I keep burning plastic covering on the wires!

[clintonb]

I'm a newbie at modding amps. One problem I keep running into is that when I'm soldering a connection, the plastic wire starts melting back, and then it's exposing too much bare wire. Sometimes I replace the wire. Often, I'm lazy and I just bend the wire so it won't accidentally make contact with anything else. Do any of you other builders have this problem? How do you avoid it?

Another annoying problem is that I accidentally touch and burn other wires with my soldering iron when trying to make connections. Sometimes I feel like i'm maneuvering through a maze of wires to get the place where I want to solder a connection. Any hints on how to avoid this problem?

Is there a particular order in which you build your amps that makes it easier to avoid working in tight places?

- Clint

[DirtyGeorge]

Avoid overheating when soldering. Try to heat the wire and terminal at the same time (iron tip touching both) and just long enough to flow the solder. Keep the iron tip clean and enough solder on it to make good thermal contact.
As for touching insulation on other wires you just need to be careful. I'm not very careful myself so I use teflon insulated wire in my builds.

[clintonb]

Thanks for the advice.

I guess I just need more practice soldering.
I'll have to try teflon wires for my next project.

- Clint

[dai h.]

just basically a matter of technique in that if you're consistingly melting, you're prob'ly taking too long.

Try to heat the wire and terminal at the same time

this is a really good point. EVERYTHING that is to be soldered, that is every wire, lead, lug on that joint ALL have to be heated to the temperature it takes to melt the solder. So you have to think about the capacity of the iron, how you approach and contact the joint with the tip, the size of the tip, dia. of the solder (bigger = more heat to melt). Also make sure everything is clean. No grime, dirt, oils, oxidation. They can hinder the process and make a joint not possible or contribute to excessive application of heat leading to a higher likelihood of melting insulation. For brand new parts right out a package, prob'ly not necessary, but anything that has been sitting around (esp. old stuff) may need to be cleaned (denatured alcohol--I get mine at the drug store, naphtha--I use Zippo lighter fluid, also spraying with Deoxit and leaving overnight in a baggie or plastic container, etc.). Make sure nothing moves when you make the joint. Generally 2 to 3 seconds max. is about correct (unless it's something that is big and sinks heat and won't become damaged even with lots of heat applied). Practice can help. Handbooks, instructional materials that you can find on the net (NASA, MIL stuff, stuff from solder manf.s such as Kester, etc.) might also help to get a better sense of what is right and not. Scope out stuff that is well made too. Old military, industrial tube equip., some amps, etc.

[dai h.]

oh yeah, forgot to add re: cramped quarters wiring. Someone on the plexi palace bbs had a good idea which was to temporarily cover wires close to where you're soldering with aluminum foil. This way, even if you accidentally touch the insulation, it won't burn. But, REMEMBER TO TAKE IT OFF when you are through! Very untoward things can happen otherwise... . Also, I temporarily tie wires out of the way with those plastic covered bits of wire use on bread packages, etc.

[Mouthurst]

wire

Clint-Get good quality wire, I mean like dont use the cheap stuff. Use teflon if you can. Also as some have sugessted make sure the iron is hot before you touch it, and any "shapes" pre bent then "tinned", before you stick them into socket terminals or whatever. At least thats what I do.
It IS a skill and comes with practise.
Good luck and have fun safley.

[dai h.]

Teflon has certain advantages but it's not a requirement. Technique more than Teflon IMO. In certain cases I think Teflon can actually be worse for reliability since it is stiffer than PVC and it won't absorb vibration as well which could mean a joint snapping or cracking. Also if your technique is such that it requires Teflon, what happens when you can't avoid soldering PVC wire? A lot of wire is PVC--amps, pickups, efx, etc.etc. Also as I understand PVC is not all the same and there are different grades as well.

[bob p]

Teflon has certain advantages but it's not a requirement. Technique more than Teflon IMO. In certain cases I think Teflon can actually be worse for reliability since it is stiffer than PVC and it won't absorb vibration as well which could mean a joint snapping or cracking. Also if your technique is such that it requires Teflon, what happens when you can't avoid soldering PVC wire? A lot of wire is PVC--amps, pickups, efx, etc.etc. Also as I understand PVC is not all the same and there are different grades as well.

i'll step out on a limb and say that Teflon wire is BAD. sure, PVC melts easily and Teflon doesn't, but as Dai has already pointed out, once you practice your technique, its easy enough to solder PVC wire without melting it and you don't NEED Teflon wire to cover up your mistakes.

so why is Teflon bad, IMO? COLD-FORMING. I bought some very expensive Mercury Magnetics Plexi-style OTs that came with Teflon wires. I can't explain how Teflon wire found its way to a 100% vintage repro transformer, but its there nonetheless. the problem was that the wires were wrapped around the base of the transformer when it was shipped, and there was enough weight on the wires to deform the insulation and expose the wire core. that's a known problem with Teflon, and it doesn't happen with PVC.

[dai h.]

yes, your post about Teflon leads vs. non-(not sure if the other OT had PVC) on some Merc.Mag. output transfrmrs. and the differences was one of the ones in mind when thinking Teflon wasn't necessarily superior (seemed like a good explanation though I forget the particulars--maybe something about "abrasion"??--one of the points might have been that Teflon rips easier when it rubs against sharp edges but I don't quite remember). One possible solution is when choosing teflon, try to find something flexible. Maybe a wire with lots of stranding and/or go to a skinnier gauge (which will be fine for some runs in an amp where there is little current flow).

[Enzo]

You need to solder with confidence. Solder the joint and then get off it. One sure way to build up excess heat is to not heat the joint enough and then reheat it a couple times to try to get the solder to melt right. Heat the joint thoroughly and flow solder into it. No reheat touchups!!!

REmember, solder is not glue. You heat the joint until IT melts the solder. DO not melt the solder on the tip of the iron and let it flow onto the joint. Seriously, if you are putting the solder against the tip of the iron, you are doing it wrong. I will sometimes melt a little on the ti[p first to wet the surface, but when the actual joint is soldered, the joint does the solder melting.

Get some little heat sinks. Here are some at MCM:

http://www.mcminone.com/product.asp?...%5Fid=21%2D675

Clup them on the wire before soldering. CLip them right at the end of the insulation. They are thin so they don't take up a lot of space along the wire. A small test lead clip will work too, though it has a slughtly wider snout than these. Clip a test lead onto the wire at the end of the insulation. The stuff won't melt, the clip acts as a heat sink.

[Enzo]

And don't forget the equipment. Keep the iron tip clean. A rag works, but a nice official damp solder iron tip cleaning sponge works wonders. Wipe before each solder job. Just sitting there, the solder on the iron tip oxidizes, so each time you pick it up, wipe it. Takes half a second.

Keep a good tip in the iron, a mangy old pitted tip will not make as good thermal contact with the joint. A shiny smooth tip will.

Use a hot enough iron. For eyelet boards, tube sockets and so on, I would not use a little 5 watt iron meant for fine pcb work. I just resoldered all the connections on an old Fender 5C3 eyelet board yesterday. I got out my weller gun, screw the iron.

I have been soldering for over 50 years, I like to think I am reasonably good at it. But I will admit I burn a wire now and then myself. And I melt the top of a cap or something once in a while - shit happens. SO no one if perfect, just practice doing it right. DOn't be afraid to actually read a booklet on how to solder.

[Regis]

I have been soldering for over 50 years,

50 years!!!

Good Grief, did they even have electricity back then???

I thought I was old, and I've been soldering since 1966!!!

[clintonb]

What about soldering irons, are certain brands better than others. I've been using a 40-watt soldering iron from Radio Shack. What I hate about it is that the tip takes forever to get hot. The rest of the iron heats up way before the tip does.

I looked at some websites and online videos for soldering yesterday. It looks like everyone is using a temparature-controlled soldering iron station. What temperature or wattage is ideal?

Also I have concerns about tip cleaner. I've been using tip cleaner I got at Radio Shack, but the little tin of tip cleaner got dirty pretty quickly. The tip cleaner has black residue. It seems like I'm cleaning my tip with dirty tip cleaner.

What about a wet sponge for wiping off the tip. I was using a dishwashing sponge. But it seems like when I wipe off the tip on the sponge, I'm getting fibers from the sponge on the tip. Is the sponge that comes with those soldering stations a special type of sponge?

[dai h.]

What about soldering irons, are certain brands better than others.

apparently yes, in general. Here (in Japan) Hakko seems to have a good reputation. "(G)oot" brand (Taiyo Electric) stuff doesn't seem too hot, however some irons sold under their brand are imported (like their Portasols which are the same sold by Weller), so it might depend on the particular series. I don't know too much about different brands but I suppose it wouldn't be a bad thing to do some searching on ones you might purchase.

I've been using a 40-watt soldering iron from Radio Shack. What I hate about it is that the tip takes forever to get hot. The rest of the iron heats up way before the tip does.

I'd say a 40 or even a 60W is good for tube amps in general except for things like chassis grounds. If it feels like it takes too much time to work up to temp. maybe try an iron with a cermic heating element. Those come up faster.

I looked at some websites and online videos for soldering yesterday. It looks like everyone is using a temparature-controlled soldering iron station. What temperature or wattage is ideal?

I don't think they are necessary but can be nice and why not I suppose if you can drop the cash on a nice station. Cheap (non-temp. controlled) ones usually end up overheated after a while so you have to turn them off to cool them down a bit.

Also I have concerns about tip cleaner. I've been using tip cleaner I got at Radio Shack, but the little tin of tip cleaner got dirty pretty quickly. The tip cleaner has black residue. It seems like I'm cleaning my tip with dirty tip cleaner.

I had a small tin of tip cleaner with some hardened crystal-looking stuff, and it kind of seemed like it made the tip worse but maybe that tip was getting old, so not sure about that.

What about a wet sponge for wiping off the tip. I was using a dishwashing sponge. But it seems like when I wipe off the tip on the sponge, I'm getting fibers from the sponge on the tip. Is the sponge that comes with those soldering stations a special type of sponge?

according to some paper or article (some Kester paper?) I read you were supposed to use a cellulose sponge, so I guess that is what the sponges sold for the purpose are. I clean mine after a lot of use, or if really bad just throw it away. I also use distilled water (drug store--cheap since contact lens users use it?) on the sponge and try to control the amount of water (since hitting it w/the iron obviously can cool the tip temp.) When I can do things smoothly, I use a sort of flicking/twisting motion when cleaning the tip against the sponge which ideally removes all the old solder and leaves it clean.

If you find things aren't going smoothly, try to go over your whole process front to end and spot where you are doing things incorrectly (or not in an ideal way). Is too much heat? Too little? Too much time heating the solder (so all the flux evaporates and won't bond well anymore and oxidizes)? Oxidized contacts? Pushing the tip against the pad too hard? etc.etc. Maybe it's just something small, or maybe not--maybe a couple of things. Try to figure it out.

[Enzo]

I have a small Radio Shack iron in the drawer. If all my professional stuff dies, I get it out so i can still melt solder. But it really sucks as an iron.

COntrolled heat means a lot more on circuit boards than it does on eyelets or tube sockets. But I like a nice controlled heat. I use a Weller WTCP station - it sits on top of my Pace desoldering station. Now there is a step you will never regret once you get far enough to need one - a desolderer. The WTCP is noce, but there are plenty less expensive units.

The cheap tip in your cheap iron doesn't make good thermal contact within the heater of the iron. It gets oxidized, or the hole is loose enough than once tightened down, it is only really making contact with a little stripe down one side. And the finish on the tip makes a difference. the shiny tinned part might be hot enough to melt solder, but the dull oxidized parts right nest to that will not melt solder. They are hot enough, but cannot make a good thermal contct with the work surface.

Thermal contact is why we need to keep our tips clean and shiny.

DO this too. Once a tip is clean and well tinned, wipe it each time you pick it up. MAke that a habit. But the last time you put it back in the holfer, melt a litle glob of solder on the tip before pulling the plug. If you wipe it and turn it off, the shiny tinned sirface sits there hot and cooling free to oxidize. If you leave some melt on there, the solder oxidizes instead. next time you turn it on, that glob melts from the inside, and you can wipe it right off. The solder protects the tip.

SPonge is nothing special, but you want one that won't melt or break down under heat. A real sponge works. But a plain old rag works. Damp works better, but I don't worry about how damp. Soppy is too wet, but really, the iron recovers heat pretty quick from a quick wipe on a wet sponge. A little cotton rag made damp works as well as a sponge. Sometimes I just do a quick wipe on the leg of my jeans. Not on there long enough to burn me through the fabric.

ANd don't be cheap with the tips. When the tip is a worn down pitted nasty old nubbin, throw it out and mount a new one.

Good Grief, did they even have electricity back then???

Well, most of our amps ran on steam. You filled the extension cab with coal, and shovelled some in once in a while. Guys would argue whether you got better tone from anthracite or bituminous... But the tone stack had wires.

What we didn't have was transistors. They were a novelty. The hobby magazines had projects for them - mostly oscillators, or the occasional one transistor short wave antenna booster. Like the 12AX7 is the most popular signal amplifier tube today, back then, the main transistor was the CK722. Then they started those darn 2N numbers.

Much has changed.

My first solder iron was my dad's. It was one of those 100 watt things the size of a large screwdriver. The tip was maybe 3/4" across, and shaped like a pyramid. It was used for soldering copper plumbing. The tip was attrocious. But it was enough to strip down dead TV chassis for parts. Boy the day I got my first Weller 100/140 watt gun. Ah that was a red letter day. We didn't have circuit boards. Lot of turret boards in surplus electronics though. The mid 1950s was not at all long after world war 2, and there was a ton of surplus military electronics on the market. I was in Washington DC< and we had a number of surplus outlets. One place I liked sold stuff by the pound. Radar terminal, radio, power supply, whatever. Throw it on the scale.

Then there was the sad day I burned out my first Weller gun tip. They eventually wear through - it will happen to all of them. You bend it so the two halves touch and you can get a couple more solder joints out of it. But I found you could strip bare a few inches of solid 12ga house wire, and bend it double. CHuck that in the gun, and voila - a new cheap tip.