Help! Soldering on a new board

[Rigormortis]

I'm having a hard time getting the solder to stick to the pads on my printed circuit board. The pads have a white film, which \i thought was ready to solder. But I've found a lot of cold solder joints after I started in.

Does this white film need to be removed?

OK. I think my iron wasn't hot enough to get the wire itself hot. It seems to be working now with the white stuff intact.

[zhyla]

I'm not familiar with this but my guess would be a wipe-down with acetone would take off any manufacturing residue or anti-corrosion goo.

[olddawg]

I'm not familiar with this but my guess would be a wipe-down with acetone would take off any manufacturing residue or anti-corrosion goo.

That and use a little liquid flux. Maybe even rough up the pads a little with a pencil eraser, matchbook cover, fine emory cloth, etc. Don't use steel wool unless it is a naked board and you can whipe it off afterward.

[wyomingrocks]

soldering

Make sure you have a good tip on your iron. Soap and water on the solder side have always worked fine for me with a toothbrush. Defintately make sure it is dry before applying any current to it of course. Alcohol and acetone as mentioned, are the only things I have ever used.

[Enzo]

I don't know about your boards, but some "bare copper" boards have a film over the copper, I guess to keep it shiny untik you buy it. This interferes with the soldering. The small "experiementer" boards I bought at Radio Shack were like this. I always sanded the boards copper side a little before soldering. Steel wool would work, but I don;t allow the stuff in my shop. I use Scotch Brite - the green plastic pads used like steel wool for cleaning pots and pans. It is abrasive enough for the job, but softer than the copper so it doesn;t sand through it. 400-800 grit emery cloth also would work.

[Rigormortis]

Thanks. I definitely will clean the next board. I had to go over each pad and heat it up again. I may have overheated a germanium diode that way.

I have a nicer digital soldering station now, which helps keep the tip the right temp. What temperature should I be using for populating a brand new board?