Kind advice required for desoldering ? - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools

Equipment & Tools From test equipment to hand tools

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th July 2014, 08:35 PM   #11
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
1N4007 are not "very tiny"!

I use a desoldering pump. Works Ok for me, but I have never tried wick/braid.
  Reply With Quote
Old 19th July 2014, 08:48 PM   #12
diyAudio Member
 
Join Date: Dec 2010
Location: Amesbury, MA
I use the pump to get the majority of the solder up and then the braid to get the rest. After the component is out and no solder remains clean the board with 90% or better isopropyl alcohol.
  Reply With Quote
Old 19th July 2014, 09:15 PM   #13
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
if the components have actual leads - and you are trashing them - then sometimes you can just shear them at the body with a Xacto knife (eye protection!) without badly torqueing the pads - the pads are much stronger bound to the pcb when not at soldering temp
then you just mop up the leads with iron and wick after removing the part body

works for thru hole parts too with diagonal cutters for heavier leads - easier to remove just one lead from one hole at a time

Last edited by jcx; 19th July 2014 at 09:18 PM.
  Reply With Quote
Old 20th July 2014, 09:09 AM   #14
diyAudio Member
 
Join Date: Sep 2009
Location: Stavanger (NORWAY)
Quote:
Originally Posted by KatieandDad View Post
So you are trying to repair a PCB.
Best way is to chop the component leaving long legs in the PCB.
Then heat each leg and pull it out. This will be easier than trying to pull out the entire component.
Caps are a bit more tricky but I stay with the philosophy - f**k the component, save the board.
Hi and thanks and sorry for the belated reply.
House cleaning yesterday
The pcb is not broken per se ... actually the preamp is working. It is about 20 years old.
But the "upgraditis" syndrome you know ... so i decided to replace all the PS caps with newer and supposedly better ones and possibly the diodes
The leads are very tiny and short under the pcb
And with the desoldering pump i am using i have issues
I need something very very efficient that even an unskilled person can operate
I am sure that pro desoldering station are sublime ... but the cost is very very high.
i am so convinced that desoldering is the real tricky part that in the future if this will be my main hobby i could even but one of this

Click the image to open in full size.

I have already risked to ruin pcbs during desoldering
In comparison to solder with the right alloy is a joke.
So to end the pcb is fine ... for now
I have ordered another one by the way and i have put the project on hold for this ... i do not want to destroy the pcb ... traces are very very thin and delicate
Thanks a lot again, gino
  Reply With Quote
Old 20th July 2014, 09:31 AM   #15
diyAudio Member
 
Join Date: Sep 2009
Location: Stavanger (NORWAY)
Quote:
Originally Posted by Mooly View Post
Braid every time for me.
And a hot iron with a large tip that can carry the heat.
Working with SMD. How to do it without specialised tools.
Hi and thanks for the kind suggestion.
I was using this one here ... i left it at parents home in the cellar

Click the image to open in full size.
i think it was ok ... with some cleaning issues and i did not like the handle
But for the rest worked ok
I have ordered another one ... this one here

Wholesale Product Snapshot Product name is S-993A Electric Vacuum Desoldering Pump Solder Sucker Gun 220V 90W Upgrade from MT-993

Click the image to open in full size.

The desoldering is absolutely the most delicate phase for me
The pcbs especially in consumer and not professional products are extremely delicate
For me pro equipment are designed and built with maintenance in mind
Consumer products are more like decorative objects.
I have already risked to destroy the unit
From what i understand there are parts that tend to get bad with age more than others ... caps for first
I do not know the actual lifespan of a cap ... but i think that after 20 years should be replaced with possibly new and better ones
To end the tools are fundamental
When a tool is right is very difficult to make wrong actions
Thanks a lot, gino

Last edited by ginetto61; 20th July 2014 at 09:39 AM.
  Reply With Quote
Old 20th July 2014, 10:35 AM   #16
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Desoldering is a skill that needs to be learnt and so its always best to practice on some old PCB first. Discrete components leads should be freed in under a second using braid... if not then the technique or iron isn't correct. You need a large flat wedge shaped tip for best results, a pointed tip doesn't have the thermal capacity to heat the braid/joint.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 20th July 2014, 10:51 AM   #17
diyAudio Member
 
Join Date: Sep 2009
Location: Stavanger (NORWAY)
Quote:
Originally Posted by Mooly View Post
Desoldering is a skill that needs to be learnt and so its always best to practice on some old PCB first.
Discrete components leads should be freed in under a second using braid... if not then the technique or iron isn't correct.
You need a large flat wedge shaped tip for best results, a pointed tip doesn't have the thermal capacity to heat the braid/joint
Hi and i agree completely. As i said i risked already to damage some pcbs
Especially the old ones are quite delicate.
And some parts have just to go, like old one turn bias pots ... they are just ridiculous compare to new multiturn sealed ones.
And bias setting is a delicate operation ...

A lot depends on the main goal i think.
If DIY from scratch is the goal well not many desoldering activity indeed
But if repair/upgrade of old equipment is the goal i think that an investment in a decent desoldering station is reasonable.
I think that 200 USD can buy a decent one to do a job fast and clean
Desoldering must be a pleasure not a nightmare like to populate again a pcb with shining brand new components. A ten minutes work.
Then a T controlled welder cost almost nothing in comparison
Also the nozzle size matters
Thanks again, gino
  Reply With Quote
Old 20th July 2014, 11:04 AM   #18
diyAudio Member
 
Join Date: Jan 2010
I agree that there is much bad braid around, for instance the cheap stuff you get at Conrad. I use the swiss-made type, this works fine even without additional fluxer.

For desoldering I suggest a second soldering iron.
"Stereo" - desoldering is an easy way to remove SMD-parts.
  Reply With Quote
Old 20th July 2014, 11:30 AM   #19
Preamp is offline Preamp  Germany
ulti.preamp.org
diyAudio Member
 
Preamp's Avatar
 
Join Date: Jul 2008
Location: North Sea, 54.7N 8.5E
I'm also using solder wick for the 'delicate' parts. One thing I found out that works well with old (almost a little crumpled looking) or lead-free solder, and especially on plated-through boards is to re-solder the joints first, ie. apply some fresh (preferably leaded) solder. This helps to liquify the whole solder quick and thorough when you're applying the wick.
It's a little more work, but still better than ruining the board IMHO
  Reply With Quote
Old 20th July 2014, 12:58 PM   #20
diyAudio Member
 
Join Date: Sep 2009
Location: Stavanger (NORWAY)
Hi and thank you All for the helpful advice
I see that specifically designed de-soldering stations are not very popular
I wonder if the problem is only the price of what else
Thanks again, gino
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
A bit of DIY advice required john jones Headphone Systems 4 12th July 2012 07:52 AM
quad advice required johniss0001 Solid State 0 28th July 2008 11:14 PM
what kind of desoldering wick to buy? spooney Car Audio 1 26th September 2007 12:33 AM
Offset nulling - kind request of advice beppe61 Solid State 13 9th May 2007 12:47 PM
Phono input advice required Satboy Analogue Source 3 24th February 2007 06:02 AM


New To Site? Need Help?

All times are GMT. The time now is 02:52 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2