"Polish" solder mask

[morten_beta]

So, I'm doing a proper PCB build. I've cleaned the excess flux of with alcohol (94%), and now the solder mask looks dull — joint looks dynamite though. Is there any way to restore the shine? I've googled high and low and no dice.

Any suggestions?

Best,
Morten

[cloudscapes]

electronics cleaner/solvent.

[UKToecutter]

I used to clean edge connectors with what I new as an architects eraser.
It's a very tight bundle of fibreglass in a tight binding.
Polishes bare copper or gold to a lovely bright finish.

[davent]

I used to clean edge connectors with what I new as an architects eraser.
It's a very tight bundle of fibreglass in a tight binding.
Polishes bare copper or gold to a lovely bright finish.

Found these... ?
http://www.eraser.com/products/fybrglass-brushes-erasers-product/abr3c-eraser-coarse-abraser-brush/

May just need to get the residual alcohol/flux crud film off the board, more , lots more alcohol?

If the boards aren't too crazy big, you can pop cooled flux off with a tool like a dental pick, then just brush the dust away.

[greaser_au]

More likely it is a thin film of residue left from the flux. wipe with a soft bristle brush or lint free tissue (maybe with some clean alcohol) to see if it cleans up.

In the factory we used loads of isopropyl alcohol.  A "dirty wash" scrubbed with a short stiff brush was followed with a "clean wash" with a long soft brush. there was always some residue after the dirty wash. the clean would soon become the dirty, the dirty would get thrown out, and a new clean wash poured.

In the repair, or one-off enviroment, the boards would be held on edge, the joints scrubbed, with the IPA (and the dissolved flux) running into a folded paper towel on the bench, then flushed with a little clean IPA.

I think the trick is to not let the solvent/flux dry on the board!

david

[CodeMonk]

These can work wonders cleaning.
They work great for some of those NOS parts with dirty leads.

[duck_arse]

May just need to get the residual alcohol/flux crud film off the board, more , lots more alcohol?

..... followed by a round of Trololo. I was wondering what Poland had to do with solder masks, and then I read the thread.

greaser, do you remember the good old days of Freon?

carry on.

[greaser_au]

greaser, do you remember the good old days of Freon?

ooh yes.... pouring 20 litre drums of Freon TF into the Hollis evaporative cleaner! 

I accidentally dropped a board into the cold side - leaned in to retrieve it and discovered what 'lack of oxygen' meant.    (I cannot believe people do this to enhance their bedroom fun!)

One of the girls washed boards with heatsink paste on them- this contaminated everything so the conformal coat would not stick - and it took a week to find out due to QA/test cycles so we had many contaminated batches.

david

[davent]

May just need to get the residual alcohol/flux crud film off the board, more , lots more alcohol?

..... followed by a round of Trololo. I was wondering what Poland had to do with solder masks, and then I read the thread.



carry on.

I wandered in to find out what masked infantry men from Poland had to do with building pedals. Winter onset dementia...
dave

[PRR]

> cleaned the excess flux of with alcohol

94% booze? You can drink that stuff!! Use something stronger.

Acetone is legal, evaporates clean, and is far safer than many other solvents (such as tri-chlor).

[greaser_au]

Acetone is legal, evaporates clean, and is far safer than many other solvents (such as tri-chlor).

We tried TCE in the evaporative cleaner once, just once...  those triple-row Vero-style connectors really are a *pain* to desolder from doublesided boards...

david

[anotherjim]

greaser, do you remember the good old days of Freon?

[/quote]

Phew, I'm not the only one. All these years I've thought it was just me that single handed destroyed the ozone layer.

White Spirit

[duck_arse]

greaser, do you remember the good old days of Freon?

ooh yes.... pouring 20 litre drums of Freon TF into the Hollis evaporative cleaner! 

david

the what now? a machine? nooooo, we had a 20l drum cut in half, on a table under the windows. dirty freon on the left, clean on the right. and as for QA, erm, well, I think I saw it over there   -------->

Xyzol (other than that, its properties are unknow? really?) - was this the last name in the chemicals book, and what ever happened to it? where does xylene and toluene come on these lists, flammable and poisonous, unusable?

[greaser_au]

The IPA wash was done in a dedicated fume cupboard (a fume *room* actually) at least - not just under a window!

after 5 years of winding coils, they discovered that the wire enamel gave off cyanide fumes when soldered - and moved the coil winder machine into another fume cupboard (laminar flow bench? nice name - same crappy environment!)...   I guess the girls must have complained about how unattractive I was

david

[PRR]

> Xyzol ... what ever happened to it?

I dunno. Never heard of it, Google isn't helping. It may have been a proprietary brew.

There is Xylol, a generic name for a mix of xylenes, which are hydrocarbons found in or cracked from crude oil, can be used as a toluene/toluol substitute. Toluene is plastic model airplane glue, causes nasty short-term poisoning, but has less long-term effect on the body than good old benzene. However a can of "Xylol" may contain some of these or other similar chemicals; you really do not want to be around it.

Acetone (like ANY oil-solvent) will mess with your brain (nerves are insulated with fat) but otherwise is generally safe to be around.

It is almost as flammable as gasoline, so don't spill it under sparks or pilot-lights.

Of particular note: Acetone and Hydrogen Peroxide (some of you use this) mixed creates a highly unstable explosive compound, acetone peroxide. Yes, bomb-stuff, but SO unstable that it is more likely to kill you than your target.
https://en.wikipedia.org/wiki/Acetone_peroxide#Accidental_byproduct