Recomended Iron wattage/ how to not burn the crap out of your parts questions

[deadspeaker]

I bought one of those 5 piece soldering iron kits form radioshack and have built two non-functional fuzz faces (allthough I'm gonna get the 2nd one working in a few days cause i figured out what went wronge...) I found out that the iron is 30 watts. Isn't that a bit much? Could this be killing my resistors or caps or whatever? I'm using transistor sockets for the transistors so i don't kill them. I never get a measurement from the unpolarized capacitors with my DMM set to ohms. Is this because they don't do ohms or something? So thanks in advance for the answer to my wattage question.

[foxfire]

30 watts shouldn't be too hot unless you're leaving it on the parts for a long time. i'd say that 25 watts is the most common iron. as for resistors and caps it would take holding the iron on them for a good while. with that said keep on using sockets for tranny's and ic's.

[deadspeaker]

Oh that's reassuring. Thanks for the tips. Do you think it is too hot for leds? A friend wants me to put them on his psp(I hate video games but he says he will pay me so.....)

[foxfire]

it shouldn't be. if you're new to soldering i'd suggest getting some cheap spare parts and practicing. you want to be able to get in and out with the iron. it shouldn't take more than a few seconds to get a good joint. a good clean tip helps also. i also suggest keeping an old toothbrush and rubbing alcohol on hand for cleaning the flux off the board.

[petemoore]

I bought one of those 5 piece soldering iron kits form radioshack and have built two non-functional fuzz faces (allthough I'm gonna get the 2nd one working in a few days cause i figured out what went wronge...) I found out that the iron is 30 watts. Isn't that a bit much?
 I prefer 15w for general board wirings, but mainly because the tip is narrower.
 Could this be killing my resistors or caps or whatever?
 Doubtful, to go from heat damage would probably be transistors and diodes, then copper pads.  
 ...Then after that, caps. in order of 'heat-weakness' [or so my experiences would say], resistors being the most resistant to heat.
 With a clean, tinned tip, then just enough solder on the pad as the iron presses/touches onto the solder/pad/joint leads to 'flow' heat transfer, then time for heat transfer [about a second or two], then try adding solder, little bit, little bit, try to let the solder grab the hot copper, adding cold solder cools the copper...with the correct timing and waiting a bit to add more solder, you should be able to control heat [iron] and cool [pads, leads, solder] so that the copper of the joint starts grabbing the solder sooner, then once it's 'grabbing', flow just enough [try small amounts, inspect, re-flowing after cooling is generally a quicker heating process because the heat flows right across through the solder, copper touching copper has limited heat transfer contact area, hence takes longer for the heat to cross].
 In this way [just a touch, let it flow] the joint can be properly flowed in less time which means less heat goes builds up inside the cap.  
 I'm using transistor sockets for the transistors so i don't kill them.
 "cool !'
 I never get a measurement from the unpolarized capacitors with my DMM set to ohms.
 DMM's and analog meters measure DC resistance, caps are DC blocking. Caps have increasing resistances as AC frequency increases, X value cap makes X amount of resistance at 100Hz, Less at 200hz, at O.O Hz [DC], it blocks all current.
 Caps are 'expensive' to measure, so I just go by the numbers and compare them, often socketting or otherwise swapping input cap values.
Is this because they don't do ohms or something?
Capacitors have increasing resistance to lower frequecies, as freq drops, R increases.
So thanks in advance for the answer to my wattage question.
Perhaps googling or Wiki-ing 'Resistor' and 'Capacitor' will provide links which go to component description pages, a general recommendation of reading then reading the other links.
 There is a lot, but it is easier to read through than type out...the 'quality' and density of information from the reads outdoes by LY's what i can type out.
 Might seem like a lot of sorting to find what piece you want, but you'll probably need much of what you're sorting through, sooner or later.

[soulsonic]

I think tip temperature is more important than wattage. I do the majority of my soldering at around 370^o to 380^oC - sometimes I may go as high as 400^o or as low as 360^o. That's generally around 700^o to 750^oF. The physical size of the component and the type of solder used is usually the main determiner for me.
I highly recommend an iron with control over the temperature of the tip, there's many ones available in the ~$50 range that are really decent.

[Arfman]

I think tip temperature is more important than wattage. I do the majority of my soldering at around 370^o to 380^oC - sometimes I may go as high as 400^o or as low as 360^o. That's generally around 700^o to 750^oF. The physical size of the component and the type of solder used is usually the main determiner for me.
I highly recommend an iron with control over the temperature of the tip, there's many ones available in the ~$50 range that are really decent.

What's most important to me is the quality of the solder. Overnight the quality of my solder joints in both tube amps and stompboxes increased significantly. The difference - Cardas Quad Eutectic solder. I use a RadioShack 40 watt for most of my tube amp work and a 20 watt for most of my stompbox work. I kid you not, it really doesn't even matter what the wattage or heat is as long as you can safely get the tip to the joint...the Cardas flows so quickly and evenly you just don't need to hold it on there very long. Once I grabbed a 70 watt Weller gun and intentionally heated and reheated a joint. Took over 10 times before the joint started looking dull...

Changing to this solder accounted for the most significant improvement in the quality of my builds...

[soulsonic]

Kester 44

Nuff said

[the_random_hero]

I'm using a Goot 46W pencil, and I've found that I've killed less components with this than I did with a 25W generic iron from Jaycar. It's temperature-controlled to 320 degrees, which most people find to be too cool, but it's perfect for how I solder.

[petemoore]

  I've had unclean' boards prevent solder from taking properly to the metal surfaces..
  Aggressively rubbing the copper pads with very clean cotton [even paper] can visibly shine them, and cause the solder and heat to 'take', and take much more quickly and predictably.
  I'm sure some use fine sandpaper, whatever...shining the copper before attempting to flow solder is always a worthwhile effort, most easily done with a clean, fresh board.
  Any kind of crud, finger oil's a good one, insulation that somehow got in there, dust, oxide etc. should be thuroughly cleaned as it prevents easy soldering.
  Also the resistor tape [if your pulling resistors from a resistor packs sticky tape], takes Some rubbing or clip the very end off, don't want anything glue-like in the solder works.
  Many things can get on fingertips when handling...tools, boxes, switches etc., washing hands once in a while during a build can prevent oils from coating component leads you're placing.
  The oil jumps and moves across the entire surface area heated when heated. the only way to turn it to carbon enough for the solder to work around it is...heating...cruddy joints [any tiny amount of non-metal substance] = the solder won't 'take' right.

[Paul Marossy]

I use a 25 watt pencil iron. Works perfect for me with Kester 60/40 solder. 

[PerroGrande]

True confessions...  I've never owned a fancy soldering station, nor even a particularly fancy soldering iron.  My current iron is a 25watt pencil iron.   I've been soldering stuff for almost 40 years, so I've got a bit of practice (sheesh, I just realized that I've been soldering stuff for almost 40 years... now I feel old!).

In my experience, there are several things that help with successful soldering:

1) Good technique.  Practice, practice, practice. 

2) Good solder.  The solder *does* matter.  A few years ago, a local company donated a ton (literally) of solder to my employer.  Included in this bountiful feast were all sorts of brands, compositions, thickness, etc.  It also ranged from total crap to amazing.  Interestingly, though, a co-worker (with soldering skills equal to or better than mine) and I compared notes.  While we agreed on the "crap" designations, we did not select the same as our favorite.  Find something that produces good results for *you*.

3) Clean tip.  When I was learning, I did not pay a lot of attention to keeping the tip of the iron clean.  My dad could solder perfectly with a tip so dirty you could hardly find it... I cannot.  I keep the tip of the iron very clean while I'm working.

4) Clean board.  If you can work with a clean board, you'll probably get better results.

5) Decent soldering iron.  Okay -- I don't have a great soldering iron (and probably never will).  However, the damn thing has to work.  I've had several that didn't deliver heat to the tip (even after replacing the tip).  These ended up in the junk pile.  I had one that would get hot about a centimeter up from the tip.  Worked great for tinning wires, etc, but was useless for working on a circuit board.  Trying to use this to work on PCBs would have ended badly.

6) When designing your own board, know your limits.  If you know that you tend to have trouble with certain types of solder pads or spacings, try to avoid them in your pcb design as much as possible. 

7) Did I mention practice, practice, practice?

[Gus]

The good ones are the temp controlled ones.  Yes they cost more money.