens the guitar in question is a 335 style with only a narrow solid block of wood down the centre. I'm afraid that punching through the pickup routs won't leave enough wood behind to hold the guitar together against the force of the strings and therefore the plan is to fit a couple of metal strips either side of the central block to reinforce the structure - 2mm thick and about 3cm wide or thereabouts.

Given that they'll run fairly close to the sides of the two humbuckers, will they have an affect on the pickups' magnetic fields and hence the tone? I don't mind taking this guitar apart and putting it back together with a scar or two (it's not a real 335..!) but I don't want to do anything to interfere with the sound.

[Rick Turner]

Theoretically you could introduce some eddy current losses that way. You might consider careful use of carbon fiber rods...maybe four of them...and then use something like Helicoils to put real machine threads into the wood there for mounting and adjusting your pickup swaps.

Use five pin headers with ground in the middle and what you'll assign to beginning and end to the ends. That way you can flip phase of a pickup by just flipping the header housing around. I'm going to 5 pin headers for all my new and "redesigned" pickups, and that's what I did on Duncan humbuckers for the Henman Guitar project. Works great.

[mcgruff]

Thanks Rick. I wondered about carbon fibre rods but I think the small sizes are quite flexible?

Five pin headers & center ground - snap! That's what I've finally settled on too. Only niggle is soldering wires to pins without melting the plastic so I sometimes just pull them then put them back with a spot of superglue.

[David Schwab]

Only niggle is soldering wires to pins without melting the plastic so I sometimes just pull them then put them back with a spot of superglue.

You don't solder wire to the pins! You use a crimper. But you attach the wires before you press them into the housing anyway. But if you solder, the pins (which are actually the sockets) get filled with solder and the headers (which are the plugs) wont fit in.

On the headers they will be soldered to a circuit board.

I did all my pickups this way for several years.

[mcgruff]

We must be talking at cross purposes: this the kind of thing I'm using.

[mcgruff]

OK I think I get it now. Doh!

[David Schwab]

We must be talking at cross purposes: this the kind of thing I'm using.

Yes, that's exactly what I'm talking about. That's the header. The pins are the female end. You crimp those onto the wire, you don't solder them.

You can find crimpers fairly cheap, and some that cost more than the guitar they are going into lol

I use one like the one on top here:

https://www.futurlec.com/Tools-Crimping.shtml

[Rick Turner]

The headers are made to be soldered to on the short end, and if you're melting the plastic, you're using too much heat, too big a soldering iron tip, the wrong solder, or some such thing. I tin the wires to which I'm crimping the female header connectors before crimping and get much better connections. I do all soldering with Kester SN62 which has 2% silver.

[mcgruff]

I didn't realise crimping was involved... I've just been soldering wires onto the ends of the pins of the headers and sockets shown here. I'll need to look into that. Thanks guys for the tip.

To reinforce the guitar, I think I might get away with just a wooden strip, maybe half-inch or so wide. Seems to be room for that in the body cavities although I might have to move a jack socket.

[Mike Sulzer]

To reinforce the guitar, I think I might get away with just a wooden strip, maybe half-inch or so wide. Seems to be room for that in the body cavities although I might have to move a jack socket.

I do not think the metal strips you proposed above intersect enough magnetic field in order to have a significant effect on the sound of the pickup through eddy current induction.

[Rick Turner]

Mike is most likely correct, but it's not that hard to put in CF. If you've got room for wood, you certainly have room for the much stiffer CF approach. It'll bond to wood better than metal, too.

[rdrr]

Do you plan on doing this to the neck pickup as well as the bridge pickup? Depending on how it's constructed doesn't that have the possibility of compromising the neck joint on a set neck if the tendon isnt very big and goes under the neck pickup.

[mcgruff]

Yes - neck and bridge. I didn't know I might be interfering with the neck joint. I'll have to look into that. Maybe I should take it to a luthiery forum.

Thanks everyone for your help. Making it easy to experiment is often an important first step because more experiments means more learning and discovery.

[Mike Sulzer]

Mike is most likely correct, but it's not that hard to put in CF. If you've got room for wood, you certainly have room for the much stiffer CF approach. It'll bond to wood better than metal, too.

A CF rod resists stretching, but flexes easily when pushed on. It would be hard to avoid that in this case. A rectangular sheet of metal on each side, screwed to the wood in several places, preferably glued with something like gorilla glue as well, does the job.

[Rick Turner]

Not to be argumentative, but if you put CF as close to the back and as close to the top as possible, you put it in the stretch and compressive zones where it does the most good. The idea is to not put most of the CF in the neutral flexture zone. I do sometimes because it's convenient, but ideally, you put CF at the surface of a beam for maximum efficient usage.

I'm just very used to working with the stuff, so it's a "go-to" solution in my bag of tricks.