Board cleaning

[worker0]

Ok friends, I managed to get NaOH.

I get 1KG relatively cheap.

How much watter to use on 1KG, and hoe long boards to sit inside?

 

[niks neims]

I've had success removing green solder mask by boiling it in 5% NaOH drain cleaner, not even that long - for about 30-40 minutes... I did it in stainless steel pot. Worked great. I've heard you could probably leave it for some time without applying heat (few days?) And it would work too.

Be careful, though, it's very nasty stuff (especially hot), it'll make soup out of your flesh, eyes or anything you'll spill it on. It's what criminals use to dispose of bodies... Actually it's one of those chemicals I'm very surprised isn't more regulated - I can get a 25 kg bag of 100% flakes (well, technical grade), dirt cheap, no permit no nothing.... Once, for fun (I had this soap making phase, lol) I boiled (in any hardware store off the shelf drain cleaner 5% stuff) a piece of raw pork meat - all dissolved in to slurry., Scared me a little...

But basically just use 50 g flakes for 1 litre of water and you'll be close enough, be careful, though, it makes heat when dissolving in water - if you add just a little of water it can start to boil, splatter all around, you don't want that. You should be ok with 5%, but still be careful....

Edit:
a) shame on you for not listening to experienced members regarding safety.
b)why do you want to remove solder mask? From those boards in your pictures, I doubt there is any gold plating under there and even if there is - its microscopically thin (ENIG), gold value about few cents per cm2 - you need m2's of this kind of plating to get few grams worth, from the boards in your pictures - you won't be able to see anything....

 

[jarlowski1]

I've had success removing green solder mask by boiling it in 5% NaOH drain cleaner, not even that long - for about 30-40 minutes... I did it in stainless steel pot. Worked great. I've heard you could probably leave it for some time without applying heat (few days?) And it would work too.

Be careful, though, it's very nasty stuff (especially hot), it'll make soup out of your flesh, eyes or anything you'll spill it on. It's what criminals use to dispose of bodies... Actually it's one of those chemicals I'm very surprised isn't more regulated - I can get a 25 kg bag of 100% flakes (well, technical grade), dirt cheap, no permit no nothing.... Once, for fun (I had this soap making phase, lol) I boiled (in any hardware store off the shelf drain cleaner 5% stuff) a piece of raw pork meat - all dissolved in to slurry., Scared me a little...

But basically just use 50 g flakes for 1 litre of water and you'll be close enough, be careful, though, it makes heat when dissolving in water - if you add just a little of water it can start to boil, splatter all around, you don't want that. You should be ok with 5%, but still be careful....

Edit:
a) shame on you for not listening to experienced members regarding safety.
b)why do you want to remove solder mask? From those boards in your pictures, I doubt there is any gold plating under there and even if there is - its microscopically thin (ENIG), gold value about few cents per cm2 - you need m2's of this kind of plating to get few grams worth, from the boards in your pictures - you won't be able to see anything....

Sorry Niks this was too funny: you going on and on about your story and then teaching him how to use the chemical safely and then WHAM!! Shame on you for not listening to the safety advice given above. Made my day


On the subject though I am at a loss for words as how to get worker0 to heed the warning that many of us here have given him on many different threads he has started, and just read the forum about what type of scrap he is trying to refine. The forum search tool located in the menu tab is extremely helpful but he will not listen. He continues to go on his way without actually studying about what he is doing.