Soldering Iron: Too Hot for Circuits?

[Grateful Ted]

All, I am about to build a Versacopter with the Naze32 Acro. One of the build videos cautions against using too hot of a soldering iron as it could damage the board circuitry. My soldering iron (a fairly small one from Radio Shack) doesn't have a thermometer on it like the fancy one that Josh uses but it does say 20 watts. Will this get the job done without causing harm?

Thanks!

 

[pressalltheknobs]

If it's a 20W/40W iron intended for electronics (the pencil style and not the gun style) it will probably be fine for soldering pins to input/output pads so long as you have a pointed tip. Just make sure to clean your bit with the wet heat resistant sponge, use flux cored solder and tin things first so you are not spending more time than necessary on each pin. Prolonged heating can damage the pads

It probably will not be so good for soldering or de-soldering existing components on the board since non-leaded solder is used. It has a higher melting point and a non temp controlled iron may take too long to melt it which allows the heat to spread affecting nearby components.

 

[razor02097]

20W is perfectly fine for board soldering. Although you might struggle tinning and soldering the larger power wires with it.

 

[stay-fun]

Too low power also isn't good, because you need to touch the board for too long, allowing heat to spread. Like the others suggested, if it's a non-controlled iron for electronics, you'll probably be fine.

 

[quadsview]

For those of us that do have a temperature controlled soldering iron, what temperature should you run it at.

 

[razor02097]

For leaded solder on circuit boards and surface mounted components or small servo wires I run it at 600*F. If I'm doing through hole soldering I crank it up to 650* or 700*F. If I'm tinning and soldering larger wires together I use a large tip and crank that baby all the way up...or get my 150W solder gun.

 

[Paul-H]

Another factor is the size of the tip

I use 3 Antex 25w Irons with a pointed tip for light work a 5mm tip for general work and a 10mm tip for heavy work.

Its the size of the tip that governs how much heat it retains and makes available so in my case not all 25w irons deliver the same amount of heat even though they are all 25w Irons

Scientifically incorrect I know but in practical use it is correct

 

[ZoomNBoom]

Too low power also isn't good, because you need to touch the board for too long

This. You're not likely to damage the PCB because your iron is too hot, you're far more likely to damage it because you hold the iron too long on to the pcb, and you're more at risk of doing that if the iron is not hot enough (especially with lead free solder on the pcb) and/or if it doesnt have enough heat capacity. If your iron doesnt have much heat capacity, it will actually cool down while the PCB absorbs the heat, and that is what you have to avoid.

 

[Wishy]

Hey
I plan on building a versacopter for xmas, and will probably buy the unsoldered version of the naze 32(too cheap for the gr18, and the shipping), and if I like rc with the 280 class, it'll be used often, but not too much
This is a mid- budget not the cheapest but definitely not getting a hero5 on it, so tools also should be kept to a reasonable budget.
Sould I get the cheapo xt60 powered soldering iron from hk, or shoul I get something else from Amazon or Ebay, a small one like this whitch comes at a price
http://www.banggood.com/TS100-Digit...ron-Station-Built-in-STM32-Chip-p-984214.html
Thanks

 

[Snarls]

Sould I get the cheapo xt60 powered soldering iron from hk, or shoul I get something else from Amazon or Ebay, a small one like this whitch comes at a price

Check this iron out on Amazon. It is fairly cheap and I have heard it works very well. Weller is a well known brand.

 

[Wishy]

Thanks! I'm guessing the power adapter is US?
I know i should not buy a really cheap one, seems important to have a good one!

 

[Craftydan]

Thanks! I'm guessing the power adapter is US?
I know i should not buy a really cheap one, seems important to have a good one!

It is important to get a good one, but it doesn't have to be expensive.

While Weller is a good name brand (If I were outfitting a professional lab, I'd lean that way for the "I can't afford for it to break" reliability) IMO, it's a bit too expensive for fine soldering for the hobbyist. While that $40 Weller Iron is a good deal for what it is, I'd also mention it's not thermally controlled, it's power controlled, so for what you're wanting to avoid burning out boards/parts, it may be a finicky tool.

A thermally controlled iron has a sensor in the iron constantly tracking the temperature of the iron and adjusting the power output on the fly. Sitting in the stand it will draw one power level. Touch it to something to solder, as the temp drops and the iron automatically cranks up to the needed power to keep the temp at the set point.

This means you can have a 100W+ iron capable of reaching temperatures that melt through the printed circuit board if left to run at full power . . . but if you set temp is to just above the solder's melting point, the iron never gets any hotter than that temp. Better still, with the lower soldering temp (backed by the "when I need it" power) a VAST majority of the parts you solder around can now tolerate the temp -- you won't burn out pads on the PCB, and it becomes MUCH harder to burn out components.

So if that iron is unsuitable since it doesn't maintain a safe temp for you, what's a better option?

dunno about you local plugs, but look at this one:

http://www.hobbyking.com/hobbyking/store/__19241__Soldering_Station_with_Adjustable_Heat_Range_with_EU_Plug.html

It's a knockoff of a Hakko 936 (an older but reliable iron, and Hakko is a good brand), but it's a good iron for the price. It's a fairly good copy of a solid design, and the corners YiHua cut are fair. 60W thermally controlled should be MORE than enough for most any fine soldering safely, with the power to do medium sized battery wires with a touch of patience.

One caveat I'd make for the YiHua 936 -- buy an original Hakko iron tip. The soldering tip that comes with it is cheap, but all soldering iron tips are intended to be replaceable. Plan ahead to replace the original tip, and buy an genuine tip from Hakko when you order the iron.

 

[Wishy]

Seems like a good idea, especially with them bein back in stock in HK
I'm trying to limit the online stores from whitch ill be ordering, so how about this tip? http://www.banggood.com/5pcs-900M-T...ko-936937-Soldering-Station-Etc-p-982740.html
Thanks for thr tip

 

[Craftydan]

Those will fit that iron, but the cheap price and lack of marking on the shaft screams knockoff.

A genuine tip will be etched with the brand and part number and tend to run between $5-15, depending on the tip and the source. It'll also be made of better materials, something you can't easily gage even with the new tip sitting in your hand. It's your call, but I wouldn't go cheap aftermarket/knockoff on the tip, even if it meant spending almost as much on it as the rest of the iron.

 

[jhitesma]

Geniune Hakko tips are definitely nicer to solder with...but...I would advise being careful with them on clone irons. I have a 936 clone from CSI (http://www.circuitspecialists.com/station-60.html is the closest they currently carry...mine is an older model I got 10 years ago and has been replaced in their lineup with a upgraded version.)

I'd always used the generic tips CSI sells to go with it to good results. But a few years ago I picked up a couple of geniune hakko tips at a hamfest from a dealer. They worked GREAT...but...they got stuck on my heating element and I was no longer able to change tips. When I finally HAD to change tips it broke the ceramic heating element effectively ruining the element and the tip. Thankfully my iron came with a replacement heating element (though it required soldering to install and I couldn't find my spare 40w iron so I had to borrow a friends iron which was a horrible way too hot and unregulated sears beast better for doing stained glass work than electronics.) so I was able to repair it.

So while I agree that the genuine tips are great and are wonderful to solder with. You do have to be careful with them on knockoffs. If they don't fit easily over the heating element and there's ANY resistance...don't use them. Get a different heating element or tip and save the tip for when you have an element it fits on better. The generic tips from CSI I've had very good luck with and they're almost as nice as the genuine hakko tips.

Of course if you don't change tips very often it's probably not as big of a deal. But I go back and forth from working on SMT stuff and soldering heavy gauge wires so I sometimes need a larger or smaller tip. (Though to be honest even on SMT it's easiest to use the largest tip you can get away with due to the thermal energy it can hold I usually use a 2mm chisel tip even on very tiny components, just takes a bit of dexterity to use the right edge of the tip without hitting anything you don't mean to.)

 

[Craftydan]

Hmmm . . . . good to know.

I hadn't run into any clearance issues with my tips, but I can see the tolerances being looser on the knockoff heating element. If that's the case -- and seems to be -- then it'll vary from iron to iron whether it can take the real tips or not. The Hakko tips do slide on with less slop, so it makes sense the cheaper tips are spec'ed a hair wider.

Meh. If the cheap tips are that cheap, the longer better life isn't worth the risk of having the unlucky iron. You'll just have to be willing to ditch them early and often.