PCB lacquer....

[therecordingart]

I'm building some preamps, and I want to protect them as good as I can. Is there a lacquer or shellac that I can get at Home Depot, Walmart, Sears, or any of those places? I spray the pcb before I solder right?

 

[asm]

i got this stuff from 3M once called "conformal coating". it went on thin and invisible and is waterproof and condensation proof.
check it out.


t

 

[Rob Flinn]

I use acrylic lacquer, like you use over car spray paint.

 

[therecordingart]

And do you spray before or after soldering?

 

[Kev]

conformal coating ... as stated above

after soldering
after fully cleaning and inspecting the solder joints
... and after it is fully operational

I use folded up paper towel and various solvents (my special mix) to rub clean and polish the under side of the board

you can clearly see any less than perfect solder joints

then when happy with the look and feel I then spray

 

[Brian Roth]

Why spray anything????? Ampex, Neve, et al never did that!

I guess if your gizmo is being used on a USA Navy ship or submarine, with salt-spray, it could be an issue....and most recording studios now forbid cigs.

Bri

 

[gyraf]

Kontact-chemie SK20 laquer, solderable, for protection of the copper traces. Applied before soldering, makes it much easier to solder.

Jakob E.

 

[rafafredd]

what about C37? :razz: Should sound awesome!!! :razz: :green:

 

[chrissugar]

Great sugestion Rafa. Nothing compares to C37. :grin:

chrissugar

 

[Kev]

[quote author="Brian Roth"]Why spray anything????? Ampex, Neve, et al never did that![/quote]their boards where soldered throughout ... ALL tracks had solder all over
... can think of the word for it
you know what I mean

Many home etched boards are left with much copper exposed.
risk for corrosion

ALSO

high humidity or water danger environments ... the spray covering UPs the reliability greatly.

HOWEVER it has been argued that for some RF and very Hi Voltage stuff it could be a bad thing ... capacitance and conductivity etc of the spray


Kev boards are sprayed
Kev boards are good
smug mode
:green:

 

[therecordingart]

Gyraf,

Do you know where I can order that stuff? I live in the U.S. I'm finally developing/etching nice boards, but now having a hell of a time with the solder running all over the place and screwing up my boards. Will the spray keep the solder from doing this? I obviously don't have this problem with professionally made boards...only mine.

 

[gyraf]

The stuff is named "Flux - SK10":

http://www.kontaktchemie.dk/Produktoversigt/flux_sk_10.htm

http://www.crceurope.com/csp/web/contact.csp?lng=3&country=BE

Jakob E.

 

[Emperor-TK]

Another product availible in the US is called Humiseal. It sounds similar to what Jakob describes. You could also plate your traces with electroless tin, which is a very easy process and is probably a similar protection scheme to what Neve and Ampex did. I suspect that Neve used a wave solder technique, but getting tin or tin/lead on the copper by whatever means is really the point. FWIW, I would never leave bare copper on a board that I made. Copper is very easily oxidized and IIRC, is not "capped" by it's oxidation layer and will continue to oxidize through the bulk over time.

Regards,
Chris

 

[Svart]

i always tin my traces. usually nothing more needed.

 

[therecordingart]

I bought Humiseal 1B73 from Krayden....man does this stuff kick ass! Soldering is now a breeze...no runny solder!

Next I'm going to try electroless tin.

 

[CJ]

like the clown say, make Sure your done soldering or you will have a frustrating time soldering thru that gunk.
do it every day unfortunately on the high imp. stuff.

 

[therecordingart]

It is completely solderable....just like the stuff that Gyraf was talking about.