Desoldering components

for bbc micro/electron hardware, peripherals & programming issues (NOT emulators!)
Boydie
Posts: 117
Joined: Sat Oct 24, 2015 8:25 am
Location: Sunny Wigan

Desoldering components

Postby Boydie » Tue Sep 12, 2017 5:18 pm

All this messing around with defunct ICs has led me to think I need something better for desoldering components.
I'm currently using my soldering iron and an unheated solder sucker, which is usually just about adequate but sometimes tends to struggle (solder solidifies in the time between removing iron and applying sucker).

Are there any better tools for the job?

Is http://cpc.farnell.com/duratool/d01849/ ... dp/SD01702 this any good, or are there alternative methods which work better? I've tried desoldering braid in the past and found it to be awful.

RobC
Posts: 1735
Joined: Sat Sep 01, 2007 9:41 pm

Re: Desoldering components

Postby RobC » Tue Sep 12, 2017 5:29 pm

I use one of these: http://uk.farnell.com/miller-abeco/39466/desoldering-gun-antistatic/dp/1689398

It has a flexible nozzle so allows you to get right into to the joint while the iron is still providing heat.

I bought it based on a recommendation on here and find it to be extremely effective. (The only weak point is the plunger which would be better if it were made of metal. I had one break after *very* little use but Farnell replaced it for free.)

The other thing to do is to add a little new solder to the joint as this helps the old stuff to melt.
Last edited by RobC on Tue Sep 12, 2017 6:59 pm, edited 1 time in total.

cmorley
Posts: 220
Joined: Sat Jul 30, 2016 7:11 pm
Location: Oxford

Re: Desoldering components

Postby cmorley » Tue Sep 12, 2017 6:19 pm

The vacuum solder stations work well like the Duratool D00672. If you use braid then you need quality stuff with decent flux in or to flux the cheap stuff before you use it. Then it works fine. As Rob said adding fresh solder helps a lot as this helps conduct the heat to get a proper melt when you go for the desolder attempt - regardless of desolder method. I also bought some of those desolder needles (really cheap from china) which have their uses on occasion.

User avatar
danielj
Posts: 5136
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester

Re: Desoldering components

Postby danielj » Tue Sep 12, 2017 6:55 pm

The other thing is, if you've got a replacement IC ready to go and you're not fussed about losing the original, just snip it off then remove the legs separately, it's much easier than trying to get the whole thing out in one go!

I use a combination of soldamop, flexible nozzled pump and hot air depending on what I'm trying to do. With that lot I can't ever quite justify spending on a through-hole desoldering tool.

-> to add, when using a pump, you keep the iron on the pin and suck whilst still heating.

d.

crj
Posts: 145
Joined: Thu May 02, 2013 4:58 pm

Re: Desoldering components

Postby crj » Tue Sep 12, 2017 7:08 pm

danielj wrote:when using a pump, you keep the iron on the pin and suck whilst still heating.

Yes, this.

User avatar
Lardo Boffin
Posts: 605
Joined: Thu Aug 06, 2015 6:47 am

Re: Desoldering components

Postby Lardo Boffin » Tue Sep 12, 2017 7:18 pm

I have one of these and found it to be very effective and relatively cheap.

https://m.ebay.co.uk/itm/Solder-sucker- ... Ciid%253A1

They also sell the replacement silicon tips as they don't last forever.
BBC model B 32k issue 4, 16k sideways RAM, Watford 12 ROM board, Retroclinic Datacentre + HDD, matchbox co-proc, Viglen twin 40/80 5.25" discs, acorn cassette
BBC model B 32k issue 7, turboMMC, Opus Challenger 3 512k, Pi 3 coproc, Acorn 6502 coproc

bprosman
Posts: 142
Joined: Sun Mar 29, 2015 10:27 pm

Re: Desoldering components

Postby bprosman » Tue Sep 12, 2017 7:26 pm

With this one I stripped 2 Acorn Atoms to the bare bone (PCB) :

http://www.aoyue.com/en/pro/default.asp?id=345

Regards, Bram

User avatar
1024MAK
Posts: 6679
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...

Re: Desoldering components

Postby 1024MAK » Tue Sep 12, 2017 7:30 pm

Part of this is the cost/benefit consideration.

If you are regularly doing repair work, then the expensive gear is of benefit, as it speeds up the process of fault finding and fixing.

But if you are only doing it occasionally, for double sided boards, just cut the pins of the suspect chip as near the body as you can. Clean the solder side of the board to remove contamination and dirt. Apply some new solder to the joint, then remove the old pin/leg and finally use a desolder pump / solder sucker to clear the through-hole ready for the new socket or component.

If you really want to easily remove chips, another way is to hold onto the chip with some long grips. Then use hot air to evenly heat up the pads (for through-hole, on the underside of the board). When all the solder has melted for all pins, the chip will almost fall out. But this is something you have to practice, as it's possible to overdo the heating and cook something if you are not careful. Also if there are nearby parts that may be affected, you may need a heat shield.

Mark
For a "Complete BBC Games Archive" visit www.bbcmicro.co.uk NOW!
BeebWiki‬ - for answers to many questions...

User avatar
grobda
Posts: 101
Joined: Tue Apr 23, 2013 1:46 pm
Location: Glasgow

Re: Desoldering components

Postby grobda » Tue Sep 12, 2017 9:00 pm

I use a duratool desolder station - zd-915, seems to be a slightly older model than the current one.

It's a godsend for removing ICs, I fix the odd arcade PCB and this invariably involves removing IC's, preferably intact, as some aren't easily replaced. Definitely paid for itsself in time saved alone.

I've used hot air removal on scrap boards too but it risks warping the PCB or lifting tracks if you're not careful.

dominicbeesley
Posts: 401
Joined: Tue Apr 30, 2013 11:16 am

Re: Desoldering components

Postby dominicbeesley » Tue Sep 12, 2017 11:36 pm

grobda wrote:I use a duratool desolder station - zd-915, seems to be a slightly older model than the current one.


I'm gonna get me one of those, I just saw a video of it and it looks perfect. I got a desolder/sucker thing off ebay a few weeks ago and one word...garbage!

D

User avatar
paulv
Posts: 3554
Joined: Tue Jan 25, 2011 6:37 pm
Location: Leicestershire
Contact:

Re: Desoldering components

Postby paulv » Wed Sep 13, 2017 7:04 am

Boydie wrote:All this messing around with defunct ICs has led me to think I need something better for desoldering components.
I'm currently using my soldering iron and an unheated solder sucker, which is usually just about adequate but sometimes tends to struggle (solder solidifies in the time between removing iron and applying sucker).


In the meantime, you could change your technique for removing solder from the board. I simply don't remove my iron and get the pump as close as possible (usually over the solder and touching the iron) before then hitting the button on the pump. This method is pretty effective and I only need to do minimal revisits to any given pin.

My solder pump is one of those Japanese ones with the replaceable silicone tips so damage to the tip of the pump isn't a big deal.

The hardest pins to desolder are the ones connected to the ground plane which acts as a heat sink. The remedy for this is to increase the temperature on the solder station so the heat doesn't dissipate as fast from the pin.

Another cheap alternative is to use solder wick to suck up the solder from the pin. This can be a very effective way of desoldering items without a pump, be it manual or automatic.

Paul


Return to “hardware”

Who is online

Users browsing this forum: Bing [Bot] and 14 guests