Cutting Out Etched Brass

Etched brass features in several of my model kits and has been used as a way to model tiny detailed parts for many years.  But how do you cut the parts out?

A sheet of etched parts, or fret, normally consists of a sheet of metal with all the parts attached by a half-etched tag.  This means the area around the part has been fully etched away except for a small tag which is only half as thick as the rest of the sheet.  Below is the etched brass ‘Additions’ sheet for my N scale Alco C-855B locomotive.  As well as the larger handrail section there are also several other parts, such as ladders and grab irons, which are much smaller and more delicate.

The half-etched tag serves two purposes; it marks where the part finishes and needs to be cut off, and it makes the actual cutting of it easier, as the material is only half as thick.

With thinner sheets and softer metal such as brass, the tags can be cut with a sharp knife.  I use what is commonly called a Stanley Knife as the blade is strong but sharp.

However, there’s a risk of damaging or bending the parts as the pressure needed to cut the metal is more than the force needed to bend the parts, particularly with tiny parts. Stainless steel etches are harder to cut than brass etches, because the material is harder. This is more noticeable especially on a metal or hard surface, and you may struggle to cut the etch at all. If you cut either material etch on a cutting mat the blade will drag the part down as you exert the force needed to cut through, resulting in bending the part.  The stainless etch below has some very small parts, the squares on the cutting mat are 0.5″ (12.5mm).

This stainless steel etch is from a kit by Keystone Details and zooming in you can see some of the tiny details.  Under the ladder is an electrical box that needs to be cut out and folded to make the box.

If I attempted to cut any of these parts out with a knife they would certainly get damaged.  So I use a special pair of scissors designed for doing this job.  Mine are made by Tamiya specifically for photo-etched parts.

The tips are small and curved which allows them to easily fit in the gap between the part and the fret so you can cut the tab releasing the part.

It’s not always possible to cut the tab off exactly where the part starts, so this little burr will need to be filed off.  Be sure to hold the part firmly between flat surfaces otherwise the filing action could also bend it.

Sometimes the fret is made from fairly thick metal.  The HO DT6-6-2000 etched brass Additions are made from 0.5mm thick brass compared to the N scale ones at only 0.25mm.  This was done to give the desired size of the handrail on the HO model, but it does mean the tabs are much harder to cut.

I use a much larger pair of scissors here with a strengthened set of blades for thicker metal.  These are ideal for removing sections of the fret to enable better access to the parts.

So I use a mixture of the Stanley Knife and scissors, depending on the part I’m removing.  It’s best to test cut a section of the fret that you don’t need, to gauge which tool is best.

This isn’t the only method for cutting parts from etched frets, there are also other tools for cutting photo-etch, however, I haven’t tried them yet because what I have works well for me. As modelers, we’re inventive in our use of tools and materials, but it’s helpful when we find a tool designed to get the job done, ie cut out parts that aren’t bent or burred.