By John Lester - images & text © 2007
If you build models long enough, you will eventually run across photoetched or "PE" parts. These are flat metal (usually brass, but sometimes stainless steel or copper are used) pieces that are used to provide detail on models that can't easily be replicated in plastic or resin. It's possible to make some very intricate, or very small (or both) detail with photoetched metal, which is why modeler's like the stuff.
Much like the familiar plastic model kits, PE parts come attached to a "parts tree". Usually you will buy a sheet of metal that has many parts attached by small stubs to the carrier sheet. These parts are made by etching away excess metal until only the desired shapes remain. PE parts can be used as they are found on their sheet, or bent, folded and/or laminated to make more complex shapes.
PE is not difficult - in theory - to use, but it can be expensive, so you'll want to know what you're getting into before you start spending that hard-earned hobby cash.
The most basic tools you'll need for working with PE are a pair of tweezers and a hobby knife. A metal file is a good idea. If you need to bend the parts, you will need (at minimum) a steel straightedge and a razor blade. More on this in a bit.
As with anything else, more specialized tools can help you get better results with less difficulty. You may use a hobby knife to detach parts from the carrier, but you'll wear the blades out quickly. I prefer small scissors, like those made by Tamiya; they're just as easy to use and they'll last forever (or as close to forever as I'll be building, anyway). Tamiya also makes a set of pliers with a long smooth bill that work well for simple bends on small parts. I mention these because they are what I use. There are many different brands of similar tools - check out MicroMark, Model Expo or Harbor Freight online, or your local craft and hardware stores, for similar products.
If you are doing a lot of work with PE, you may want to invest in high-end folding tools like Mission Models' "Etchmate" or The Small Shop's "Hold and Fold". These have different shaped clamps and cutouts for bending all sorts of shapes. They can be pricey - my Etchmate cost $60 - but in my experience, money invested in a good tool is never wasted unless you don't use the thing.
There is not a lot that needs to be done to PE to prepare it for use. You'll want to make sure the metal is clean and free from any remaining etching chemicals, oxidation, skin oils, toilet water (don't ask), etc. Because the PE parts are usually small and connected to the fret with tiny "sprues", you don't want to scrub them too hard. I have found the quickest and safest way to clean a PE sheet is to immerse it in vinegar for a few minutes. Vinegar is a very mild acid; leave the metal in for no more than 10 minutes (less if it is soft brass or copper) and then rinse the sheet with water.
If you will need to bend the metal, or if it is very stiff, you may want to anneal it. 'Annealing' is a process where a metal is heated then allowed to cool slowly, changing its strength and hardness along the way. For us, this means holding the PE sheet over a flame (a candle works, but the burner on the stove works better) until it is very hot. Slowly wave the sheet over the flame so that the whole thing heats as evenly as possible. Nothing irritates the wife or significant other like burning down the house, so use some common sense if you do this; don't be an idiot and set the red-hot metal on a stack of newspapers to cool. I use a pair of surgical forceps (they look like a pair of pliers with the handles of a scissors, with a locking mechanism) to hold the PE sheet while I heat it, then set the whole thing outside on a table to cool.
The most common method of attaching PE parts to any other material is superglue. The strongest bonds will be made by soldering the parts together. However, soldering only works when you are joining metal to metal (there's nothing quite like a soldering iron for melting plastic and setting wood or paper ablaze, after all). Outside of some of the complicated trusses on satellite and space probe models, I can't think of when you would need to solder anything, so I won't go any further into the subject.
Superglue (cyanocrylate adhesive or "CA") is the weapon of choice when affixing PE to itself or to any other material. On the plus side, CA sticks to most anything and does not require a lot of surface area to make the bond; on the minus side, it doesn't have a lot of shear strength (force applied parallel to the glued surfaces will tend to break the glue's bond). Depending on the application, you may also use epoxy glues (if the PE will be bearing any kind of load), white glue or even Future or paint. I will very often attach brass instrument panels to printed acetate backings by painting Future (a brand of clear acrylic floor covering - it's essentially clear, water-soluable paint) on the acetate and setting the brass piece over that. As long as there is no force applied across the two pieces, the adhesion provided by the Future/paint is sufficient ("what Future has brought together, let no man rend asunder….")
Putting It All Together
So …. You have your PE sheet, a hobby knife, superglue and the desire to use them. What next?
The first step is to trim the PE part from the fret. You will want to cut the attachments as close to the part as possible. If you are using a hobby knife, lay the sheet on a hard surface - the metal will deform as you push a blade through it, if you provide the opportunity to do so. Yes, the kitchen counter works as a backing for the process; save yourself the angst when your wife/SO catches you in the act and get a piece of tempered glass to use instead. You can find this at the local discount retailer (Wal-Mart, et al) marketed as a cutting board - how apropos. Of course if you use scissors, you won't need a backing. In either case it really helps to stick the part you're freeing from its metal bondage to a piece of tape just in case it goes flying and dives for the carpet. It's a LOT easier to find the tape than it is to find the tiny piece lost on the floor. Don't ask how I know that either.
If you are really good, or get lucky, there won't be any excess metal where you cut the piece off. Don't count on that happening. A flat needle file is all you need to trim any excess down.
If you can use the piece without shaping it the next step is to glue it in position. You will not need a lot of glue. If you use too much, it tends to ooze around the edges and ruin the detail you were using the PE to make in the first place. If I am placing the PE against a flat surface, I use a toothpick to put a dot (or dots) of superglue where needed. If I am placing something, like a railing, where very small attachment points are used, I grab the PE part with tweezers and dip the attachment point in the glue before placing it. In this case, I'll pour a puddle of glue on an old business card and dip the PE in that.
For a complicated fold, like a railing around a ship's deck, I'll test-fit the piece repeatedly. I place it in position, mark where a fold or bend needs to happen with a fine-tipped marker, make the fold, place in position again and repeat as necessary.
For the simplest folds, lay the metal piece on your hard surface (glass or kitchen counter depends on if the wife is awake). Place the metal straightedge (or the edge of your pliers) along the edge that needs to be folded. On almost all sheets, this will be indicated by a recessed line. Place the edge of the razor blade under the "free" metal and bend a bit past the angle you need - the metal will spring back.
Metal can be painted with anything the rest of the model is being painted with. I like to use a primer just to insure that all materials that comprise the model look the same before I start with the color coats.
Using PE is not difficult, and enables you to add an exponential level of detail to your models. Whether you use the whole sheet or just selected parts, you owe it to yourself to give the stuff a try!
This page copyright © 2007 Starship Modeler. First posted on 31 January 2007.