Can I acid etch fine lines?

[Laura Butler]

I working on a design in my head right now and part of the design is so fine that I can't blast it as deep as I want without having the mask get blasted off. My question is "can I pour straight acid on my weeded glass so that it looks like it was blasted?" I don't want any texture like you get using acid with mica.

[Larry White]

NEVER USE STRAIGHT ACID!!!!!!!!!!!!!!!

If you can't blast it deep enough, you won't be able to etch it deep enough either.

IF YOU'RE NOT EXACTLY SURE OF WHAT YOU'RE DOING IN REGARDS TO ACID WORK, DON'T DO IT!!!!

[Mike Jackson]

Laura,
Suggestion 1: Do some tests!

Suggestion 2: Consider screen printing your resist with asphaltum. It usually take two coats and you have to let the first one completely dry before trying to screen the second one. We also tamped the surface of the first coat with dry powdered asphaltum between coats to help make sure it was dry. The second coat adds the needed thickness, but it can slightly resoften the first layer as asphaltum is self dissolving. If your etching zone is small, you can screen print just a patch of an image, then brush the remainder of the background with a foam brush or even a roller. No need to make a huge screen.

Suggestion 3: Refer to Suggestion 1 and make sure you have your acid bath at the proper ratios AND you have all your safety precautions in place. Remember, using Acid is a dangerous process. Read the MSDS on the product before using it!

Mike Jackson

[Mike Jackson]

Hello all,
In an effort to keep things safe here, I am adding in some information copied from a previous post about this topic. Remember, if you use ACID, you are putting yourself at risk. Information about this topic gathered through this forum is not intended to replace proper training and education. If you use ACID, please be advised that you are doing so at your own risk and this site, nor any of its participants can be held liable if you get hurt. YOU must take that responsibility.

Below is a portion of the MSDS sheet for HF. Do a Google search for the full MSDS for Hydroflouric Acid.

Hydrofluoric Acid, P.A. 48 to 51% HF Content ACROS96155

**** SECTION 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION ****

MSDS Name: Hydrofluoric Acid, P.A. 48 to 51% HF Content
Catalog Numbers:
AC223330000, AC223330250, AC223335000
Synonyms:
Fluohydric Acid, Fluoric Acid, Hydrofluoric Acid Solution.

**** SECTION 3 - HAZARDS IDENTIFICATION ****

EMERGENCY OVERVIEW
Appearance: clear, colorless.
Danger! Harmful if inhaled. Corrosive. Toxic. May cause kidney
damage. Causes severe eye and skin burns. Causes severe
digestive and respiratory tract burns. May cause skeletal
abnormalities. Target Organs: Kidneys, skeletal structures.

Potential Health Effects
Eye:
Contact with liquid or vapor causes severe burns and possible
irreversible eye damage.
Skin:
May be fatal if absorbed through the skin. Causes severe burns with
delayed tissue destruction. Substance is rapidly absorbed through
the skin. Penetration may continue for several days. Causes severe
tissue necrosis and bone destruction.
Ingestion:
Causes severe digestive tract burns with abdominal pain, vomiting,
and possible death. May cause systemic toxic effects on the heart,
liver, and kidneys. Ingestion of large amounts of fluoride may
include salivation, nausea, vomiting, abdominal pain, fever, labored
breathing. Inorganic fluorides can be harmful. Acute exposure to
fluorine compounds can lead to digestive tract burns, and abdominal
pain. Exposure to fluoride compounds can result in systemic toxic
effects on the heart, liver, and kidneys. It may also deplete
calcium levels in the body leading to hypocalcemia and death.
Contains fluoride. Human fatalities have been reported from acute
poisoning. Fluoride can reduce calcium levels leading to fatal
hypocalcemia.
Inhalation:
Harmful if inhaled. May cause severe irritation of the upper
respiratory tract with pain, burns, and inflammation. May cause
pulmonary edema and severe respiratory disturbances. Depletes calcium
levels in the body which can lead to hypocalcemia and death.
Chronic:
Chronic inhalation and ingestion may cause fluorosis with skeletal
abnormalities. Repeated inhalation may cause chronic bronchitis.
Prolonged or repeated exposure may cause permanent bone structure
abnormalities. Chronic exposure to fluoride compounds may cause
systemic toxicity.

[Patrick Mackle]

Remember that the nature of acid etching is that it etches wider as it etches deeper, so your fine lines may eventually join before you obtain the desired depth.
Deep etching fine lines with sandblasting also creates boundaries and limitations in that the fine lines will only etch as deep as the line is wide forming a perfect "V" shape. Continueing to press deeper becomes slow resulting in the line appearing "stressed" and the resist breaking down. After that point the fine lines slow down greatly beause of the accute angle of the blasting surface AND the fact that the abrasive is being worked against itself, mostly due to the action of the grains trying to enter the depression while those before them are trying to rebound. Often times you will notice the lines becoming packed with abrasive.
Most photoresists breakdown under heat or intense localized blasting. Deep lines are best acheived by taking your time and blasting from a resonable distance and adjusting your blaster to a lesser amount of sand and more air.

Pat

[Laura Butler]

Thanks for all the info. This is nothing that I am going to jump into without much research and preparation first. I don't look to be doing in the very distant future...just starting to think about it.

Will hydrochloric acid etch...even if it takes a lot longer?