I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

I was looking on ebay and it looks like there are some affordable "Hot
Air" soldering stations. I really don't want to drop a grand on one for
hobby work but I would like to be able to do more of this type of thing.
So, are the ones that you see new for $150.00 to $200.00 any good? Can
you get parts and different tips for them, and should I stick with one
brand over another?

Here is a link to a couple pictures of the board with the CPU that I
replaced.
http://www.amiga.org/modules/myalbum...id=3657&cid=13
http://www.amiga.org/modules/myalbum...id=3656&cid=13

Thanks for any suggestions and Happy New Year to everyone here.

Jeff
(jeff at newsguy dot com)

Jeff wrote:

I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

I was looking on ebay and it looks like there are some affordable "Hot
Air" soldering stations. I really don't want to drop a grand on one for
hobby work but I would like to be able to do more of this type of thing.

snip

I built my own; it works well and has adjustments for temp and airflow.
Perhaps this is an alternative to a purchase. Please see
http://www.cybertheque.org/homebrew/smt-rework-tool

Regards,

Michael

Jeff wrote:
I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

I was looking on ebay and it looks like there are some affordable "Hot
Air" soldering stations. I really don't want to drop a grand on one for
hobby work but I would like to be able to do more of this type of thing.
So, are the ones that you see new for $150.00 to $200.00 any good? Can
you get parts and different tips for them, and should I stick with one
brand over another?

Web-Tronics has some affordable units that look like re-branded
Xytronic. Howard Electronics has the real Xytronic units (also
mostly affordable). I've purchased equipment from each and
haven't had any issues.

Hoods are often interchangeable but do check the dimensions,
of course.

You also may not need as many hoods as you imagine. There's a
good tutorial on using hot air over at Sparkfun where they mostly
use a single pipe hood. Don't miss the videos.

Finally, also check out the ChipQuik system. If you don't do a
lot of rework then it may be a better route. It really does work;
I've used it myself on some 0.5mm TQFP packages and was able to
reuse the part and the board (no clipping!).

http://www.web-tronics.com/soldering...-supplies.html
http://www.howardelectronics.com/xytronic/products.html
http://www.sparkfun.com/commerce/hdr.php?p=tutorials
http://www.chipquik.com/

--
Rich Webb Norfolk, VA

In article Lg%dj.7598$cq5.1521@trndny06,
Jeff wrote:
I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

I was looking on ebay and it looks like there are some affordable "Hot
Air" soldering stations. I really don't want to drop a grand on one for
hobby work but I would like to be able to do more of this type of thing.
So, are the ones that you see new for $150.00 to $200.00 any good? Can
you get parts and different tips for them, and should I stick with one
brand over another?

I'm in the UK and bought one of these:-

http://cpc.farnell.com/jsp/Tools,+Storage+&+Handling/Desoldering/Rework+Stations+&+Tools/DURATOOL/ZD-939A/89-3912/displayProduct.jsp?sku=SD01139

which I'm sure is available elsewhere. Remarkable value for money. I know
of a repair shop where one is in heavy use and it seems to have survived
for a couple of years.

Only thing I dislike about it is it runs when you first power it up and
scares the life out of you - if it's on a master circuit like in my
workshop. I find it a decent addition - but not a replacement - to my
conventional de-solder station.

--
*Real men don't waste their hormones growing hair

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

I'm in the UK and bought one of these:-

http://cpc.farnell.com/jsp/Tools,+Storage+&+Handling/Desoldering/Rework+Stations+&+Tools/DURATOOL/ZD-939A/89-3912/displayProduct.jsp?sku=SD01139

Looks very similar to the Xytronic I have. Probably one factory
makes 'm all and silkscreens on the various labels. ;-)

Interesting picture on that site, though. They either got the
tool hanger on upside down or that's another one of your "we
drive on the *correct* side of the road in the UK" issues.

Only kidding, of course. Happy New Year!

--
Rich Webb Norfolk, VA

On Dec 30, 9:39*pm, Jeff wrote:
I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

Good for you! That removal can't have been easy.

There's a good removal solution that works without extra
soldering hardware, called 'Chip-quik'; it's a very low
melting point solder, you just clean, flux, add the special solder,
then the whole chip lifts up at circa 100C (which is the melting point
of the alloy).
Of course, it needs to be cleaned up before re-soldering with real
solder. The removed part doesn't need any leads clipped,
though.

Dave Plowman (News) wrote:
In article Lg%dj.7598$cq5.1521@trndny06,
Jeff wrote:
I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

I was looking on ebay and it looks like there are some affordable "Hot
Air" soldering stations. I really don't want to drop a grand on one for
hobby work but I would like to be able to do more of this type of thing.
So, are the ones that you see new for $150.00 to $200.00 any good? Can
you get parts and different tips for them, and should I stick with one
brand over another?

I'm in the UK and bought one of these:-

http://cpc.farnell.com/jsp/Tools,+Storage+&+Handling/Desoldering/Rework+Stations+&+Tools/DURATOOL/ZD-939A/89-3912/displayProduct.jsp?sku=SD01139

which I'm sure is available elsewhere. Remarkable value for money. I know
of a repair shop where one is in heavy use and it seems to have survived
for a couple of years.

Only thing I dislike about it is it runs when you first power it up and
scares the life out of you - if it's on a master circuit like in my
workshop. I find it a decent addition - but not a replacement - to my
conventional de-solder station.


Depending on how much you need to do, you can do considerable soldering
with a variable paint stripper gun. They're power controlled, so the
temp varies with air flow, but you can still do a reasonable job with
a homebrew head/baffle assembly and a thermometer.

Another thing that works way better than I expected is a Portasol butane
torch with the catalytic
hot-air tip. Works great for small stuff. If you use the hot air
or a hotplate to preheat the board, you can use the butane torch to
quickly reach the melting point and do rather large stuff. The torch
puts the heat in a small space right where you need it.

--
Return address is VALID!

In article
,
whit3rd wrote:

On Dec 30, 9:39*pm, Jeff wrote:
I just replaced a Cyrix surface mount 486 cpu this weekend with my
conventional Edsyn temp controlled soldering station. I cut the old chip
body off, cleaned the pads, and used the my own version of the "flood
and wick off" the extra method. The results were good and it works fine
but there must be a better way.

Good for you! That removal can't have been easy.

There's a good removal solution that works without extra
soldering hardware, called 'Chip-quik'; it's a very low
melting point solder, you just clean, flux, add the special solder,
then the whole chip lifts up at circa 100C (which is the melting point
of the alloy).
Of course, it needs to be cleaned up before re-soldering with real
solder. The removed part doesn't need any leads clipped,
though.

I've had good luck by adding flux, wicking all the solder I can from
each connection, and then popping each leg off its pad with an x-acto
knife. The tiny amount of solder bond that's left just breaks loose.
Part is saved and re-usable, if it was good to begin with. (If I get a
tough leg I reheat it while sliding the blade under it.)

In article ,
Rich Webb wrote:
Dave Plowman (News) wrote:

I'm in the UK and bought one of these:-

http://cpc.farnell.com/jsp/Tools,+Storage+&+Handling/Desoldering/Rework+Stations+&+Tools/DURATOOL/ZD-939A/89-3912/displayProduct.jsp?sku=SD01139

Looks very similar to the Xytronic I have. Probably one factory makes 'm
all and silkscreens on the various labels. ;-)

Yup - a bit like electric drills. Dozens of makes from one factory.

Interesting picture on that site, though. They either got the
tool hanger on upside down or that's another one of your "we
drive on the *correct* side of the road in the UK" issues.

So they have - never noticed it. ;-) Probably assembled by the art
department. ;-)


Only kidding, of course. Happy New Year!

And to you and everyone.

--
*The sooner you fall behind, the more time you'll have to catch up *

Dave Plowman London SW
To e-mail, change noise into sound.