How to best clean out a solder hole after desoldering?
Jan 15, 2009 at 10:59 PM Post #16 of 25
Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif
Great tips !!!

Where does one buy a SS dental pick ? The local Drug mart/Wal Mart/Superstore had nothing of the kind......

Peete.



I got a set from a dentist friend of mine. I did a quick search and found several on eBay. Since you're in Toronto, there's a place called K Dental on Finch E. near Markham that sells them and also has an online site.
 
Jan 16, 2009 at 12:08 AM Post #17 of 25
You can also find these in many hardware/tool stores, not labeled as "dental picks", but simply "picks". Usually they are 3 or so in a package, with different shaped ends.
 
Jan 16, 2009 at 12:47 AM Post #18 of 25
So i've got 5 of 6 holes clean, thanks for the help! The last one is being a pain though, i've tried a desoldering bulb, wick, flux, pick... Nothing seems to be able to get the last bit of solder out of there.

Any ideas?
 
Jan 16, 2009 at 1:42 AM Post #19 of 25
Cool, thanks guys......
smily_headphones1.gif


beerchug.gif
cheers !

Aphexii try filling the hole in with some fresh solder and then try again with the vacuum bulb...sometimes this works with real stubborn ..um...holes
smily_headphones1.gif


Peete.
 
Jan 16, 2009 at 3:18 AM Post #20 of 25
You can also clean out the hole using a small drill bit. A local electronics shop sells PCB drill bits in 0.8mm and 1.0mm sizes, but hardware shop bits are just the same only cheaper.

Oh, don't use it in a drill or dremel, to much chance of damaging the board. Do it buy hand or with a pin vice.
 
Jan 16, 2009 at 3:52 AM Post #21 of 25
The picks are a great idea - also available at Harbor Freight for next to nothing ... they aren't nearly as strong as the "real thing," but that's not needed for this.

I just use braid, but there are a few pointers for those tough holes. The real problem is solder in the middle of a plated hole. You may have to attack this from both sides:

1. Add solder to the hole. Try to do this in such a way that you melt the solder caught in the deep part of the hole - before you add more solder. This makes the entire solder blob contiguous. That way when it melts, it should melt everything and the wicking action from the braid will suck it out. Otherwise, you'll just repeat solder/remove for the same blob you added each time, without clearing out the original "stuck" solder.

Note that enough solder should be added to cause a slight, but noticeable, bump above the surface of the board. This works much better than just using a little bit of solder.

2. As stated above, you may need to do this on both sides of the hole.

3. Make certain the braid is completely clean. You may have snipped off the end that was filled with solder, but trace material may travel as far as twice the length of the visible solder portion on the braid.

4. It helps to make certain the iron is hot. Also, a little dab of solder on the iron where you touch it to the braid will "jump start" the wicking action. This can be critical sometimes, because often you'll lay the braid over the hole, apply the iron, but nothing happens. "Jump starting" with a bit of solder on the tip of the iron that touches the braid will ensure good wicking right away.
 
Jan 16, 2009 at 4:06 AM Post #22 of 25
I use a good old safety pin - just match the right pin to the hole size... just be careful not to lift the pads by pulling it out after the solder cools.
 
Jan 16, 2009 at 4:16 AM Post #23 of 25
If it's that intent on staying, leave it in peace. When you go to insert the part, just hit it with the soldering iron again.

And the will therein lieth, which dieth not. Who knoweth the mysteries of the will, with its vigor? For God is but a great will pervading all things by nature of its intentness. Solder doth not yield himself to the angels, nor unto death utterly, save only through the weakness of his feeble will.

If you're more intent on getting it out than it is in staying put, quickly but very gently inserting and removing a heated drill bit should make short work of it. Push it through at least 1/2" on the other side to let the solder end up in the grooves. Better: push it all the way so the grooves of the bit go completely out the other side. If you weren't slick enough, you might need to grab the last bit with wick or a bulb, but don't do this if you still see solder on both sides or deep inside--just use the bit again. Or you could just push it all the way through--a one way journey through the through hole--but don't ask me how to hold such a hot bit that way. You could drop it, but dropping a hot drill bit full of molten lead is a dumb thing to do (tm). I used to put it in a flat wooden clothes pin and heat the tip of the bit with a lighter or... maybe a candle... I really don't remember. Wood's good because it won't suck up the heat, and is more resistant to flame than plastic. Try to choose a good quality wood, like hickory. It'll fill the room with that nice pleasant smell of burnished wood, give you a sense of accomplishment, and that sense that you're in a real work shop, and is therapeutic besides. The bit should be hot enough to melt the solder on its own. Just use the bit, not the iron, and you'll be sure. Just don't apply any pressure--the bit should almost fall through from its own weight--it really won't but you should only use the slightest pressure only to overcome the drag from the molten solder. If the solder's will is truly fantastic, and you need to try again, just push it though (gently) as far as your makeshift handle lets you and leave it to cool off. If it gets stuck even a tad after cooling off, don't pull twist spindle or mutilate not even a hair's breath, just reheat the bit near the hole. You might want to constantly twist the bit slowly while it cools to prevent it from sticking, which is why you want to get it in far enough so it's past the groove part of the bit. While not crucial, try to use a bit slightly smaller than the one used to drill the hole. You want a smidgen of wiggle room or you'll risk pulling the pad off. I have no idea what kind of bit I had, but the solder never stuck to the bit. Well, not bad enough that a metal tool couldn't get it off. All I remember is the bit was silver colored, so it was probably stainless steel, as amb mentioned earlier.

They should make a soldering iron tip shaped like that.

I still think doing nothing is the best option.
 
Jan 16, 2009 at 5:14 AM Post #24 of 25
Try heating it with a heating gun while you solder. I have a board heater at work for the really heavy copper boards. It helps out a lot when using small tips on big and heavy copper planes.
 
Jan 16, 2009 at 1:23 PM Post #25 of 25
i just add a bit of flux(and solder occasionally) and then hit it with the braid. usually works the first time.
try to avoid the ratshack braid if you can, more often than not it gives off fumes worse than flux.
 

Users who are viewing this thread

Back
Top