[fajimr]

not to be confused with 'tips on soldering' ... but that question will probably follow from this DIY newbie  

I just got my weller soldering station and practice kits (one of the kits has parts to solder which are superficially fit on the pcb.  i.e. there are no holes to put the leads through.  how common is that in the electronics world?).

my question is:
The tip that came on the soldering iron is a flat screwdriver head.  Is this the most comment tip to use for the soldering required to build an AKSA?  It seems to me that a pointed tip would be a better candidate (but that conjecture is based on no experience whatsoever).

so what are your tips on tips????

[soitstarts]

Hmm, I have a Wella station and mines like a point with a bit of a flat sliced off one side.. I thinkyou can file your tip to your liking. BUT don't do it until you have comfirmation...
The soldering you mention is, once again, I think pad soldering and you do few of those on the 100w kit. It'll be good practice..

[Greg Erskine]

Here's how I think of soldering.

To do the perfect solder joint you need 4 items to come into contact at one point and heat up to the right temperature in a few seconds. Your objective is to do everything possible to make this happen as quickly as possible.

The 4 items are: 1. Soldering iron tip 2: pad 3: component lead and 4: solder (with flux). All these items can and will vary, so if you are soldering a large pad with thick component lead (i.e. fuse clips), I just a larger diameter solder and larger soldering iron tip. Conversly, if you are soldering a small resistor that will have smaller pads I'd use a smaller tipped soldering iron and possibly a small diameter solder. (On the AKSA I always use the solder supplied) If you only have one iron I would turn it down quite low for the small pads (setting 3 to 4 on my weller).

So to answer your question, I think a chisel tip is best because it comes into contact with the pad and component lead and heats both at the same time.

Also, you will notice that pad area significantly affects soldering. On the PSU PCBs you need plenty of heat to solder the spade connections nicely.

As an aside, I always solder on the pad side that is away from the track. This means the heat is transferred to the pad and not to the connecting track.

I have also noticed that single sided PCBs like the AKSA PCBs are easier to solder and require less heat than a double-sided PCB with thru-hole plating.

I have never managed to destroy a component by over heating so they must be fairly tolerant or my soldering technique is good.  

BTW: I imagine Air Supply would sound good on an AKSA?

[soitstarts]

BTW: I imagine Air Supply would sound good on an AKSA?

Sounds good.. So does Smokie  

[fajimr]

thanks soitstarts (yesitdoes) and greg for the info/tips... I'll get started with the tip I got and see where it takes me.

[AKSA]

Hi Jim,

Greg's advice is, in my experience, absolutely correct.  Some say that you should heat the workpiece - the component lead and the pad - before you add the solder, but it's all so damn quick I normally don't bother with delays and put all three against the tip at the same time.  A proper joint has a nice, glistening appearance, with no trace of white frostiness.  You can always attack a joint a second time to improve its appearance;  this changes the ratio of solder to flux.  Too much heat boils away the flux and seems to prevent proper amalgam formation, and this leads to 'dry' joints, where the adjective describes the action of the flux, making the solder 'wettable'.

I use a chisel point bit;  round, with a 1/16" flattened tip.  Before every solder operation I always 'clean' the end of the bit on a wet sponge.  This operation merely removes 'old' solder from the tip, solder whose flux has been boiled out, and prepares the tip to take a fresh load of solder, with flux in it to 'wet' the new joint.

Soldering is an art.  I think it's dead easy, but I've been doing it for more than forty years.  I'm often surprised at the work I see in the industry;  dry joints are very common, but they don't always show up electrically.  Modern industrial processes are sometimes flawed because the temperature/time/bath composition is not quite correct, and components which get very hot slowly boil away the remaining flux on the joint.  Eventually, after years of thermal cycling, these joints can go 'dry', and become non-wetting.  There is a move, particularly in EU, towards lead-free solders, and while the first products for hobbyists have been difficult to use, they are getting better all the time, although they are expensive.  The problem is that administering leaded solder does create a vapor pressure, and with your leering face a few inches above the work, there is a small but constant ingestion of lead vapor.  ALWAYS keep your face and mouth to one side of the workpiece, so you are not directly above, breathing the fumes......  That said, there is little medical risk of lead poisoning, but care is still required.

Cheers,

Hugh