|Partial Pressure Box||-|
|By Nan (Nanook) on Friday, October 26, 2001 - 04:16 am:|
Making a Glove Box
This is the easiest, effective transfer box I know of. Even if you have to buy everything the cost should be under $35. There are several easy enhancements to this design, but this is a good basic box for beginners and takes about 20 to 30 minutes to throw together.
Plastic storage box approx. 16" x 24" x 12" deep (Walmart),
Plexiglas cover for box (Home depot),
Computer fan 120V (your old 286 or Radio Shack or Here's a link to "the computer fan outlet store" At the last check, they had some appropriate case fans for $4. One should verify that they are 120V AC before purchasing.)
Screws to fasten the fan to the box (about 1/2" longer than the fan is thick),
A GOOD disposable dust mask or a HEPA replacement filter. (The HEPA filter is $15 minimum)
2 Plastic bags (small lightweight trash bags work well)
If your fan needs a power cord, buy a 99 cent extension cord and cut the end off. It's far cheaper than buying a cord packaged as such. Wire nuts are also very desirable to attach the cord to the wires from the fan. No self respecting DIYer throws away a device with the power cord still attached ;-)
In these photos you can see the dust mask on the outside, the fan on the inside, the "gloves" wrapped together and held with a clothes pin, and this box also features a hinged lid. The small section of plexiglas is taped in place and the door part is attached to the small section with a tape hinge.
GOOD scissors or tin snips
appropriate screw driver
a hair dryer
That's all you need. Using a HEPA cartridge is better than a dust mask, but the dust mask setup works fine if you're on a tight budget.
Here you can see the fan mounted in the box. If you look hard, you can see through the translucent box, and see the dust mask taped over the intake hole on the outside.
1. Cut holes in the side of the box for your arms. Heating the box with a hair dryer makes the cutting much easier.
2. Drill pilot holes to mount the fan to the inside of the box. A hot ice pick works well as a drill.
3. Cut out a hole inside the four screw holes for the fan to draw through. It should be at least 2" in diameter.
4. Mount the fan inside the box, blowing into the box. Seal with duct tape. Put the dust mask on the outside of the box over the draw hole and seal to the box with duct tape.
5. Stick your hand into the bottom corner of a trash bag. Now stick your arm thru' the arm hole as far into the glove box as you are likely to need to reach. Trim off the excess bag and use duct tape to attach the "glove" to the outside of the box around the arm hole. Repeat for the other arm hole.
To keep the gloves from billowing out like balloons when you turn on the fan, you can sort of wrap them around each other and hold with a clothes pin. You'll discover one of the nicer aspects to the design is that with the fan running, the pressure presses the "glove" against one's hands. This keeps the excess plastic from being a hassle. (This type of "cheapo" glove doesn't work if you suck air out of the box instead of the positive pressure design, but the best reason to use positive pressure in the glovebox is that leaks in the system are harmless. Filtered air pours out of them instead of unfiltered air being sucked in through them.)
To use: Wipe down (or spray) the inside of the box and the under side of the plexiglas top with Lysol. Spray one glove heavily, then rub your hands (in the gloves) together to clean and sterilize the gloves. Place your materials in the box, lay the top in place, and turn on the fan. Allow it to run for a while (15 minutes is probably overkill). The positive pressure in the box means that filtered air is pouring out of every opening. The dust mask filter can be sprayed with Lysol as an extra precaution.
CAUTION: Using a knife to try to cut the plastic is very dangerous. The polypropylene that these boxes are made of is very tough and will crack without warning if you're using a lot of pressure with a knife. I ruined the first box and could have lost fingers the first time I built one of these. I tried to use a razor knife with a new blade and it did not work. Use a hair dryer and good, heavy duty scissors or tin snips. If you are not experienced with taking power supplies apart and general tinkering, please get someone who is to help with the wiring up of the fan.
[Note from Nan... If you flip the box on it's side and cut the holes in the bottom you do not need a custom plexi lid]
Main Page : The Glove Box : Cloning : The Substrate : Casing/Fruiting : Spore Collection Blender Usage : Tips
Be careful with flammable disinfectants and flame in a glovebox, they can (and do) explode!
Sanitizer fumes are also highly toxic to mycelia Ventilated boxes are much less dangerous.