I have used solder irons with NEW electronic equipment but a surface mount cap is MUCH smaller than the caps in this radio (Philco 40-180)
so what kind of iron would be best 15w 20w 25w or more ?
Larger would work better since the smaller wattages would take a bit to heat up the larger leads used in older radios. I picked up a weller dual wattage unit like this one
http://cgi.ebay.com/110246354104 If you get one of these types try to get the ones with the nuts on the end (to hold the tips) rather than the ones with the allen screws.
Wattage isn't as important as the mass of the copper tip, so you can get a lot of heat into a heavy terminal quickly. Temperature control is nice so you don't burn up the tips idling. But the original soldering was done with a 100W blunderbuss, so anything will work.
I personally use a temp-controlled Weller with a rather heavy chisel tip. At work I have one just like it, with a smaller conical tip that will do surface-mount stuff.
thank all of you for the info
Looks like it is now time to get me a new iron
Some of the soldering stations are nice but the Weller dual-wattages are useful and usally have 3 or more tips. Since many makers would solder to the chassis the bigger spoon shaped tips help put some heat into the chassis area when needed. I have a few pencil types for the more intricate or tight areas but for general use the Weller dual types are hard to beat and you can pick them up quite cheaply on ebay.
After buying new Weller guns only to have them fail within six months, I gave up on Weller and started buying the 150/230 watt gun from Craftsman (Sears). They are very reliable, lasting for around three years under severe service (nearly nightly usage for a few hours at a time), and not very expensive - they are often on sale at $25 or so.
I'm a big fan of the Weller SP40 pencil. 40 watts, nice 1/4" wide flat tip. If you're patient it will even do light chassis connections. They run about $16-18 these days.
For SS work I have the SP25 with the little 1/8" conical tip.
-Bill
Me, I use the cheapie Radio Shack 25-30 watt iron(s) with pointed tips. I have used the best high dollar Wellers in the past, both fast-heating guns, & Wellers irons bench-type variable temp solder irons.Since I use a solder iron usually daily, I have found all them "disposable" when it comes to hard work "continuous every day conditions". The gun-types are sometimes too-big , to get into close corners. Steady hands requires a iron-type for close "point to point" shiny connections where other tips dont always fit easily into chassis-work.Seems the Irons just fit easier into the chassis most of the time for me. Irons of (the disposable kind)!!,... are my choice, as they all wear out as we all know. Guess it just depends on what works best for each person individually!! Thats a $24 question from the get-go!!
For the "heavy duty" chassis connections, I use the old-vintage style electric cloth-covered wire (wood handle) auto radiator repair large tip wood-handle pencil type irons. You can still find these large irons at garage-sales,etc. After they heat up about 15 mins, you can quickly make those otherwise (low-wattage irons/guns) hard to connect metal-chassis connections complete, ....FAST!! These huge vintage type solder-irons work great for removing & remounting orig filter cap ground lugs, replacing broken tube socket gnd lugs back to chassis,etc! The conical tips on these type irons are about 1/4 in in diameter! No radio chassis connect is too-tough for these vintage type "big daddy" irons!! You may only need to pull out the "Big Iron" a few times a yr, but they get the job done on "shiny" direct-chassis connections better than any competitor iron on the market today!! I collect these big Irons anytime I find one for sale. Usually pay about $1.00 for them at garage-sales,etc,in used condition. Just plug em in, if they heat, they work!!
Another option for higher heat on low wattage-irons, is too use your bench variac, and crank the AC up to about 140 vac. to the iron. Adds that extra heat to a low wattage iron indeed!! Thats about all I can add to *soldering class101* (hee hee)!!