Remove solder from within Humble Pi holes

[chorlton2080]

Hello

Whilst I have been successful in removing a header connector from the Humble Pi board (via the destructive approach), I now have solder collected in the holes of the board. I can't get close enough with a solder pump to remove them to allow a new extra tall pin header to be inserted prior to soldering.

Does anyone have any practical advice to offer? Many thanks in advance.

[FTrevorGowen]

It may be possible to (carefully) drill out the blocked holes with a suitably fine "pin drill" in a "manual chuck/holder". Use of a "manual" device rather than a "motor driven" one is advisable since that reduces the chances of also drilling out any "through plating". Whether it's worth the effort depends upon the number of "blocked holes" and how many of them are for pins that you need to use for your project etc. It might just be simpler to just purchase a replacement board.
Trev.

[KenT]

Have you tried heating it up and banging it on the desk. Also de-solder wick. Use a very fine bladed watchmakers screwdriver as a drill.

[Burngate]

If you can get at both sides of the hole, then apply iron on one side, a length of suitable-thickness tinned-copper-wire on the other. Push the wire through and it'll pull the solder with it

It's best to use a long length of wire - after the solder's removed, the rest of the wire will come through no problem - and make sure it's pretty straight as any kinks can wreck the through-plating

[PiGraham]

Rather than sucking you may be able to blow. A lens puffer might do. Melt the solder then give it a puff but be careful where the hot solder goes!

[fuffkin]

Here's a few options:

- Solder wick is definitely a good bet as previously mentioned.

- If you can still use the solder sucker, try adding more solder to the hole which can sometimes help get the solder sucker to work, and then the surface tension pulls all the solder out. Don't expect instant results, you may have to repeat this many times, before you hit on it.

- If the holes are connected to large copper areas then two soldering irons can help to get it hot enough (if you have two soldering irons that is). If not try warming the board up with a hot-air gun i.e. normal DIY paint stripper type.

- Hot air gun to heat up all the holes and then hit on the side of a bench as previously suggested.

In all cases, there's no magic bullet, all will take a lot of fiddling before you finally get all the holes clear.

Best of luck!

[mikerr]

When I did that I used a straightened paper-clip held in pliers
-while melting the solder push the paper-clip through, then pull it out
-the solder will then be on the paper-clip, not in the hole.

[mahjongg]

melt the solder, then push a wooden toothpick in, and let the solder cool.

another method for holes that are not too small, melt the solder and gently knock the solder out. If the boards contain any crystals, knock only very lightly.

[Twinkletoes]

Go to a jewellers tools supplier (e.g. http://www.cooksongold.com/) and buy a 0.5mm drill bit and a pin vice. A pin vice is the most amazing tool you'll ever buy. Basically a drill chuck in a bic biro with a spinning plate on the end. You use it one handed putting the plate in your palm and holding the chuck with your finger tips. You can get 1/10 turn accuracy, and it doesn't slip so you can drill very accurate holes by hand.

[Burngate]

... a 0.5mm drill bit and a pin vice...

The trouble with that is that you risk destroying the through-hole plating.
If it's only double-sided, and what you're putting in the hole can be soldered both sides, then you're alright, but if there are layers in the middle that should also be connected, you've no chance.

[PiGraham]

... a 0.5mm drill bit and a pin vice...

The trouble with that is that you risk destroying the through-hole plating.
If it's only double-sided, and what you're putting in the hole can be soldered both sides, then you're alright, but if there are layers in the middle that should also be connected, you've no chance.

I second that. Any force or cutting around platted-through-holes (PTH) holes is risky.
I'm not keen on Solder wick either, because it requires more heat and pressure that alternatives. Heat + air, blow or suck, is the safest option with an iron.

[mahjongg]

agreed, never try to drill out plated holes of a multi layer board!
Never felt the need to do so either, although it can be difficult to get all the solder out, especially if the plated hole is internally connected to a ground plane.
In the most difficult cases, when solder wick doesn't work (not even with flux paste) I found that knocking the solder out almost always works best. In contrast even commercial desoldering stations (that heat the hole, and use suction to suck out the solder) tend to be more troublesome than this trick. So heat it, and give it a good bang on the table would be my tip.

Also, for reworking you are allowed to use leaded solder! So reflow the hole with 60/40 tin with a resin core, and try again if you are having troubles.

[Lob0426]

I have never tried it, but wondered if heating the solder then a quick burst from a computer air can might clear the holes. It is going to make quite a mess though. Might want to throw down an old towel or something!

Any reservations about trying this?