Post by thetragichero on Mar 24, 2018 20:00:51 GMT -5
I'm gonna place this here for lack of a clearer subforum choice...
i have a couple of 100w soldering guns and that kinda seems like bringing a bazooka to a knife fight (why at 33 i am still attending knife fights is beyond me...) in most cases of guitar wiring. what kind of wattage would be sufficient?
fwiw, I've been pairing down my pickup collection so i have some funds in paypal for eBay shopping, and I'm not looking for cheap Chinese stuff for once lol (although i'd like to be right around the $20 price point)
If cost is an issue, you might be better off with a Chinese iron. I've used Weller irons like the one in your link. 40w should be plenty. And it is ... at first. But because of the way the tip is mounted in the heater, the interface oxidizes and the heat transfer from the heating element to the tip will degrade rather quickly.
Ungar made far superior irons and they went out of business. But Weller bought them and continues to market some of their irons under the Weller brand name. You'll find those marketed as "Modular Soldering Irons". I have some Ungars which are more than 40 years old with a ton of miles on them which still work well. I did have one (my first) fail after about 15 years of daily use. But that was more a case of abuse on my part.
For those new to this topic, a refresher might be in order.
A soldering gun (shaped somewhat like a pistol) is most often of the 100 watt category. They can be higher or lower in wattage, but in nearly all cases, that's way too much heat for what we do here, inside of a guitar (or a pedal, or even an amplifier). There are times when 40 watts' worth of heat might not be enough, and there are certainly times when a 20 watt iron will be ample, but for the most part, a simple pencil-like iron of 30 to 40 watts will do the job nicely.
The deal is, we see some highly different materials that we'd like to solder onto. Wires of very small diameter (20 or 22 gauge in your wiring scheme is ideal, 16 or 18 gauge is overkill, and harder to work with) need only 15 or 20 watts' worth of heat, whereas the back of most any pot requires double that amount. When you think about it, the reasons for each are very similar. You don't want to overheat something, that part's easy. For wire, you risk burning the insulation. For the back of a pot's metal shell, you risk burning the innards, thus rendering the pot null and void.
But wait, isn't a lower-wattage iron better, if you don't want to overheat the pot's shell?
No, bunky, that's not the way physics works. In fact, a higher wattage iron tip at a single spot will heat that contact-spot up much more quickly, thus causing the solder to melt sooner, allowing you to remove the iron/heat sooner. If you need to keep the iron on the pot's shell a long time in order to melt the solder, the whole shell is heating up, and sure as shootin', the pot's on its way to the dumpster. Don't be tempted to use a soldering gun here, 40 watts will work just as well, and greatly lower the risk of environmental damage. (And of course, the ancillary damage to your wallet.)
In fact, the only place I can recommend the use of a 100 watt gun (or even higher power) is in an amplifier where you need to solder grounding wires to a terminal that is screwed to the chassis, or even directly to the chassis itself. The reasoning is exactly the same as above - don't heat the whole chassis, which is absorbing heat at a phenomenal rate... heat up that contact point quickly, and remove the heat as soon as the solder has melted. This is the one time where a 40 watt iron will actually go cold trying to keep up, it simply can't do the job. The reverse of the bazooka/knife scenario, if you get my drift.
In all of the above message, the underlying meaning is that temperature is not what we're talking about. Most inexpensive irons sold today are single-temp units. Solder melts at about 600° F or a little more, most irons hit the mark at roughly 700° F. The controlling factor here is, how long does the iron need to recover the heat that's been dispersed into the item (wire, pot shell, etc.)? If it's low wattage, a long time will be necessary to get back to normal. A higher wattage can more easily cope with a large drain of heat, and recover more quickly.
Variable irons are nice, and in some cases are necessary (to prevent needing two or more irons on the bench), but for our needs, they're probably overkill. Not to mention, a larger outlay of cash that could've been used for more toys!
It is, however, worth investing in something that is properly temperature controlled. Enough to do pots in a few seconds even with a big tip will likely melt small contacts set into thermosoftening plastic and overheat small electronic components.
And don't waste your time with conical spike tips unless you're doing tiny surface mount stuff.
Fled across faculty from MechEng to CompSci, now revisiting the bit in between for analysis of an offshoot of a hobby... oops.