help with Hydrochloric acid strength...

[tracidfish]

Hi

I am looking to make some copper chloride for pcb etching.

I have found an online resouce saying i need hydrogen peroxide 3% strength and hydrochloric acid (muriatic acid) 30% strength.

i can only find the acid in 10% strength. I can buy the 30% from ebay but no one near me supplies it at this strength and i relay need to get some tomorrow.

Can i use this or do I need to find the stronger stuff?

To avoid a disscussion on comparing etchants I appreciate i can use ferric chloride but i would like to try this stuff for a change.

Thanks

 

[jpanhalt]

Yes, 10% HCl will work; it will just be slower. That is the method I would recommend to you.

Hydrochloric acid can be concentrated by boiling to a constant boiling point of 108.6°C, which is 20.2% and can be used as a primary standard in analytical chemistry. I DO NOT recommend that you do that, as it is unlikely you have adequate safety measures available. 10% will work just fine.

If you can get more concentrated peroxide, it will help compensate in speed for the dilution of HCl, but again you should be fine.

John

 

[Joe G]

I got the muriatic acid at tractor supply and they had two strengths in quarts or gallons. Do you have a swimming pool store near you, its used also for cleaning pools and cement, any masion supply stores near you? have you an Agway, lowes or home improvement stores near-buy? but as jpanhalt stated "slower is better".

 

[Mosaic]

I use conc. nitric acid....diluted about 1:4 parts water.

 

[Mikebits]

I would not boil HCL without a fume hood. From MSDS: Skin contact may produce burns. Inhalation of the
spray mist may produce severe irritation of respiratory tract, characterized by coughing, choking, or shortness of breath.
Severe over-exposure can result in death.
Special Remarks on other Toxic Effects on Humans:
Acute Potential Health Effects: Skin: Corrosive. Causes severe skin irritation and burns. Eyes: Corrosive. Causes severe
eye irritation/conjuntivitis, burns, corneal necrosis. Inhalation: May be fatal if inhaled. Material is extremely destructive to
tissue of the mucous membranes and upper respiratory tract. Inhalation of hydrochloric acid fumes produces nose, throat,
and larryngeal burning, and irritation, pain and inflammation, coughing, sneezing, choking sensation, hoarseness, laryngeal
spasms, upper respiratory tract edema, chest pains, as well has headache, and palpitations. Inhalation of high concentrations
can result in corrosive burns, necrosis of bronchial epithelium, constriction of the larynx and bronchi, nasospetal perforation,
glottal closure, occur, particularly if exposure is prolonged.

 

[Pommie]

Don't boil it on your stove as even stainless steel will corrode from the fumes. If you fill in where you are from people may be able to suggest where to buy 30% HCl. Here in Aus, any pool supply shop has 30% and even some super markets stock it. As for H2O2, try a hydroponics shop.

Mike.

 

[DerStrom8]

This is exactly why I do not make my own boards. I have neither the etching equipment nor the safety equipment. It's much safer and easier to send it to a company that specializes in manufacturing PCBs

 

[Pommie]

This is exactly why I do not make my own boards. I have neither the etching equipment nor the safety equipment. It's much safer and easier to send it to a company that specializes in manufacturing PCBs

I use Ammonium Persulphate for the same reason, it's white chrystals that are non corrosive and produces a clear odourless liquid for etching with. Plus, the resultant solution is simply copper sulphate which is easily disposed of.

Mike.

 

[jpanhalt]

@Mosaic

Nitric acid plus copper will not produce cupric chloride. Where does the chloride ion come from? You might also consider this discussion of the dangers of nitric acid plus hydrogen peroxide, if that is what you use: https://www.electro-tech-online.com/custompdfs/2009/10/HH-1064.pdf

@tracidfish

When I mentioned using more concentrated hydrogen peroxide, I should have mentioned that it is quite easily made from ordinary peroxide by fractional freezing. Hydrogen peroxide freezes at a slightly lower temperature than water and a concentrated solution with water has a much lower freezing point. Thus the concentrated binary solution stays liquid while excess water freezes. If you search on the process, you will find several YouTube demonstrations. Here is just one written version:
https://forums.welltrainedmind.com/...y-tip-concentrated-hydrogen-peroxide-cheaply/

John

 

[scubadog]

This is exactly why I do not make my own boards. I have neither the etching equipment nor the safety equipment. It's much safer and easier to send it to a company that specializes in manufacturing PCBs

But not as much fun!


Thanks for the tips. I managed to find some 30% acid on my travels today.

Time to etch!

 

[gary350]

A few years ago there was a scare that terrorist would use hydrochloric acid to make bombs so it was extremely hard to find anyone selling it. Next thing you know people selling it make you sign papers and show your ID to buy it. Same thing with Ammonium Nitrate fertilizer. You can buy 40% hydrochloric acid at brick yards and some Hardware stores. Swimming pool supply sells 29% hydrochloric acid.

 

[szzuk]

Don't do this, you can learn to use eagle quickly and send the board to be made for you. The cost will be less than those chemicals, quick, safe and a lot less bother.

 

[tracidfish]

Its not as quicK - i can etch a board in 30 mins.

It doesnt cost less. For exampl the quotes I have for the project i am working on are £76 for 3 boards with a 12 day lead time. I can make them for £8 in 1 hour.

It may be less bother but its not as fun.

Etching is used for porotyping. Why wait 12 days for a prototype that may be worng?

I would advise not to tell peoplke not to do something. You should suggest why they might not do it, but never tell someone not to do anything!

 

[szzuk]

Its not as quicK - i can etch a board in 30 mins.

It doesnt cost less. For exampl the quotes I have for the project i am working on are £76 for 3 boards with a 12 day lead time. I can make them for £8 in 1 hour.

It may be less bother but its not as fun.

Etching is used for porotyping. Why wait 12 days for a prototype that may be worng?

I would advise not to tell peoplke not to do something. You should suggest why they might not do it, but never tell someone not to do anything!

You're telling me not to do something

I prototype with eagle. Etching is a skill, if you want to learn for fun then enjoy!