Desoldering?

[MD Willington]

I like the ghetto solder sucker there...I suppose a shopvac could be rigged up to do the same, the only thing is that moving a lot of air across the heated area will cool it down pretty quick.

MD

[mcel]

Whatever you do, don't use a drill to clear out holes, even if you think it's smaller. These are multilayer boards with internal planes, for at least ground and +V, in addition to the tracks you can see on each side. The holes are plated through and arranged to make contact where necessary with the internal tracks. Drilling could destroy these connections.
Mike

[kc8adu]

i watched an idiot drill solder out of a board with an isotip pc drill attachment.
warned him that if the slightest bit off center he would damage the throughholes.he did it anyway rather than having me take the board home and doing it right.
after his "repair" the board had several new problems.
took me 5 hours of rework to fix that mess.
he had spun out the throughholes in 9 places and soldered heavy enough to hide them.
customer fired the idiot on the spot when i told the boss what their resident "tech" had done.
mitsubishi wanted 3k for that board.
and they had payed 9k for the machine(wire edm) knowing it had issues.

Whatever you do, don't use a drill to clear out holes, even if you think it's smaller. These are multilayer boards with internal planes, for at least ground and +V, in addition to the tracks you can see on each side. The holes are plated through and arranged to make contact where necessary with the internal tracks. Drilling could destroy these connections.
Mike

[stretch0069]

Someone PM'd me about drilling out the holes. I said it was a bad idea. He/she did it anyway (I guess) and tried converting me to drilling as well! Oh well. Some people.

I realize that not everyone has access to a good soldering/desoldering station or the money to buy one, but I have access to an old (at least 10 years) Pace PPS-200C. So far I've replaced two sets of caps and a ZIF socket. It worked awesome. No problems getting the holes clear. If only I had one two years ago.

Yes....I said ZIF. Ok....I was bored and didn't have anything new to calculate (see 'ton of caps' )

[mcel]

Back in my mainframe computer development days, hundreds of years ago, we were pretty proud we'd reached a 12 layer central processor backplane. But I see manufacturers now talk of 20 or more layers... Now on that sort of board, you really don't want to mess with the plated thru holes!

[ncdave]

Re: moby solder sucker

I need an SPDT "Y-valve" rather than a simple SPST on/off valve, so that I can switch the tip back and forth between atmosphere and vacuum, but I can't seem to find such a valve. :-( Does anyone know where I could get one?

I've learned that they are called L-type 3-way ball valves. They may also be called multiport valves, diverter valves, or selecting valves.

Brass & stainless L-type 3-way valves can be bought on eBay starting at about $10.

Here's a company which sells many types of plastic 3-way ball valves:
http://www.usplastic.com/catalog/def...arentcatid=870

Note that some of them are spec'd as "not for vacuum." I'm no expert, but I suspect that, in general, ball valves are probably better for controlling pressurized fluids than for controlling vacuum, because the pressure presses the ball against the port, to help make a tight seal. This might be particularly true with "floating ball" designs. However, I think one of these would probably work well for the Moby Solder Sucker.

If I understand correctly, there are two broad categories of 3-way ball valves:
L-type are "break-before-make." For this application, that's what we'd want.
T-type are "make-before-break."

Wikipedia, though worse than useless for anything even slightly controversial, has some good info on this, here:
https://en.wikipedia.org/wiki/Ball_valve#Multiport

Here's a diagram, from a valve manufacturer on Alibaba:


And here's the Moby Solder Sucker, needing one of those valves: