Small Sodium Perfulfate measurements. HELP!!!

[brokenstarguitar]

I need some help to convert Sodium Persulfate. I usually use Ferric Acid from RadioShack to etch my boards but I decided to try something different. I bought Sodium Perfulfate from Small Bear and don't want to make a whole gallon, just enough to etch a few boards. Let's just say 4 Oz. How much Sodium Perfulfate do I add?

[Ben Lyman]

How much do you have to add to make a gallon?
There's 128 oz. to a gallon if that helps

[brokenstarguitar]

1/2 pound (225g) of crystals to 1 gallon of water.

[PRR]

Put ALL the facts (known and un-known) together.

Don't expect people to do your research, especially for facts you already have in hand.

What does the Bear tell you to do?? (I can't squint the fine print in the image.)

Ah, the instructions are at the Injectorall site:
http://www.injectorall.com/instructions200.htm
"One half-pound container is mixed with one gallon of distilled or filtered water."

> Let's just say 4 Oz.

OK. And how many Oz. in a Gallon?

Ass-uming US Gallons, 128.

So a Gallon has 128/4= Thirty-Two 4 Oz gulps in it.

So you want 1/32 of a half pound.

You could just mark the jar into 32 divisions, take one division. 32 divisions just means marking half, and then half of each half (quarters), half of each half (eighths), half of each half (16ths), half of each half (32nds).

Or scale:

Pound is 16 Oz weight. Half pound is 8 Oz weight. (Note that Oz of liquid is NOT Oz of weight except for specific liquids.)

8/32 is 1/4 Oz weight.

Postal scales won't read that small.

One US Penny (post-1982) is 0.0882 Oz. 1/4 Oz is 0.25 Oz. 2.83 Pennies is your 1/4 oz.

The instructions suggest you can go stronger for faster etching.

So balance a ruler across a pencil. Put a cupcake cup on each side. Put 3 cents in one side. Shovel powder in the other until it just balances. Add to 4 Fluid Oz of pure water.

[Ben Lyman]

Ya. What he said... easy peasy 

[brokenstarguitar]

Put ALL the facts (known and un-known) together.

Don't expect people to do your research, especially for facts you already have in hand.

What does the Bear tell you to do?? (I can't squint the fine print in the image.)

Ah, the instructions are at the Injectorall site:
http://www.injectorall.com/instructions200.htm
"One half-pound container is mixed with one gallon of distilled or filtered water."

> Let's just say 4 Oz.

OK. And how many Oz. in a Gallon?

Ass-uming US Gallons, 128.

So a Gallon has 128/4= Thirty-Two 4 Oz gulps in it.

So you want 1/32 of a half pound.

You could just mark the jar into 32 divisions, take one division. 32 divisions just means marking half, and then half of each half (quarters), half of each half (eighths), half of each half (16ths), half of each half (32nds).

Or scale:

Pound is 16 Oz weight. Half pound is 8 Oz weight. (Note that Oz of liquid is NOT Oz of weight except for specific liquids.)

8/32 is 1/4 Oz weight.

Postal scales won't read that small.

One US Penny (post-1982) is 0.0882 Oz. 1/4 Oz is 0.25 Oz. 2.83 Pennies is your 1/4 oz.

The instructions suggest you can go stronger for faster etching.

So balance a ruler across a pencil. Put a cupcake cup on each side. Put 3 cents in one side. Shovel powder in the other until it just balances. Add to 4 Fluid Oz of pure water.

Thank you. 

[PRR]

me> So you want 1/32 of a half pound.

There's also the dorm dope technique.

You buy a half-pound of weed.

And a box of baggies.

And find a double-LP album.

Take the record out and play it.

Pour the dope on the spread album.

Find a pack of cards. Ace of Spades works best.

Cut the pile into two equal halves.

Cut each pile in half again. Keep it equal or some of your customers will complain.

Keep going until you have 32 piles.

Put each pile in its own baggie.

The half-pound was 8 Oz.

8 Oz cut in 32 splits is 1/4 Oz per split.

Since this is etchant, not dope, don't smoke it. Put one baggie in 4 Oz of water. This is exactly the recipe Injectorall gives.

[peterc]

Laffed a lot.....

[smallbearelec]

How much Sodium Perfulfate do I add?

About a rounded teaspoon to four ounces of water. I'm glad to say that my notes at the end of this article in How-Tos

http://diy.smallbearelec.com/HowTos/DirectPCBoards/DirectPCBoards.htm

match Paul's figures.

[digi2t]

Paul Heisenberg 

[KazooMan]

This does not need to be exact.  Just put some water in a plastic tray, dump in a bit of the persulfate, and follow with your board.  Keep the solution and reuse it.  If the etching gets to be too slow just add some more persulfate.  Plastic food storage containers with snap on lids are great for this.

[greaser_au]

me> So you want 1/32 of a half pound.

There's also the dorm dope technique.

Oh the things  I missed going to night school...

david

[tubegeek]

me> So you want 1/32 of a half pound.

There's also the dorm dope technique.

You buy a half-pound of weed.

And a box of baggies.

And find a double-LP album.

Take the record out and play it.

Pour the dope on the spread album.

Twenty years later, the seeds are still wedged in the fold.

Extra bonus points if it's an original pressing of Bob Marley's "Burnin'" album with the embossed burlap texture, for just this purpose.

Oh, and don't let your lowlife roommate have the key to the closet if you want to turn a profit.

Oh, and sometimes the lowlife roommate is YOU.

True story: MY lowlife roommate up and joined the Navy. WTF?