Cleaning a used PCB

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

envelope

Well-known member
Joined
Jun 17, 2009
Messages
707
Location
Canada
Hi, I purchased a used DIY unit(not here), and I am trying to remove the components, to clean and re-populate the boards with my new parts

 I am up against something like a hardened adhesive silicone. The builder used it instead of molex connectors at every wiring point on the board. It is not as simply removed as 'hot glue'. It is as hard as a rock.

It will not just snap off, I can't stress that enough. I've tried, and I am a veteran of the bench. Wether its silicon or something else, it has seeped into the porous board and is not coming off easily.

First, I'm going to try to freeze it like a wart , with 'cold shot'......I'll post results, after I get some cold shot.

MY RESULT: Can't wait to freeze cycle it. After stripping the board, I wailed on it with a super sharp wood chisel and a rubber mallet, luckily it is a one sided board.  
 

Attachments

  • DSC00001.jpg
    DSC00001.jpg
    153 KB · Views: 67
Heat gun?

No. You do not need a sledge hammer to crack a walnut.

Unsolder the wires using suction pump. Snap it off. End of story.


 
It is a permanent silicone construction type adhesive. I cannot get under it, not even with a scalpel.

On all of the other pcb sites  where this occurred, -prior to posting this thread-, I had already de-soldered the leads, and tried to remove the blobs with various mechanical means. I'm out of cold shot, but will get some and try that.

If it was hot glue, it would snap it off.

The new chemical bond has to be broken, the circuit board is a porous type, I'm hoping the freeze cycle will work, but I like how you think. ;D

I'll post the results, in case it is useful to someone.
 
Unless it is epoxy based glue such as Araldite or resin ( and I am sure it is not because I can see it) it will snap off.  If it is a silicon based then it will be chewy, not rock hard. I think you are being  too nice to it. Grab the damn thing with the pliers and twist it.
 
hmmm... could be two part epoxy (transparent type like 3m scotch weld), thanks for the tip, it isn't chewy, it's hard as a sedimentary rock, and my scalpel is micro thin, it should be able to cut into it. I am going to smack it with a mallet and a super sharp wood chisel.
 
two part epoxy => Acetone . I had very good results with it and a scalpel. your board may not sufer ( try before with a small drop of it on a useless coner of the board to make sure, perapps...) but surely avoid it on components you'd like to re-use (it EATS vinyl, for example...).

Laurent.
 

Latest posts

Back
Top