SAFETY DISCLAIMER:
First and foremost, this process involves HARMFUL, CORROSIVE CHEMICALS WHICH CAN KILL YOU if used improperly. Adequate safety protection to prevent skin contact is necessary, and I do not take any responsibility for any personal or property damage incurred by the processes detailed in this tutorial. Safety goggles, vinyl full coverage gloves, full coverage clothing, and a fully protected work surface with a plastic barrier is necessary. DO NOT ATTEMPT the process outlined in this tutorial with any less than these minimum safety materials.
INTRODUCTION:Given the number of inquiries about the subject, I'd like to share a brief tutorial to achieve acid etched patterns on lightsabers. I have recently incorporated this technique into both the internal and external surfaces of some of my sabers, and have found it to be a unique way to enliven a saber design. I encourage safety-minded individuals and sabersmiths to try this technique for themselves. I'd enjoy seeing what others can produce! Of course, there are many other methods and chemical solutions which can be used to achieve an etched surface, but the process below is simply what I use as my personal preference for my particular detailed applications.
"Horus"
GLOSSARY:"Acid Etching" : For this tutorial, I will use the term "Acid etching" to summarize the process where an acid is used to literally dissolve metal, in this case the aluminum on our lightsabers. The term can imply many different processes in the art-, jewelry- or metal-working worlds, but for our purposes this condensed summary is sufficient.
"Masking" : The process of covering a particular saber part with clear packing tape. The mask resists the acid so that the aluminum underneath it is unharmed by the acid. Masking is essential to protect all areas where you DO NOT want the acid to touch. A good example is the threads on MHS parts.
"Acid Resist" : Acid Resist encompasses a couple differing methods of masking, but essentially the goal is always the same, to block the acid from affecting masked areas. PNP Blue is a material onto which you can print a pattern and then transfer onto your part via an iron or oven. 500 Degree Resistant Sharpies can be used to draw a pattern directly onto a saber body surface, but I prefer "Masking" as my technique because it ensures a perfectly straight edged border every time without the need for touching up with paint, with other Acid Resist techniques often do. Still, these techniques do have advantages in certain applications (for example, repeatable or symmetrical patterns like on a run of Satele Shan sabers...).
"Hand Scribing" : After masking a part, "Hand Scribing" is the process of cutting out and then removing areas of packing tape where you DO want the acid to eat into the metal surface underneath it. This process produces, in reverse, the eventual acid etched design or pattern.
MATERIALS:While there are several chemical mixtures which can be used for acid etching, my tutorial will focus on readily available ferric chloride.
1) Safety Goggles
2) Vinyl gloves (must be a material completely impervious to ferric chloride)
3) Full coverage clothing
4) A work surface fully protected by plastic or vinyl sheeting (trash bags, etc).
5) A large plastic tray (tupperware works great) which is large enough to cover at least half of the part in acid.
6) A large plastic bucket of cool tap water, large enough to completely immerse the part after being etched.
7) Sandpaper with grits from 320, 400, 600, 800, 1000 (go up to 2,000 grit and highly polish if you plan to seal the acid etched pattern using a translucent powder coat afterwards)
8 ) #0000 Extra Fine Steel Wool
9) Mineral Spirits or Acetone and a microfiber cloth to clean the part before etching
10) Super fine Sharpie pen
11) X-Acto knife
12) Ferric Chloride ("PCB Etchant", can be found in electronics stores like Radio Shack for ~$10.00)
http://www.radioshack.com/product/index.jsp?productId=210286813) A well ventilated work area with no heat sources nearby
PREPARATION: 1) First, identify the part you want etched. To ensure a uniform depth of etch, first prep the part by sanding it with successive grades from 320 to 1000 grit to remove any surface scratches. #0000 extra fine steel wool, rubbed in a single direction, works well here also. After the part is etched, you'll want to minimize any sanding or polishing operations, so do all of that now.
2) Clean the part with warm water and dish detergent to remove sandpaper grit and slurry. After drying with a microfiber cloth, wipe the part with acetone to completely remove all oils.
MASKING:3) Immediately after cleaning/drying the part, apply a single layer of clear packing tape. Buy the widest tape you can find, or otherwise plan out the orientation so as to minimize the seam lines on your part (the more seams, the more risk of acid seeping into unwanted areas). Your goal is to make the entire part watertight and airtight.
4) The primary tip to consider when applying the tape is to start in one spot and smooth it down, then slowly work around the part while rotating it, smoothing out any air bubbles as you go along. Air bubbles are your enemy!
MARKING:5) Using a fine tip Sharpie, draw your pattern onto the masking tape. If you change your mind, rub off the Sharpie and try again until you have a pattern you're happy with. I like this step because it allows you to see the pattern on your saber itself, before you etch it, which helps visualize the final product in your hands as you go.