soldering iron wattage recommendation ??

Johnny · Post by **Johnny** » Sun Mar 01, 2009 7:45 pm

Looking for a soldering iron wattage recommendation.
I have a 30 watt that I was planning on using but, after receiving the kit the other day and seeing some of the smaller
components, I am afraid that the 30 watt might be a bit too much.

Thanks

MartinM · Post by **MartinM** » Sun Mar 01, 2009 10:14 pm

I use an Antex XSL 25W (www.rapidonline.com code 85-0848) but the 18W will be perfectly OK as well. your 30W is probably a little bit too high.

...but the key thing is the bit size for a V4 kit - the 2.3mm that comes with the Antex irons is like a poker for the surface mount components - you need something no bigger than 0.5mm (Rapid code 85-0531)

HTH
Martin

Johnny · Post by **Johnny** » Tue Mar 03, 2009 1:24 am

Found the packing for my 30 watt, and it is supposed To be 750 deg. F how might that compare to a 18 or 25 watt temp wise ?

I looked up the Antex and the size looks pretty handy.

Weller WLC100,,, this thing caught my eye
http://www.toolbarn.com/product/weller/WLC100/

Post by **brentp** » Tue Mar 03, 2009 4:20 am

We have this Weller model- not cheap but works very well:

http://www.testequipmentdepot.com/welle ... wesd51.htm

Johnny · Post by **Johnny** » Tue Mar 03, 2009 12:44 pm

brentp
The range on the Weller was 350F to 750F

What temp do you run the Weller at when you are working on a board?

Thanks
John

MartinM · Post by **MartinM** » Tue Mar 03, 2009 1:01 pm

Soldering iron/tip temperature should relate to the solder being used - and there should be a datasheet or value given for each different solder. Have a browse of
http://www.rapidonline.com/Tools-Fasten ... der-Fluxes
to see the example different temps for different solders.

Soldering iron wattage should relate, essentially, to how big a thing you want to solder i.e how much heat you need to put into the joint itself and the two components e.g one end of a SMT resistor being soldered to a relatively isolated PCB pad will need less heat (wattage) than the same resistor being soldered to a ground or power plane.

Then there's tip size, which needs to be considered in terms of physical size to get into the places you need to and its ability to provide the heat without cooling down too much.

Simple innit

There are different types of joint in the V4 kit - my 25W iron with a 0.5mm bit is overkill for almost all of them except the ground tag of the regulator (the one on the other side of the three legs) and the right angled MOLEX connector, where it is just about right.

Post by **brentp** » Tue Mar 03, 2009 6:33 pm

Hi John,

With 63/37 solder I run it about 375C / 700F. As Martin points out, the temperature is dependent on the size of the joint you're soldering, so about 700F on this particular iron strikes a good balance for all of the components in the kit- about 1-2 seconds soldering time for the medium sized kit components. This iron changes temperature quickly, which is a nice feature.

Johnny · Post by **Johnny** » Thu Mar 05, 2009 12:27 pm

Thanks for all the help
I picked up a 15 watt iron, and it worked great, a little trouble with the large tab on theLM2937-5.0 Voltage Regulator in the power supply kit,
just a bit too much for the little iron.

Right now I am soldering the resistors for the rev limiter, and they really seem to suck the heat up.
My 30 watt (cheep iron) is having trouble.

Johnny · Post by **Johnny** » Thu Mar 05, 2009 9:58 pm

All buttoned up and it communicates with pc.

MartinM · Post by **MartinM** » Thu Mar 05, 2009 10:15 pm

Excellent news! Keep us posted....