when removing a part from a circut board, should i heat the part side
or the underside? i am guessing the underside since thats where you're
supposed to solder just wanted to make sure.

also, when the part is removed should i be removing the existing solder
before soldering a new part on?

wrote in message
ups.com...
when removing a part from a circut board, should i heat the part side
or the underside? i am guessing the underside since thats where you're
supposed to solder just wanted to make sure.

also, when the part is removed should i be removing the existing solder
before soldering a new part on?

If you need to ask DON'T DO IT.

It rather depends on what type of component or PCB it is. You need
specialised tools, or certainly better tools than you are likely to have if
you need to ask.

geoff

antonlamont45 wrote ...
when removing a part from a circut board, should i heat
the part side or the underside? i am guessing the underside
since thats where you're supposed to solder just wanted
to make sure.

Assuming that you are talking about "thur-hole" components
(the ones with wire leads that go through holes in the PC
board). The technique for "surface-mount devices" is
clearly different.

Yes, you almost always melt the solder from the bottom
side and grip the component from the other side to pull
it out.

also, when the part is removed should i be removing the
existing solder before soldering a new part on?

Usually, yes.

Recommend getting an old discarded junker gadget and
practice your soldering skills before going for the real
thing.

"Richard Crowley" wrote in message
...
antonlamont45 wrote ...
when removing a part from a circut board, should i heat the part side or
the underside? i am guessing the underside since thats where you're
supposed to solder just wanted
to make sure.

Assuming that you are talking about "thur-hole" components
(the ones with wire leads that go through holes in the PC
board). The technique for "surface-mount devices" is
clearly different.

Yes, you almost always melt the solder from the bottom side and grip the
component from the other side to pull
it out.

In doing so you must make sure the iron is on the joint long enough to melt
the component side solder joint too, otherwise pulling the component out
will pull the through-hole plating with it, and/or the pad and attatched
track.


Gareth.



also, when the part is removed should i be removing the existing solder
before soldering a new part on?

Usually, yes.

Recommend getting an old discarded junker gadget and
practice your soldering skills before going for the real
thing.

On Fri, 06 Jan 2006 11:45:09 -0800, antonlamont45 burbled:

when removing a part from a circut board, should i heat the part side or
the underside? i am guessing the underside since thats where you're
supposed to solder just wanted to make sure.

also, when the part is removed should i be removing the existing solder
before soldering a new part on?

If the board has tracks on both sides then use a good quality
solder-sucker, heating & sucking from the from the oppsite side to the
component, before you start to pull on it. (Solder braid isn't very good
for this as it needs too much heat). You may need to apply more solder to
get the flux to soften the joint sufficiently. If you don't use a
solder-sucker first then you run the chance of permenantly damaging the
PCB by ripping the top track off. You can usually get away without on
single-sided PCBs.

ICs are sometimes better removed by carefully cutting through all the pins
with a sharp knife then taking the pins out individually, especially on 40
or more pin packages.

On a double-sided PCB you can use the solder sucker again, after removing
the component, to clear the holes properly (iron on one side, sucker on
the other). That makes it a lot easier to fit the new part.

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info
Web: http://projectedsound.tk

wrote in message
ups.com

when removing a part from a circut board, should i heat
the part side or the underside?

If that's where its easiest to melt the solder, yes.

i am guessing the underside since thats where you're supposed to solder
just wanted to make sure.

BTW, if you're desoldering parts, there's a helpful tool called a "solder
sucker" or "solder pump".

also, when the part is removed should i be removing the
existing solder before soldering a new part on?

It's good to start out with a joint that is as clean as reasonably possible.

http://www.kpsec.freeuk.com/solder.htm

http://www.interq.or.jp/japan/se-inoue/e_solder.htm

http://www.elitecaraudio.com/tips/ca...ldering1.shtml

lol, thats what i thought to myself too when i started to consider
doing it.

however i couldn't afford to pay someone else to do it.

thanks for your replies--i have finished my soldering project with
great success!

i finished my project with success! i used solder braid to remove
excess. i have a solder pump also but found the braid better for this
application.

thanks for your help everyone!

wrote in message
oups.com...
i finished my project with success! i used solder braid to remove
excess. i have a solder pump also but found the braid better for this
application.

thanks for your help everyone!



There are solder pumps that work well, there are solder pumps that are worse
than useless. Similarly there is good and bad solder braid.

My solder pump has a squidgy black flexible rubber tip that doesn't burn at
all, and it works well.. Chemtronics No Clean Solder Wick is also a product
that does what it is supposed to.





Gareth.

In article , "Gareth Magennis" wrote:

wrote in message
roups.com...
i finished my project with success! i used solder braid to remove
excess. i have a solder pump also but found the braid better for this
application.

thanks for your help everyone!



There are solder pumps that work well, there are solder pumps that are worse
than useless. Similarly there is good and bad solder braid.

My solder pump has a squidgy black flexible rubber tip that doesn't burn at
all, and it works well.. Chemtronics No Clean Solder Wick is also a product
that does what it is supposed to

My Weller pump has a tip which is difficult to keep clean and tinned. If
it isn't right, the joint has trouble heating, model WRS 3000.

I would get a pen with liquid flux. Braids can be reflowed with the liquid
flux, and is great for boards also. The flux is just alcohol and flux. I could not be without it!

greg