Help with soldering long leads with wire insulators

[mordechai]

I am try into wire up a few old Mullards for a tonebender circuit and want to leave the leads long and insulated like the DAM gut shots I've seen.  But I'm confused -- with the leads fully covered with the wire sheath insulation, how do I apply a heatsink to help dissipate the heat from the soldering iron?  In the pictures I've seen, the leads are completely covered, and I can't figure out how the transistors are soldered -- there's no space onto which the heat sink can clamp -- without getting fried by the soldering iron.  It's my understanding that if you apply solder to the lead underneath the PCB or veroboard, the heat sink needs to be situated between transistor itself and the point where the leads are fed into the top of the board.  What's the technique I should use here?

[Jdansti]

Quick efficient soldering without a heat sink.

[Arcane Analog]

Quick efficient soldering without a heat sink.

Yup. I have never used a heatsink and sockets are a bad idea for a number of reasons. If you solder properly you do not need a heatsink.

[R.G.]

Here's a test for whether you can solder well.

(1) cut off two 1/4W resistor leads to 1"/25.4mm and arrange one of them to stick vertically up in the air somehow so it will remain still for the following work
(2) hold the second resistor lead with your thumb and index finger
(3) solder the resistor lead held in your fingertips onto the midair end of the other resistor lead WHILE YOU HOLD THE RESISTOR LEAD in your fingertips
(4) don't burn yourself; there are two ways to not burn yourself
---(4a) let go when it gets too hot and the joint is still no good
---(4b) solder quickly enough and well enough that the joint is good and you are finished before the heat can travel up to your fingers

When you don't burn yourself, your preparation and technique is good enough.

NOTE-NOTE-NOTE
This is semi-humorous. Do not burn yourself doggedly trying this over and over. It is a semi-humours illustration of how fast good soldering is. I can - and do - do this myself. 1" is about the shortest lead I'll try this with, but I do it without thinking when I need a quick test pin to clip meters or oscilloscope to. But do not harm yourself trying this. Start with longer wires to illustrate the concept to yourself.

[armdnrdy]

(2) hold the second resistor lead with your thumb and index finger
(3) solder the resistor lead held in your fingertips onto the midair end of the other resistor lead WHILE YOU HOLD THE RESISTOR LEAD in your fingertips

(4) Post pictures of your fingertips after this procedure and you will be graded by forum members by the amount or lack of burns on your fingers. 

[davent]

Get someone else to hold the resistor lead so you can feed solder.

[R.G.]

The Devil sits on my left shoulder most of the time. Occasionally he whispers into my ear, and sometimes I take his evil suggestions when I am weak.   

One day, long ago and far away, in a different building, the Devil noted that it was common practice in the power supply lab to solder by simply pulling a length of solder off the spool on the bench and holding it near the end of the length, feeding it to the joint being made. And it reminded him of the odd coincidence that the solder on the benches was about the same diameter as the paper clips kept in the supplies room. He whispered that I should get a paper clip and straighten it out so it looked like not a paper clip, but more like a casually not-quite-straight length of solder. Worse - after all, this was the Devil - he whispered that if I was any good with a soldering iron at all, I could actually solder the end of the not-a-paper-clip-anymore to the end of the solder on the actual spool of solder.

Well, who can resist such a dig at one's manly abilities to solder well? I got the clip, straightened it out to a plausibly-solder-looking bit of wire, then after a few tries was able to solder the wire end to end with the remaining solder from the spool. "Hah!" I said to the Devil. "Now who did you say was the Soldering King of the lab?"   

"Very nice, indeed,' said the Devil. "Now go sit near the entry door to the lab where you can see the first time someone tries to solder with the paper clip that's attached to the roll of solder."

I could not resist. Not long later there was a yelp and cursing from that bench...

[Jdansti]

Hilarious!   

[armdnrdy]

Hilarious!   

+1

I'm an Industrial Electrical Contractor and one of my favorites is to reverse the blade on a hacksaw so that the teeth are facing back.

When someone goes to cut...the force is applied to the back end of the teeth. The blade will still cut but...it takes a lot longer with much more energy exerted! 

Another fave is attaching a large tie wrap to someone's drive shaft. When the drive shaft turns it makes all sorts of racket! It sounds like your engine has blown! 

[davent]

Japanese woodworking hand saws are designed to cut on the pull stroke, extremely sharp and very thin kerf,  like a hot knife through butter, a joy to use.

[PRR]

> want to leave the leads long

The reason the leads are long is SO it is harder to cook the Germanium.

I have a 400 foot wire here. If I heat one end, even with a blow-torch, the other end won't ever get hot.

As R.G. says, a "good" solder joint can be made so fast you can hold the lead an inch away. I've always soldered this way; however mostly on Silicon and yes I have built-up thick skin from holding things I should have let-go.

Practice getting in-and-out-and-Solid quickly.

Wrap a bit of wet paper-towel around the body of the transistor. Leave leads long, solder fast, it will be fine.

If you can barely pass the 1-inch test, do not solder all three legs at once. Let it cool a few seconds between leads.

[MrStab]

I have built-up thick skin from holding things I should have let-go.

i heard you can go blind from doing that too much

[PRR]

> you can go blind from doing that too much

I just got new glasses. Adjustable focus. Pretty cool.    

Adlens Continuously Adjustable Work Glasses

My distant vision needs a -2.25 correction. When wearing my "distance" glasses, when I was young, I could focus my eyes closer than infinity, to a foot or so. However age (or too much you-know) has weakened my eye's re-focusing.

I have reading glasses, and bi-focals. But as my accommodation fades, these give specific distances that "work". I'm covered for 48 inches, and 18 inches, and some others. But bending over a car fender squinting at a carb, sometimes I am at 30 inches and neither lens works right.

The Adlens turns from -6D to +3D. -6D is pretty near-sighted. Can't find the door on the barn at night. The Adlens will correct most eyes for distance vision.

But by turning-in the screw (to a more positive number, except it doesn't have numbers), you get best focus at some distance nearer than infinity. For a "normal" person (does not wear glasses to drive), +1 focuses at 40 inches with zero strain. +3 focuses at 13 inches. This covers a LOT of "close work". Near-sighted folks like me just don't turn it all the way to get down to a foot. If you got your nose in your work, a $5 set of +3 reading glasses over the Adlens will get you there.

This is for straight (spherical) focus. If you have significant astigmatism, the "best" focus will still be blurry, and you should consult the eyeglass expert with a clear measurement of your working distance to get fully-corrected lenses.

Disclosure: I got these specs no-cost, as a review sample. I _just_ got them, and have not got past the "golly!" stage, to look for flaws or limits. In a quick test (I have them on now) the zone of good focus is small (I'm used to big aviator lenses) and there is some spatial distortion (my slanted keyboard is looking flat). Not serious for close-work. I might not want to dance or drive in these things. Stairs may need special attention (bifocals will trip me up on stairs if I believe what I see too much).

[Jdansti]

I'll have to check those out.  I wonder if they make them with safety lenses. My guys at work might like them.

[duck_arse]

so, we won't expect the updated avatar for a while, prr?

"if ya let the devil ride, he's gonna want to drive", as they say on smokestack lightnin.

[R.G.]

Pondering my post a bit, I think one could turn that technique into a useful training tool.

One could take a length of wire, maybe 3-4"/ 75-100mm long, and hold it on one end, applying a well-tinned soldering iron to the other end. Note the amount of time it takes to get too hot to hold. Let it cool, then move in an inch, and re-solder the free end. How long did you have? Now another inch. How quick did you have to drop it?

This process would develop the necessary appreciation for how fast heat moves up a wire - and if done with different wire sizes, how much the surface-to-cross-sectional-area of the wire lets heat out the sides before it can travel up the wire. The skinnier the wire, the more heat gets out the sides as compared to moving up to the fingers.

It's a training tool that might develop a useful bit of experience for soldering faster than many, many soldering joints. Just a thought.

Again, don't fry your fingertips; let go when it gets hot.

[PRR]

> if they make them with safety lenses.

No; but they are slim enough that some Safety Glasses might fit over them.

Still clumsy for varying distances (if distances were fixed you'd just tuck cheap readers under the Safety Glasses).

The optics are fascinating (if you are into that).
http://www.adlens.com/img/Our_Technology_v2.pdf
(Ironic that the company is about better vision and the PDF is laid-out so bad it is hard to read.)

Surprised that I can see tree-tops *better* with the Adlens than with my precription lenses. This form of Adlens has four surfaces. Generally the more surfaces, the worse the image due to surface loss. This can be controlled with anti-reflect coatings (the blue haze on a camera lens) but these aren't coated. I assume it is because I can tune for 234 feet exact, instead of the infinity-20' assumption in prescription.

Being able to come in from the trees and work at the computer is interesting. Actually my "office" pair is compromised for similar fuzz at infinity and at 30", and I don't usually switch glasses. But at infinity that is fuzzy enuff that I don't like to drive at night (I switch to the far pair). With the Adlens, I can be far-focused well, sit, turn knobs, and be near-focused. It is not as quick as having the other pair at the PC. But sometimes they aren't.

They have another technology with two flexible surfaces and a fluid pump. Pump to desired focus. However because eye-docs have a lock on the market, they are only sold through professionals who make the setting and then break-off the pump. Dandy for on-the-spot replacement of busted glasses. Not handy for variable-distance work (unless you can talk the doc out of fixing the strength; and I dunno how long the pump would last in regular working). Costly. And intensely ugly.

[MrStab]

how do you manage to teach/inform me of things even from my juvenile attempts at humour, Paul?!

$19.95 doesn't seem shabby at all for what you've described. i have astigmatism as it happens, so they're probably not for me. shame, as the ones in the PDF link look quite discreet. i'm quite surprised you say it can out-do your 'script specs in some cases.
i wonder if all that Google Glass stuff will automate focus someday. wouldn't wanna be there for that firmware bug.

lost my glasses at a show a coupla months back, but still managed a few successful builds before i replaced them (with some headaches as a trade-off). i can't say i've ever had the need for magnifying lenses of any sort, but i only work with through-hole stuff. my vision is slowly getting worse as times goes on and my brain cells are substituted with psychoactive compounds.

i also have red-green defect colourblindness, so i'm screwed when it comes to reading resistor values. i'd say sorry for starting this derailment, but eyesight narcissism is good fun.

[karbomusic]

i can't say i've ever had the need for magnifying lenses of any sort

I can see (with my glasses) just fine yet I still save myself trouble almost every single day by using a magnifying glass (hand held and one of those big illuminated ones) to double check things that are easily missed even with 20/20 vision. Just mentioning because I was just noticing the builds that were working first try after I had found several macroscopic issues that I knew I would have never noticed without that (now required) step of up close verification.

[R.G.]

At the risk of being repetitive, the Harbor Freight magnifying visor for $5 is an almost incredibly good value. If you're younger than 30 and don't otherwise need correction, you're probably fine, but go to the magnifiers sooner rather than later. You'll like it.