Pickup covers soldering

[pingu]

Hi ,

How powerful a soldering iron
should I need to attach an old Humbucker
pickup cover I've already got to a
brand new pickup I've bought ....



I know I need to heat and tin the baseplate fairly quickly without
heating the whole pickup too much ....

I've got a 40watt iron

many thanks

[bluenote61]

I think it might be helpful to sand the soldering points first, on both the cover and the baseplate.
40W might be little bit less for soldering. But sanded contact points are helpful anyhow.

[nevershouldhavesoldit]

A 40 watt iron is marginal for best results. The basic principle of soldering is that the metals being soldered together must be hot enough to melt the solder directly. If you just melt the solder on the tip of the iron and run it onto the parts, the joint will not be solid, so it will be a resistor in the circuit. This is why you need a sufficiently hot tip on an iron that has an adequate power supply to deliver that heat to your intended joint.

These days, an old fashioned soldering iron or gun is simply old fashioned. I've been using a "soldering station" for about a year now, and the results are so much better that it's amazing. Just set the tip temperature after selecting a tip with the right size and shape for the pieces you're joining. The bigger chisel tip is probably best for p'up covers. "Tin" the tip by heating it up and melting solder directly on it. I wipe the hot tip with the sponge or cloth that came with the station, but I used to use a paper towel. The tip isn't ready for use until it has a thin, shiny coating of solder on it.

Clean the surfaces well, and apply heat until the solder melts when it touches the parts to be joined and flows over them. Do not try to push the solder from the tip onto the joint - it has to flow on its own to make a good electrical connection. If you've never soldered before, practice with some scrap metal pieces until it's second nature. It's not hard, but the solder has to flow easily onto both parts and you don't want to overheat them. Do not remove the tip from the joint until there's enough solder to cover both surfaces at the join, and don't turn off the heat until the tip is clear of the work. If a peak of solder comes up with the tip when you pull it away, the join wasn't hot enough and should be redone.

Do not move or shake the assembly until it's cooled down well below the melting point of the solder. I generally let it sit until I can touch it. The solder should be shiny and smooth looking - if it's hazy or rough looking, the joint's probably "cold" and should be redone.

I can't find a pictue of the exact one I got from Amazon, but they're all pretty much the same at a given price point. Mine (similar to this one, also at Amazon) was $40 USD and solders much quicker and easier than my old Weller 150W gun. This is a typical unit:

[Jimmy Smith]

If you don't have temperature control on the 40 watt iron, it won't cut it for a big job where you need a lot of heat transfer.

You need more wattage, or just do what nevershouldhavesold it said and get a nice soldering station since they aren't expensive and are real effective with temperature control and different tips etc.

(I used to use a 45 watt for the regular fine soldering like pot and switch terminals and then use a 100 watt for big jobs like pot backs or pup covers.)

[pingu]

thanks all

[pingu]

I’ve got this one
It 60 watts I think

it goes to 480 degrees


is that suitable ?

[nevershouldhavesoldit]

I’ve got this one
It 60 watts I think

it goes to 480 degrees

is that suitable ?

I use 625F and a medium chisel tip for larger pieces like a pickup. You have to work fast to heat the area to receive the solder without letting the heat spread too high and too far.

[pingu]

i had a thought ….

i could partially dis-assemble the
pickup , before i pre-tin the base plate
on each side

that way i won’t risk melting the
plastic coil formers etc , which i was a
bit worried about

then reassemble the pickup , fit the
(already pretinned) cover and just
melt the two together

Is that a good Idea ?

[pingu]

1281110[/URL]]I use 625F and a medium chisel tip for larger pieces like a pickup. You have to work fast to heat the area to receive the solder without letting the heat spread too high and too far.

yes thanks , yes I think I’m gonna dis- assemble the pickup , to be safe

[nevershouldhavesoldit]

i had a thought ….

i could partially dis-assemble the
pickup , before i pre-tin the base plate
on each side

that way i won’t risk melting the
plastic coil formers etc , which i was a
bit worried about

then reassemble the pickup , fit the
(already pretinned) cover and just
melt the two together

Is that a good Idea ?

You run the risk of leaving a cold joint by doing that. Pretinning is a good thing, but you still need to heat the parts enough to melt the solder that’s already on them. Just meltiing the surfaces of the tinning enough to get them to bond can partially melt the solder that’s immediately against the surfaces. The temperature gradients can cause the solder to crystallize, which leaves it in a partially nonconductive state - this is what’s called a cold joint.

All of this discussion is based as much on electrical conductivity as it is on the physical strength of the joint. And a cold joint isn’t as strong as a well done one. How important a good ground connection is for a humbucker’s cover is debatable, given the widespread use of uncovered ‘buckers without noise problems. If you play in a location with a lot of RFI, stray electrical fields etc, it could make a big difference in noise level in your guitar signal.

The club in which I play regularly is directly next to both an electric regional rail line and a cell tower. The noise through single coil p’ups is astoundingly loud when calls are going through the tower, and the baseline is quite annoying below this. Positions 2 and 4 on a standard Strat cut the noise a bit, but it’s still quite audible. Even the fully shielded active EMG in my FrankenPaul picks up some noise when I hold it in certain positions on stage.

There’s little physical stress on a pickup cover. So you might get away with a marginal joint and could even do with a strong nonconductive adhesive paste like Flexseal if noise isn’t a problem. But properly soldering it is the usual way to go.

[TedBPhx]

Totally confused. But the only dumb question is the one not asked.
Why is the cover soldered to the pickup? For ground? Won’t the magnetic fields generated by the coils naturally flow through the cover with no electrical contact needed?

[nevershouldhavesoldit]

Totally confused. But the only dumb question is the one not asked.
Why is the cover soldered to the pickup? For ground? Won’t the magnetic fields generated by the coils naturally flow through the cover with no electrical contact needed?

Many think that a well grounded cover is a shield against RFI and other electrical noise through the pickups. As I suggested, though, there are so many uncovered pickups in common use by everyone from home hobby players to stadium rockers that noise is clearly not a big problem with uncovered humbuckers.

But any ferrous metal placed in or near the pickup’s magnetic field(s) can distort them and alter tone. There are also electrical issues like microphonics and resonances that some believe can be caused by pickup covers that are either mechanically unstable (ie can move or vibrate) or ungrounded, or both. So covers are controversial and a loose one could even buzz.

If a pickup cover is used, most experts recommend both securely fixing it in place and grounding it. I really don’t know if this is universally necessary, but I’d do it just to avoid possibly having to go back in again.

[Jimmy Smith]

I’ve got this one
It 60 watts I think

it goes to 480 degrees


is that suitable ?

Yes, 480 Celsius is enough heat. Give that a try. The cover and baseplate won't get hot enough to damage the pickup unless you hold the iron on them for a long time. Just put the iron on full blast and get in there for a few seconds and get a good joint.

[nevershouldhavesoldit]

Yes, 480 Celsius is enough heat.

I see that the dial says C, but 480C would be 896F, which is far too hot for soldering. I've never seen a pencil soldering iron that could sustain a temp anywhere near that high. The general guidelines for soldering are 600°- 650°F (316°- 343°C) for lead-based solder and 650°- 700°F (343°- 371°C) for lead-free solder. That's why the numbers above that are red on the dial - the device is not designed to be used at temps that high. The temp range for brazing starts at about 800F.

[Jimmy Smith]

You're right. You don't need excessive heat. I've never been in danger of brazing anything with all the excessive heat I've used in the past. However, as the iron gets too hot it burns up and degrades the solder. You want the temp hot to heat up the cover and baseplate enough, but not so hot that it destroys the solder.

[nevershouldhavesoldit]

You're right. You don't need excessive heat. I've never been in danger of brazing anything with all the excessive heat I've used in the past. However, as the iron gets too hot it burns up and degrades the solder. You want the temp hot to heat up the cover and baseplate enough, but not so hot that it destroys the solder.

You should never set the iron above the proper temperature for the job at hand - it should not be any higher 650F at the most for soldering with leaded solder and 700F for lead-free solder. You need to use an iron with enough power to maintain the set temperature even while transferring heat to the workpieces to make them hot enough to melt the solder. Don't confuse temperature with energy. The tip is just a resistance element that heats up like any other resistor when current flows through it. As soon as you touch the tip to the workpiece, it starts to cool down and the power supply in the iron has to pump more energy into the tip to maintain heat transfer. The wattage rating is a measure of how powerful the power supply is, not how hot the tip will get on its own.

Think of a deep fryer - the oil is at 350 and you're ready to start frying in it, so you toss in a handful of potatoes. They're much colder than the oil and they immediately cool it down, so that frying doesn't start until it heats back up to 350. Whether and how fast it can do that depends on the power of the heating element. Commercial fryers can maintain their set temperature even if you toss in 5 pounds of frozen onion rings. But tiny home fryers can't do that, so the oil cools down rapidly and never comes back up to temperature if you put too much food in it at once.

A soldering iron has the same problem - it has to be able to deliver enough energy to the tip to maintain its temperature while also transferring heat to the workpieces. You can grossly overheat the tip, but it won't transfer more energy just because it's hotter - it will simply cool down if the power supply is inadequate. If the temperature regulation mechanism is good and the power supply has enough reserve, the tip temp will stay at 650 while the workpiece heats up, so you can get the solder on the joint quickly and remove the heat before it does damage to the parts.

You're not "in danger of brazing anything" because brazing uses brazing rod rather than solder. Brazing is similar to soldering in that it uses a metal filler to hold other metals together. But brazing is done above 840F and brazing rod is largely copper and zinc (whith totally different mechanical properties). Soldering is done with tin and lead at or below 650F or at / below 700F using lead-free solder (which is made of various alloys of copper, silver, nickel, and / or zinc). Brazing is miuch stronger than soldering, but the two processes are most often used on different metals.

[Jimmy Smith]

I know. It's not an exact science though with the shoddy little soldering irons. If you set the temp high enough to liquify the solder, heat up the cover and baseplate enough to bond, and to deal with the heat loss of the iron, but low enough so it doesn't outright destroy the solder, that's a good range.

[pingu]

done it ,
well ….
it’s not very pretty under there ….
but it is mechanically stable
and electrically the cover is
earthed

thanks for all the tips

[pingu]

Sorry dupe

[sgosnell]

You can delete a post by choosing edit, then delete as the editing method.

[rpjazzguitar]

I appreciate all the technical info on soldering. This thread will improve how I do it.

Thanks.