First off I want to thank you for reading this, and hope it can help you in your pursuits. My mycological experience is limited but I have been building mechanical/electrical components for years. This write-up should guide you through building a quality still air box relatively easily and for just $20.
I tinkered with many different concepts, but chose this one because at its base design it can be built relatively cheap with minimal tools, and experience. It also is fully enclosed allowing you to work comfortably in a sterile environment. It utilizes PVC flanges so you can replace your gloves after each work session or as necessary.
This SAB will support inoculation, agar work, G2G, prints/syringes, and cloning. Giving you an affordable foot in the door in clean work.
Note: There are many different approaches to creating a sterile environment. This particular post is about still air boxes. Contaminations can and will happen with every method. This is to decrease the chance of contamination as much as possible.
Items needed to build the base version -
Two 4-inch PVC flanges
Gloves large enough to be folded over the flanges and allow movement in the container!
GE Silicone (Mold resistant)
DUCK heavy duty weatherstrip seal
Start by putting the larger portion of the flange to the container, and trace it with a sharpie. You can use alcohol to clean the marker off the PVC if you are as OCD as me. I used the ribs for the lid to make sure the cut outs were evenly spaced.
One of the reasons I decided to write this was to aide others through my mistakes, and contribute tricks of the trade that I have learned through out my life. This seemingly easy task is where I made several mistakes with my other concepts. "Not all plastics are created equal". Some will crack, tear or split. Not something you want to happen after you have been cutting holes in your box for two hours rendering it useless. Sterilite is a very easy plastic to manipulate, sturdy and cheap!
Use a Dremel! It will save you time, and with practice will give everything you craft a finished appearance. If you have any questions on specifics tips or attachments to use please pm me! I use my Dremel for many different applications.
I started with a course red sanding disk. Start to cut 1/4-1/2 inch away from your outline. Working your way to the other side creating a line. Start again from the outside working your straight to the other side creating an X. This now allows you to manipulate the plastic without ruining it.
Continuing to use the same small red sanding disc cut around the circle in the 4 tabs you created. You can push or pull on the "tab" to get a good cut. Use gloves because to be precise you need to be close.
You have created your flange hole! From here change attachments to the orange grinding stone. You need to smooth out the cut, and the grinding stone slowly cuts, and melts the plastic giving you a great surface for your silicone to seal too.
*I pressed the flange into the container* As you slowly enlarge your hole with the grinder you need to try and work your flange through the hole. You can eventually get it to the point where you will feel resistance but it will press in! Giving you a tight fit even before you seal it with silicone!
Rinse, lather, and repeat for the other flange
Next you need to make sure that no air is escaping past your flanges. I used a GE Silicone that is mold resistant. You can use whatever you are comfortable with. I chose the silicone for a specific reason.
Start by pulling your flanges halfway out of the holes you just created. Place a good bead of silicone around the lip of the PVC that will be pressed into the container. Now slowly press them into the holes until the flange is seated against the plastic container. I clamped it down overnight and added some weight.
Next you need to seal the flange on the inside of the container. Start again by placing a large bead all the way around the flange. Here you can use a trick to ensure the seal has no air holes, and looks professional. Alcohol restricts the silicone sticking to your skin. Spray your finger/nitrile glove with alcohol, and run it around the bead ensuring you have coverage from the container up to and around the flange. Now let it cure
After the flanges have cured take your heavy duty weather seal and apply it around the lip of the plastic container where the lid seats. Cut a 1/4 in notch around the corners of the container to allow the weather seal to bend. Here you can see it in action with the lid on.
* I will upload a better picture of the seal installation soon*
Next use the Dremel to cut guides around the flange to secure your gloves. I used the orange grinding attachment to create a 1/4 inch guide in the four beveled edges you see around the flange. This will give the zip-tie securing your glove to the flange a flush all around seal.
*I will upload a better picture of the guides soon
Edited by Rabbittt, 25 April 2017 - 03:30 PM.