Miniature Door

I'm creating a room of miniature furnishings for the home of the mascot of a Boston bookstore that's opening in 2022. We needed a small exterior door that'll be applied at the bottom of the sidelight next to the store's front door that "the mascot uses." It needed to be squirrel-sized, and as sturdy and damage-proof as possible because it'll be exposed to the elements and children, so wood was out of the question. I decided to create the door in poured epoxy using a silicone mold, so that if it ever IS badly damaged, I can pour a new one without having to start from scratch. This build took a lot of steps, but I'm happy with how it turned out.

Mold-making silicone

epoxy

opaque epoxy colorant

scrap wood

brass plate

ferric chloride (be safe with this stuff!)

Ooks picture hanger nail

I wanted the door to echo the front door of the bookstore, and it seemed that including the trim around the door in my build would not only help the illusion, but allow the entire miniature doorway to be thicker and more sturdy.

First, I created the positive "master" for the door, which I'd use to create my flexible silicone mold. I wanted this door to have a real wood grain, so I built the master on a scrap piece of oak, orienting the grain vertically. I applied seven thin strips of oak to form the rails and stiles of the door.

It was important for this to feel as real as possible, so I knew I had to apply tiny mouldings to the inside edges of the panels. But I needed tiny mouldings for that! Using a bench scraper and a number of small files, I created a tiny scratch stock for the mouldings and clamped that to a table. I cut a thin slat of maple, chosen for its long, smooth grain, and repeatedly scraped it past the scratch stock profile until it had been scraped down to the profile I wanted. I cut the mini moulding away from the maple slat on my table saw.

Then I cut 45-degree miters on the moulding pieces and glued them in place. I wasn't overly careful about my miters because I wanted this door to feel the same age as the large door it was patterned after, and that door has seen many decades of wear and coats of paint.

After the trim moulding was in place, I added square trim around the door, leaving a small gap between them for realism. Around that, I applied another, thicker custom-profile trim that I created with another scratch stock I made. When it was all in place, I sanded it gently and gave it a couple of coats of spray polyurethane to help the silicone release from the "master."

I used four pieces of scrap wood and hot glue to create a "dam" around the door / moulding master, and then mixed up a big batch of molding silicone. Pouring slowly, I filled the form to the top of the "dam."

When the silicone had set, I broke away the "dam" pieces, and carefully peeled the silicone off of the master. Peeling it away had that same satisfying feel as when you dig a knife into a fresh jar of peanut butter. The mold was clean and crisp—it had picked up every wood grain detail from the master.

I trimmed away excess bits of silicone (when they say it settles into every tiny void or crack you've left, they're not kidding).

To make the door feel more real, it needed a brass street number plate, and a brass plate for the doorknob and keyhole. I wanted to try etching the brass, and did web research on how to do it using ferric chloride. There are lots of tutorials online—but if you're going to do it, be safe. It's nasty stuff, and you can do some real damage to yourself if you're not extremely cautious.

First, I created a pattern for my plates in Photoshop (with numbers reversed). I printed them out with my laser printer on the glossiest, thin magazine paper I could find. Note: you don't need to worry about finding a blank piece of paper--only the laser toner will transfer to the brass, not the magazine images.

I burnished a piece of ⅛" thick brass to clear the surface of any oils or other things, and give myself the smoothest base for the etching I could. I positioned my pattern face down on the brass, folded it around the stock, and taped it with metallic duct-insulation tape. I'd read that you had to heat the brass well for the transfer to work, so I clamped the bar into a vise, and used a heat gun on the far end of the brass until even the metal under the pattern was hot. Then I used a hot iron on the taped pattern, pressing until I figured any transfer would have had to have happened.

I peeled away as much of the paper as would come off, then cut off the printed part of the brass bar. Under running water, I gently rubbed at the remaining paper until only the toner was stuck to the brass. This was another magic-feeling step—seeing minute details from my pattern shining through the black toner.

I suspended the brass face-down in a small amount of the ferric chloride, checking every fifteen minutes or so until it seemed like the pattern had been etched as much as it was going to be. Another great moment--seeing the plate etched with tiny details clear and intact.

I cut the doorknob and number plates out and filed the sides straight and flat, then polished the top surface with water stones.

This was the part I was most nervous about, because my experience with molding is extremely slight. I also had the challenge of getting colors right—the trim of the real, full-sized doorway is going to be off-white, and the door will be painted a specific paint color from Farrow & Ball, an exclusive paint company.

I decided to pour the off-white door surround first, so I mixed up a batch of epoxy using opaque resin colorants. I worked very slowly, adding tiny amounts of black and brown pigment to the healthy dose of white I'd used, until the color seemed about right. I poured it into the mold and was very happy that it stayed where it was supposed to go and didn't pour into the space for the red door. I don't have photos of this phase because I was too engaged in not messing it up to think about documentation.

After 24 hours, the white epoxy had set well enough for me to pour the door. Getting the color right was crucial, and it took a long time of adding tiny swipes of colorant with a toothpick and mixing them in before I'd matched the official paint color as well as I thought I could. I placed the brass number and doorknob plaques in the mold, and poured carefully around them.

A further 24 hours later, I pulled the silicone mold away from the cured epoxy, and there it was—the finished door. I'd drilled a small hole in the doorknob plaque, and pushed an Ooks picture hanger nail into the hole—voila—a doorknob!

There are some bubbles in the pour that I'll fill with more colored epoxy—note to self next time to slide a toothpick along corners of the silicone mold after pouring, to dislodge these bubbles. I'll give the entire thing a light sanding with my finest-grit sandpaper, and be sure that my brass plates are polished. Before this door is installed, probably in January or February, I'll file its edges smooth and give it a couple of coats of satin polyurethane.