This Instructable will be part of a series that will start by looking into creating minimal surface’s using sand and the process to do so, from creating a container to do the tests in to how the surface responds to different parameters, and how to solidify a layer of the geometry.
This is the creation of the first box that I created for the sand solidification process. I learned many things from the first cast on ways to improve on the box and will be creating a v2 Instructable for it soon.
What I used:
There were a few issues that appeared during the experiments that I have come up with a way to fix the issues that I had with the first version.
Issue 1: Friction
This issue was caused by the friction between the sand and the two surfaces making it almost impossible to pull out in one move, which led to poor results during the experiments. This was in part because of the tolerance between the two surfaces being too tight.
Solution 1.1: There are multiple ways I can see fixing this problem, the first would be to increase the spacing between the two boards, but this may cause some issues still with friction still while pulling back and may have negative effects on the casting.
Solution 1.2 (Next Build): The second way, which I will be exploring soon will be a system that allows the bottom tray to drop. This means there will be no friction between the two surfaces and it will allow for all the voids in the top surface to open at once, hopefully allowing for more consistent results.
Issue 2: Surface removal
The second issue that I ran into was removing the solidified sand from the box. This occurred only with the hairspray models (see Sand Solidification https://www.instructables.com/id/Solidifying-Sand), which is the method that I currently prefer, and due to its bond and time for setting.
Solution 2.1: Coating and Waxing
The first solution I explored was Clear Coating and Waxing the wood with a Paste Wax. You could just Wax the wood but I didn’t have any at the time of need. When Waxing the wood you need to apply it liberally to the surface using a paint brush and after letting it set for a little while buff it with a cloth. You would then repeat a number of times until you have a good base built up and allow it to dry. This method is pretty time consuming but did seam to help greatly with the sand not binding to the surfaces.
Solution 2.2(Next build): Acrylic Box and Surface
The second solution includes using an acrylic surface to help keep the binding to happen. I haven’t done a full test with this yet but have seen a similar method done with acrylic. This solution will be incorporated in my next build (v2) and will include Solution 1.2 as well.
Step 1: Box Creation – Dimensions
Decide on the dimensions you want your box to be, I choose a 2-foot long by 1-foot wide by 1-foot tall as my interior dimension. This allowed me to create 2-foot by 1-foot surfaces that would fit snuggly into the box. These dimensions are up to you but by using a rectangular shape it allows you to create patterns that “run” over a length.
Step 2: Box Creation – Cutting Out
For my material I used ¾ in plywood that is available at Home Depot in 2 ft x 4 ft sheets as well as some scrap of the same cut that I found around the shop. After marking all my cuts I cut out my side-walls (2 X 2’-1 ½” x 1ft, 2 X 1’ x 1’)(the extra material will be used to make sure the opening is exact) as well as my base, which was 2’-1 ½” x 1’ 1 ½”. I also cut out a rail system, which consists of 2 X 1” x 2’, 1 X 1” x 10”, 2 X 2” x 2’ and 1 X 8” x 2” rails. I also cut out a tray which is 10” x 24”. The final cut was to make an opening for the tray to be removed, I did this at 6” to the top of the tray and ¾” down.
Step 3: Box Creation – Assembly
Assembling the box I decided to leave two walls removable to help with the removal of the casts as well as being able to photograph them easily. I butted a 1’x1’ wall piece against the larger wall, wood gluing and using a nail gun to make sure they are secured. I then attached them to the base using the same method. Next, I predrilled holes along the remainder of the base edges to set up the remaining walls, then putting the walls in place and using the holes drilled in the base I pre drilled into the walls and secured them onto the base. I then predrilled and screwed in the walls to each other ensuring a tight fit.
After I made sure the walls fit in place I removed the two side-walls and attached the rails to all the interiors of the walls, making sure that the system is set up to allow you to remove the tray.
Step 4: Box Creation - Final Fit Together
I re-attached the walls together and slid in a 2’ x 1’ sheet I had cutout to make sure the fit was tight, and that the tray can easily be slid in and out of the box.