2. tech-talk
  3. 123446-68555

Do I really need Desoldering for replacing resistors/caps?

To replace such as resistors or caps.  Do I really need to get desoldering gun?   I was thinking to replace some of resistors and caps on ARC LS7.  The cheapest I seen was Hakko desoldering FR300-05 for $265, not sure if it worth it to buy it and will only use it once for this LS7.
Thank you,
eddy1

Showing 2 responses by kijanki

kijanki's avatar
kijanki
4,452 posts
 
You could get manual desoldering pump for $4.50 or solder wick 
http://www.parts-express.com/Search.aspx?keyword=solder%20wick&sitesearch=true
Kester #66/285 is a proper solder - eutectic Sn63/Pb37 is the best for small electronic parts while 285 flux is mild and can be left on the board.
kijanki's avatar
kijanki
4,452 posts
 
Older solder oxidizes and stops wetting leads/pads.  In order to obtain good solder joint you need flux.  Flux serves two purposes - it cleans surface and prevents oxidation. Flux can be delivered with new solder containing flux or flux syringe.  If you don't have flux syringe you have to add substantial amount of new solder ending up in excessive amount of solder.  That's why you have to remove existing solder first  (In process of replacing SMT parts old solder is often left on the pads but then new flux from syringe is added before soldering).  Yes, you can make it easier by cutting leads of old components, but you have to remove old solder.
More to discover