[Coco] Desoldering tools

[Richard Lorbieski]

I have a PACE MBT 250 at home and at work. I find it faster to vacuum out a IC faster than to "cut and braid" or use a manual solder sucker.
But I also solder and repair electronics for a living and have 36 years of practical (paid) soldering experience.


I can de-solder a 40 pin CPU in under 5 mins and save the old chip. Steve Strowbridge and Grant Leighty video taped me at Tandy Assembly doing 6309 upgrades.

I use 3 soldering tips - the chisel is my preferred general purpose, the wide half moon bevel is for large parts, and fine tip to poke holes in stubborn solder that can't be removed with a vacuum or sucker.

Sometimes I apply new solder on old solder joints. It makes it easier to remove certain solder points.

I also use nail polish remover (acetone) and isopropyl alcohol to remove the excess flux.

CoCo tip: If you are adding a socket or replacing components. ALWAYS clip the leads. In rare cases, it's possible for a sharp lead to puncture the RF shield and cause a short.



-----Original Message-----
From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Zippster
Sent: Thursday, October 19, 2017 11:02 AM
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Subject: Re: [Coco] I've killed my CoCo3

I actually do if the IC in question is in good supply and relatively cheap.
I’d use a vacuum tool if I really wanted to save the chip, but clipping and braid always works for me without damage and is easier than cleaning and maintaining the vacuum tool for me.

I’ve seen ones where a vacuum tool had a hard time as well without cranking
the heat to the point where the board would get a little scorching too.   And they
can lift pads as well if not used correctly.  Every situation is a little different depending on the board and part in question though and it’s all really down to what works for the person doing it.

- Ed

> On Oct 19, 2017, at 9:43 AM, dwight.bazinet <dwight.bazinet at gmail.com> wrote:
> 
> Hi Ed,
> 
> I used to have a full pace kit available to me n my work lab.  I much 
> prefered the vacuum desoldering tool (not the plunger, but the vacuum 
> with the solder filter).  I wouldn't even clip the pins, it would do 
> that good a job cleaning them up.  I used just a small amount of 
> liquid flux prior to heat, and then it would melt right away an hen 
> vacuum, which also drew away the flux.
> 
> However, I cn't afford a full Pace kit at home.  I haven't ot one of 
> the cheaper stations because I don't know how well they work, so I use 
> a plunger.  If I was going to do a lot of work I would get sone liquid flux.
> 
> Do you prefer braid over a proper vacuum tool?
> 
> 
> 
> On Oct 19, 2017 9:39 AM, "Zippster" <zippster278 at gmail.com> wrote:
> 
>> Hi Paul,
>> 
>> I’m sorry it went that way.  I still consider the clip and and 
>> desoldering braid the safest way, but it is pretty important to have 
>> a soldering station where you can control the temp, and using a 
>> proper tip for the iron.  A ‘drag soldering’ type tip, basically a 
>> straight cylinder with the end cut at an angle is best (for applying 
>> heat to the braid), a chisel tip probably second best.  Having a flat 
>> surface at the tip allows for faster more accurate heat transfer to 
>> the pad and solder without excessively heating the board material.  I 
>> find the common round pencil style tips to be one of the least 
>> suitable for anything.  I use a chisel or drag type for everything.  
>> Of course that’s just my opinion and everyone has their own way of 
>> doing things.
>> 
>> All that said, it’s possible the board was degraded or just not up to 
>> par in some way which helped it fall apart on you.  It can happen.
>> 
>> If you want, you can send the board to me, I’m certain I can patch it 
>> up for you.  No charge, just take care of the shipping.  Unless 
>> someone has a motherboard with a dead GIME out there.
>> 
>> - Ed
>> 
>> 
>>> On Oct 19, 2017, at 6:13 AM, Paul Shoemaker <paulfe3 at swbell.net> wrote:
>>> 
>>> Hi everyone,
>>> 
>>> Yesterday evening I decided to replace the 6809 with a 6309 in my 
>>> CoCo
>> 3.  Although I am still an amateur with a soldering iron, I've been 
>> practicing and recently completed this same process on one of my CoCo 
>> 2 systems where I clipped out the 6809, desoldered the remaining 
>> pins, and soldered in a socket.  However, when I tried this same 
>> approach on my CoCo 3, as soon as I started using solder wick, I 
>> noticed some of the solder pads began to come off.  I don't think I 
>> was using excessive heat (same iron, same heat settings as before).  
>> Even the traces on the board began to lift up.  It became clear to me 
>> after this happened to a few pads that I had destroyed the board.
>>> 
>>> If anything I was more gentle with the CoCo 3 board than I was with 
>>> the
>> CoCo 2 board before.  It was evident that the CoCo3 board was more 
>> "weathered" than any of my other systems...  more dust and dirt 
>> inside, a lot of oxidation on the RF modulator box, etc.  It may be 
>> that this CoCo 3 spent many years in a garage or shed prior to me 
>> rescuing it from eBay last year.
>>> 
>>> Any advice on how to avoid from happening again this in the future?
>>> 
>>> -Paul
>>> 
>>> 
>>> 
>>> 
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