There's been a lot of discussion about inexpensive alternatives to buying two way mirrors. After seeing Larry Lund's page and instructions for his Bottomless Pit, I decided to build one. After finding out that a 2' by 2' two way mirror would cost $55, I wanted to find an effective and less costly alternative. From the posts I had read I saw that some list members had built pits using mirror paint or film on Plexiglas to create their own versions of the Bottomless Pit. Spookdawg had done this and had pictures of the Pit online. After visiting Spookdawg's page, I decided to give it a try. So with many thanks to Larry Lund and Spookdawg for their examples and their invaluable advice, here are pictures of my version of Larry Lund's Bottomless Pit. If you have any questions email me at trishanc@hotmail.com.
Material list: (This is the same list as found on Larry Lund's page with some exceptions. I used 1/2" thick foam and instead of a 2 way mirror I used 1/4" Plexiglas and Privacy Mirror Film.
2 10' 2" x 4" (these must be very straight and will be used for the mirror supports)
1 4' x 8' sheet of 3/8 CDX plywood ( for the walls )
1 2' x 2' mirror (1/8" plate mirror)
1 2' x 2' 2-way mirror*
Alternately:*
2' by 2' 1/4" piece of PlexiGlas
Roll of Gila Privacy Mirror Film (This was also used by Spookdawg)
Bottle Gila Film aid which is like a glass cleaner for the Gila film.
Squeegee
2 2' x 8' x 1/2" foam insulating panels (to make fake stones, I used the blue kind from Lowes)
1" X 2" pine for brackets
Screws
1 100W light bulb and socket.
2 tubes of Liquid Nails construction adhesive.
1 Quart latex paint (Paint with solvents can damage the foam)
Tools Required:
Router or table saw to cut the grooves for the mirrors
Screwdriver
Drill and bits
Paint brushes
Band saw or saber saw
A dust mask (Important!)
I have finally completed the exterior of my pit and as a result, I've changed some text and some steps around. The original issue was how well would this pit work without a 2 way mirror and I have plenty of pictures and a separate section to answer that.
Here is the pit completed. I added a lot of touch up to it to make it look like something that's actually been outside for a while. I used a lot of vines and moss on the outside.
Here's a picture of the unit assembled but still waiting for the exterior stones to be attached. The L brackets were needed to pull the sides in straight and are hidden once the faux rocks are applied. Each corner has 3 brackets.
This is the 3/8" plywood for the sides and 1/2" extruded foam for what will be the stones. I had intended to use 3/8" foam like Larry's instructions called for but Lowes only had 1/2" so I made do with 2 sheets of that.
The one sheet of plywood was sufficient for all four sides of the pit.
Here is one of several side by side comparisons of a regular mirror and the Plexiglas with the privacy film. I included this to show that there is a definite tint difference between the two. Since they aren't going to be displayed side by side, it really doesn't matter too much. The inside of the pit will appear slightly darker than it would if a regular 2 way mirror were used but it is totally functional.
I am going to quickly show the different steps in the process. On this page I am focusing on building the top and bottom frames which will house the mirror on the bottom and the Plexiglas on the top.
Before routing out the grooves, make sure you are making the proper sized cut. The mirror will be 1/8" but the Plexiglas will be 1/4". Also as Larry mentions, make sure you are routing from the same edge so that the grooves all line up properly.
After routing the grooves for the mirrors, as per Larry Lund's instructions, I painted a base coat of gray. I followed that up by sponging some black paint and some white paint. I created texture by adding some dry cement mix to the paint three different paints; the gray, the white and the black.
This is the assembled bottom unit with the mirror. The plate mirror is on the other side. It is supported by the plywood as well as the brace running through the middle. Again these are the same steps as found on Larry Lund's site.
Testing the reflection using the Plexiglas in an outdoor shot.
Now it's time to build the pit itself. The light has already been installed and the mirror is easily seen but that will change once the stones are attached .
As you can see the pit already looks bottomless, sort of. Once the stone, moss and vines are added, it will look much more realistic.
Here I am cutting the stones with a saber saw. As per Larry's instructions, I numbered the stones as I cut them to make sure they fit properly on the inside walls.
The rough cut stones. If you look carefully at the larger image, you can see the numbers on the individual pieces as well as the outline for the remaining stones that will be cut from this piece.
Once these stones are sanded down and smoothed they will be painted.
Here I'm sanding the edges of the foam smooth and rounding the corners as well. This combination belt and disk sander is a terrific time saver! When I sanded the stones for the interior of the pit, I didn't wear a protective mask and I actually felt discomfort breathing. Now I wear a mask to keep the foam particles out of my lungs. They are cheap and they work. If you are doing anything that results in small particles getting thrown into the air, make sure you wear a dust mask.
This is just laying out the stones to see how they will fit on the wood. I am leaving enough space between the stones to add vines or moss or whatever.
Here I am doing the outside stones but it works the same way when applying the stones to the inside walls.
Here the stones have been painted a flat gray for the base color. I use three plates; one for the gray paint, one for the black paint and one for the white paint. I add dry cement mix to all three paints.
After coating the stones with the gray base I sponge paint black and white in order to give the stones a more natural look. The dry cement mix adds a natural texture to the stones.
With most of the prop built, now it's time to attach the stones. If the stones were cut and properly laid out, this is not difficult. Unless you hinge one of the walls, the toughest part is climbing in to place the stones.
Here's a picture looking down into the pit with the stone in place. That thing in the middle that looks like an oncoming train is just the camera. It's not as easy to see in the picture but there is some moss and vines that are "growing" along the walls.
Here's a picture looking down into the pit with a ladder added to the inside.
Important Safety Tip: This is why a ladder is a good idea for a bottomless pit. If you *do* fall in, you can always climb back out.
The pit taken apart into its three components. You can see the ladder on the back wall of the pit. The yardstick shows that this section is 3' tall.
A slightly overexposed picture showing the inside of the main part of the pit with the ladder and without the mirrors.
Original author: WormyT (Trisha Morse)
Original URL: http://halloweenpropmaster.com/Wormyt/Bottomless_Pit/pit1.html