Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by John Coloccia, Apr 3, 2014.
Awesome, thank you!
I got "Big Bertha", my big soldering iron, at a garage sale for $5 many years ago. Without a Big Bertha you are never going to correctly solder to the chassis of an amp or the brass grounding plate, or other big heat sink areas.
Similar 200 Watt irons are available on ebay, but I have no idea if they are as good as Big Bertha:
Here is a common bad soldering job that I see all the time: Someone tried to solder the brass grounding plate on this 1975 Twin to the chassis by dropping blobs of solder onto the joint until there was a big pile of solder like a little pile of silver poo on the chassis. Unfortunately, this solder never sticks, and this blob was completely loose, and worse yet, making intermittent contact.
The typical soldering iron for circuit wiring is simply too wimpy to solder big heat sinks; even if you leave it on the area for hours, it will never get hot enough.
If you are going to successfully solder to the chassis, as for instance the transformer center taps soldered to the chassis, cleanliness is everything. Clean the area with a solvent, then with fine sandpaper or a red Scotchbrite pad, and then scratch the area with an awl or the edge of a screw driver to make a small cross-hatched pad for the solder to stick to. The time you spend preparing the area for solder is time well spent.
Big Bertha is way more powerful than my soldering station, but I don't really need to solder things as difficult as that. I'm guessing you have a lower powered iron for the circuitry. I'm afraid to recommend irons that I don't know much about. There are some cheap asian 'Reflow Stations' on ebay. I bought one a few years ago. I didn't need to use it until a few months after I bought it, and it didn't power on. I heard that someone was badly injured or died from getting electrocuted by one of those.
no amp builder i, and i guess with the big ol' monster iron it doesn't matter, but could you not in this example solder those leads to that brass plate before bolting it to the massive heat sink of the chassis?
maybe even say, laying it in place but with a sheet of paper or something under it as insulation?
Well, the brass grounding plate is a pretty big heatsink by itself, so I'm not sure that would work. I've never tried it, though. The idea of soldering in place is so that you can solder the ground wire to the brass plate and the brass plate to the chassis at the same time - that way the brass plate has a good soldered connection to the chassis. Fender realized that without a soldered connection, that the brass grounding plate could corrode and/or loosen and result in a poor ground. As far as I know, Fender did this on all amps from the 1940s through at least the Silverface era.
oh, you're soldering the plate to the chassis too.
You need a JBC Iron, man! You don't live anywhere near Hartford, CT do you? If so, we should get together and see what this thing can do on a really challenging job.
Walter explained it very well. Often, I'll swipe just the slightest bit of solder between the iron and the work just as I'm bringing in the iron to form my bridge. It's one of those things that takes a bit of practice but becomes second nature after a while. The key is that you still flow solder in from the other side once the area heats up. The bridge is strictly there as a heat transfer device, though it often does become part of the joint AFTER you add more solder and the flux from the fresh solder allows the entire area to flow out. Easier to show than describe, but if you play with it for a bit you'll see exactly what I mean. Solder is useless without flux, and the flux burns off almost instantly when you apply heat. That's the smoke you see...vaporized flux.
Early in in this thread a cable making/soldering vid was in line for videos John wanted to make. Any chance you can still do that John? I watched your attempt at breaking a cable, but that was all I could find.
Either way, thanx for what you've already provided.
I just got caught up with other things. I still plan on doing it some day. May happen fairly soon, actually. But yeah, if you build them the way I do with the same supplies and techniques, you'll have a helluva time ever breaking one, and you'll understand exactly why it's so darn reliable.
Bumping for the kids in the back
John’s videos were so helpful for me. I would recommend them to even experienced people
This bump was totally called for.
Love these videos. So much fun stuff and masterful narration. Thanks.
This may have been covered here already, I haven't read the whole thread, has anyone spoken about being green in the workshop, I use leaded 60/40 solder a lot of the time and I have decided to put all waste solder (from my solder vacuum when replacing components for customers, and those tiny last bits of solder that are too small to hold and use) in a big snap top jam jar, and not in the bin, as I'm pretty sure that is very bad and I don't think it can go in to the conventional recycling, so is anyone else doing this? and where could I go to put the waste solder to use? I'm in the UK its very difficult to know what can be recycled in general over here, guitar strings for example bin or recycle?
I'm not doing it, and if anybody ever catches me doing it, they have my permission in advance to shoot me right between the eyes and put me out of my misery.
A lead round or ROHS?
We have three separate disposals for batteries, fluoro tubes, and e-waste, over and above general waste and general recyclable. I'm putting solder in the e-waste, as half the stuff in there contains leaded solder anyway.
The web might lead to a nearby e-waste. Currys or Maplins may know?
Sort of on topic - what lead free solders and fluxes are people having good results with on our 1950s style pots and switches? Anything made in the last decade is likely ROHS, and I prefer to keep something labelled ROHS truly ROHS.
I bought a roll of SN100C a while ago, which worked OK on new boards/components, but quite hard to rework.
I also have a old roll of Sn96Ag4, it will just not wet some connectors, OK with others. I see that people are mostly selling Sn96Ag3.5Cu0.5 now, so maybe the little bit of copper makes all the difference?
Anyone found something that mostly works, or that they're moderately happy with?
If you were throwing out car batteries I would be more concerned.
A lifetime's accumulation of solder splashes cannot amount to serious environmental impact.
One shotgun shell has likely spread more lead into the environment than a handful of solder droppings in a landfill waste area.
Fair enough, I suppose it comes from the ground anyway, just trying to do my bit.
That's a point that's often overlooked. Lead is a base element, so nobody's making any "new" lead, or adding to the supply somehow, so we're not making anything worse by using it. It's just getting moved around.