Soldering iron questions and wires

I am trying to solder wires back on the + and neg and it seems my 40w is not hot enough. Also what size wires do I need to order to replace the ones that were in the Astrolux FT03?

I am assuming you are soldering the pill end with a lot of copper or aluminium to wick the heat away.

If so try preheating the piece you are soldering, 200F, 90C should be safe, hot enough to take the load off the iron, without breaking any of the components

(Use a heat gun, oven or a hair dryer)

Ok I will try that, I ordered some new wire also.

- make sure you lift the MCPCB off the pill before you try to solder. It’ll reduce the mass that sucks up heat

- flux is your friend

- tin the solder pads on the MCPCB and the ends of the wires first

- higher heat isn’t always better. MCPCB’s are designed to soak up heat, but even with a 40w iron, you should only need a few seconds on to get up to temp.

- hopefully you’re using a temperature controlled iron of some flavor

No just a cheap radio shack one.

If you’re using lead-free solder without additional flux and a dirty tip you’ll struggle.

Make sure your tip is clean, a dirty tip will reduce heat transfer.
Make sure your clean tip is tinned, this will aid heat transfer.
For more heat demanding jobs, such as pads on a larger MCPCB, you can use a little additional flux to help the solder melt more easily.
Lead-free solder melts at a higher temperature than leaded solder so is a little harder to to work with. There are health issues associated with lead though and it is up to you to inform yourself as to the risks of using solder with lead in it, and up to you as to whether you choose to use it.

Maintaining a soldering iron tip means managing the oxidation that occurs on the tip. If you are not familiar with this it is worth reading up on it/youtubing it, it is less complicated than it sounds and will give you more control over your soldering.
Hopefully that’s a good starting point, unfortunately i do not have the capacity to give you more details on this at the moment should you need them.

Ok I feel stupid, I didn’t have any solder on the tabs. Thanks all.

Thank you

Good advice given above, I’ll just add that a wider or more blunt tip works better. The larger surface area of the tip allows the heat to transfer faster. Using a fine tip made for SMD work would make it pretty difficult to solder wires on to a copper mcpcb. The copper mcpcb’s require alot more power than the aluminum mcpcb’s in my experience especially if its already mounted to the pill with thermal paste in between. Good flux in the right amount will help.

Ok I have a fine tip in right now so I will change that out. Thank you

Definitely, you want to get in there, hit it hard, and get out, all as fast as possible.

A big chisel-point tip is a must, hit it with the flat side to cover more area, and press hard. You want all that thermal mass to melt the solder as fast as possible. A fine-point tip is like hitting a tree with a Smart Car, whereas a chisel-point tip is like hitting it with an Escalade.

The way I do it, is I’d coat the pads with solder (just enough to wet, not to form big bumps), tin the wire as well, lay the wire onto the pad, make sure the clean tip has its own little blob of solder+flux hanging off it (vs poking at the combo with a string of solder), then mash down on the wire+pad with the tip so that the molten blob of solder is what heats up everything and stays behind.

Remember the old-timey soldering irons you’d actually heat in a fire or a bed of coals? You want a slightly smaller version of that. :laughing: