Small ventilated lampwork bench
Small ventilated lampwork bench Written by Sheila Summers These instructions are for a bench exactly like mine, which is shown below.
Tools
Drill Electric screwdriver Saw—you can use a hand saw, but your cuts won’t be very straight and it’ll be a lot of work. A power saw would be better. I used a miter saw for cutting the boards and had Lowes cut the wood for my work surface. Tin snips for cutting the sheet metal. Dremel with a quick cut bit, or something you can use to cut a round hole in the acrylic sheet if you plan to attach the fan to the side. Tape measure
Calculate the size fan you need The most commonly-used fan size calculation is 125 CFM for each square foot of area in the hood opening. Here’s the formula: (width x height) x 125 = CFM My hood has an opening that is a little less than 2’ x 3’, so for me the formula looks like this: (2’ x 3’) x 125 = 625 If you make your bench exactly as I describe in these instructions, you’ll need a fan that is rated at 625 CFM or higher. Note: Some people suggest a smaller fan for a fully-enclosed, or Barley Box style, hood. Although this workstation is fully enclosed, I erred on the side of caution and got the larger of the two recommendations. I chose the 675 CFM CAN inline fan from Maryland Hydroponics, which is available at http://www.mdhydro.com/ventilation.html. It took about a week for the fan to arrive, and their service is reported as excellent. You could also use a squirrel cage or Vortex fan. They recommended the CAN inline fan because it is the quietest they sell. It’s still fairly loud, so keep that in mind when you choose its location. Do not use a duct booster fan, like those available at Lowes or Home Depot. I can’t stress that strongly enough. They don’t work. My original hood had this type of fan. When I tested it, the smoke drifted up into the hood and was eventually pulled out by the fan. The 8” duct booster fan may be rated at 600 or more CFM, but that is only if it is installed in a heating system. When it is installed by itself, it is only rated at about 200 CFM, which is not strong enough to vent the fumes. Choose a higher CFM fan if your ducts need to go a long distance or if makes turns. The formulas to calculate the necessary CFM are on the forums. Mine goes less than 3’ to an opening in the wall that I made for my old hood. I went a little higher than 600 CFM because the duct makes a 90° turn. It is very important to have the correct CFM, and stronger is not always better. You’ll have to do some research to figure out the best fan for your situation.
Supplies
Ducting to attach your fan. I don’t know what you’ll need, so you’ll have to figure this out yourself. Do not use flexible ducting! I used a 8” 90° elbow and a stove pipe duct, because my ducting is fairly short. One 36” wide, 54” tall, 14” deep heavy-duty shelving unit. I used stainless steel wire type shelves that I got from Lowes.
Important: The dimensions of all wood, acrylic sheet, and aluminum are based on the shelving unit I bought at Lowes. You will need to adjust these dimensions based on the unit you buy. You should buy the shelf and complete step 1 of the assembly instructions (below) before you buy and cut the remaining supplies.
One 33” x 24” piece of plywood or other rigid wood that is suitable to use as a work surface. It must be strong enough to support a little weight, because it extends beyond the front edge of the shelf. Some hardware stores will cut this for you; just make sure it’s not wider than 33”, or it won’t fit. It’s ok if it is a bit narrower. Lowes cut mine for me and the size was close enough.
Sheet metal: I used sheets of aluminum, because it’s inexpensive and easy to cut. One 33” x 24” piece to cover the work surface One 35” x 24” piece for the back baffle One 33” x 21½” piece for the top of the hood Boards: One 33” long piece of 1x6 for the front of the hood Two 20” long pieces of 1x6 for the sides of the hood One 31½” long piece of 1x2 for the back of the hood Two 11” long pieces of 1x2 to support the work surface Two 21” x 22” pieces of acrylic sheet (like Plexiglas) I got the thinnest sheet they had at Lowes, and had them cut it for me. Four 90° angle brackets, about 2” x ½” Wood screws: A small box of ⅝” long screws Four 1¼” long screws Eight 1¾” long screws Four 1¼” hose clamps. You will use these to secure the hood top to the shelf. One fluorescent light fixture that is 33” long or shorter. I used a 20” long fixture with one bulb.
Assembly instructions Note: Always drill pilot holes in the wood before you attach screws. I don’t tell you to do it in every step that requires screws. If you don’t, your wood will split. 1. Assemble the shelving unit: a. Attach the bottom shelf according to the instructions that came with the shelf. Tap lightly with a hammer to slide the shelf down onto the spacers. b. Position the second shelf so your knees won’t bump it when you sit in your chair. c. Don’t attach the third or fourth shelves yet. 2. Assemble the work surface shelf: a. Place the wood for your work surface face down. b. Put the shelf face down on the work surface. Ideally, you want a ⅛” gap on either side of the work surface. The acrylic sheets that make the sides of your hood will fit into these spaces. If you don’t have a gap and can’t cut the work surface down, you will need to attach the acrylic sheets to the sides of the shelving unit. c. Put the two 11” pieces of 1x2 board on either side of the shelf. d. Drill four evenly-spaced pilot holes through each of the 1x2 boards and into the work surface. Don’t worry if you drill through the work surface, because it will be covered with sheet metal. e. Screw the 1¾” long screws in the pilot holes. You could bolt the work surface to the shelf instead, if you prefer. I didn’t want bolts on my work surface, and I don’t have the tools or skill to counter-sink the bolts. If you don’t have the means to cut a piece of plywood for the work surface, you can use six 24” long 2x6 boards instead. Just attach each board to the shelf. It’ll be covered by sheet metal when you’re done.
3. Position the work surface shelf: a. Position the shelf about 30” from the ground. b. Get your chair and check the height before you tap the shelf down onto the spacers. 4. Build the top of the hood: a. Cut a half-circle that is the same diameter as your duct in one of the 1x6 boards. I attached my duct to the side, so I cut the half-circle near the back of one of the 20” long boards. b. Use the angle brackets to attach the two 20” long pieces of 1x6 on either end of the 33” long piece of 1x6. The 33” long piece is the front of your hood. c. Use the 1¼” long screws to attach the 31½” long piece of 1x2 between the 20” long 1x6s. This is the support for the back of the hood. d. Attach the fluorescent light to the inside of the front of the hood. e. Attach the 33” x 21½” piece of sheet metal to the top of the hood with ⅝” long wood screws. I placed them about every 5”. f. Put the hood on the work surface and mark the spots where you want to attach the hose clamps. These will secure your hood to the shelving unit. g. Open the hose clamps and straighten them out. h. Drill pilot holes through the hose clamps and into the sides of the hood. i. Screw the hose clamps in place with ⅝” long wood screws. 5. Finish the hood: a. Tighten the hose clamps so their diameter is about 1½”. b. Slide the hood onto the shelving unit so each hose clamp is on a support. Put it on the work surface for now. c. Put the top shelf on in the highest position. d. Slide the hood up as far as you can so it is directly under the top shelf. e. Tighten the hose clamps. You want them as tight as you can get them, because they are holding your hood in place. f. Slide the acrylic sheets on each side of the hood. If you have a small gap between the work surface and the side of the shelf, slide the sheets into this gap to keep them in place. g. Screw the acrylic sheets in place. h. Put the 35” x 24” piece of sheet metal on the back and screw it in place. i. (Optional) Seal all the seams inside your hood using foil tape. 6. Attach the fan: a. Make a hole in the side or back for your fan. The hole should about ½” from the top of the hood. Mine goes in the side, through the wood and acrylic. I don’t have any recommendations on how to cut the sheet metal, if you go through the back. Tin snips would probably work well. b. Tape the duct to the hole with foil tape. You may need to replace the tape periodically, but I can’t imagine it would have to be done more than once a year or so.
Tools
Drill Electric screwdriver Saw—you can use a hand saw, but your cuts won’t be very straight and it’ll be a lot of work. A power saw would be better. I used a miter saw for cutting the boards and had Lowes cut the wood for my work surface. Tin snips for cutting the sheet metal. Dremel with a quick cut bit, or something you can use to cut a round hole in the acrylic sheet if you plan to attach the fan to the side. Tape measure
Calculate the size fan you need The most commonly-used fan size calculation is 125 CFM for each square foot of area in the hood opening. Here’s the formula: (width x height) x 125 = CFM My hood has an opening that is a little less than 2’ x 3’, so for me the formula looks like this: (2’ x 3’) x 125 = 625 If you make your bench exactly as I describe in these instructions, you’ll need a fan that is rated at 625 CFM or higher. Note: Some people suggest a smaller fan for a fully-enclosed, or Barley Box style, hood. Although this workstation is fully enclosed, I erred on the side of caution and got the larger of the two recommendations. I chose the 675 CFM CAN inline fan from Maryland Hydroponics, which is available at http://www.mdhydro.com/ventilation.html. It took about a week for the fan to arrive, and their service is reported as excellent. You could also use a squirrel cage or Vortex fan. They recommended the CAN inline fan because it is the quietest they sell. It’s still fairly loud, so keep that in mind when you choose its location. Do not use a duct booster fan, like those available at Lowes or Home Depot. I can’t stress that strongly enough. They don’t work. My original hood had this type of fan. When I tested it, the smoke drifted up into the hood and was eventually pulled out by the fan. The 8” duct booster fan may be rated at 600 or more CFM, but that is only if it is installed in a heating system. When it is installed by itself, it is only rated at about 200 CFM, which is not strong enough to vent the fumes. Choose a higher CFM fan if your ducts need to go a long distance or if makes turns. The formulas to calculate the necessary CFM are on the forums. Mine goes less than 3’ to an opening in the wall that I made for my old hood. I went a little higher than 600 CFM because the duct makes a 90° turn. It is very important to have the correct CFM, and stronger is not always better. You’ll have to do some research to figure out the best fan for your situation.
Supplies
Ducting to attach your fan. I don’t know what you’ll need, so you’ll have to figure this out yourself. Do not use flexible ducting! I used a 8” 90° elbow and a stove pipe duct, because my ducting is fairly short. One 36” wide, 54” tall, 14” deep heavy-duty shelving unit. I used stainless steel wire type shelves that I got from Lowes.
Important: The dimensions of all wood, acrylic sheet, and aluminum are based on the shelving unit I bought at Lowes. You will need to adjust these dimensions based on the unit you buy. You should buy the shelf and complete step 1 of the assembly instructions (below) before you buy and cut the remaining supplies.
One 33” x 24” piece of plywood or other rigid wood that is suitable to use as a work surface. It must be strong enough to support a little weight, because it extends beyond the front edge of the shelf. Some hardware stores will cut this for you; just make sure it’s not wider than 33”, or it won’t fit. It’s ok if it is a bit narrower. Lowes cut mine for me and the size was close enough.
Sheet metal: I used sheets of aluminum, because it’s inexpensive and easy to cut. One 33” x 24” piece to cover the work surface One 35” x 24” piece for the back baffle One 33” x 21½” piece for the top of the hood Boards: One 33” long piece of 1x6 for the front of the hood Two 20” long pieces of 1x6 for the sides of the hood One 31½” long piece of 1x2 for the back of the hood Two 11” long pieces of 1x2 to support the work surface Two 21” x 22” pieces of acrylic sheet (like Plexiglas) I got the thinnest sheet they had at Lowes, and had them cut it for me. Four 90° angle brackets, about 2” x ½” Wood screws: A small box of ⅝” long screws Four 1¼” long screws Eight 1¾” long screws Four 1¼” hose clamps. You will use these to secure the hood top to the shelf. One fluorescent light fixture that is 33” long or shorter. I used a 20” long fixture with one bulb.
Assembly instructions Note: Always drill pilot holes in the wood before you attach screws. I don’t tell you to do it in every step that requires screws. If you don’t, your wood will split. 1. Assemble the shelving unit: a. Attach the bottom shelf according to the instructions that came with the shelf. Tap lightly with a hammer to slide the shelf down onto the spacers. b. Position the second shelf so your knees won’t bump it when you sit in your chair. c. Don’t attach the third or fourth shelves yet. 2. Assemble the work surface shelf: a. Place the wood for your work surface face down. b. Put the shelf face down on the work surface. Ideally, you want a ⅛” gap on either side of the work surface. The acrylic sheets that make the sides of your hood will fit into these spaces. If you don’t have a gap and can’t cut the work surface down, you will need to attach the acrylic sheets to the sides of the shelving unit. c. Put the two 11” pieces of 1x2 board on either side of the shelf. d. Drill four evenly-spaced pilot holes through each of the 1x2 boards and into the work surface. Don’t worry if you drill through the work surface, because it will be covered with sheet metal. e. Screw the 1¾” long screws in the pilot holes. You could bolt the work surface to the shelf instead, if you prefer. I didn’t want bolts on my work surface, and I don’t have the tools or skill to counter-sink the bolts. If you don’t have the means to cut a piece of plywood for the work surface, you can use six 24” long 2x6 boards instead. Just attach each board to the shelf. It’ll be covered by sheet metal when you’re done.
3. Position the work surface shelf: a. Position the shelf about 30” from the ground. b. Get your chair and check the height before you tap the shelf down onto the spacers. 4. Build the top of the hood: a. Cut a half-circle that is the same diameter as your duct in one of the 1x6 boards. I attached my duct to the side, so I cut the half-circle near the back of one of the 20” long boards. b. Use the angle brackets to attach the two 20” long pieces of 1x6 on either end of the 33” long piece of 1x6. The 33” long piece is the front of your hood. c. Use the 1¼” long screws to attach the 31½” long piece of 1x2 between the 20” long 1x6s. This is the support for the back of the hood. d. Attach the fluorescent light to the inside of the front of the hood. e. Attach the 33” x 21½” piece of sheet metal to the top of the hood with ⅝” long wood screws. I placed them about every 5”. f. Put the hood on the work surface and mark the spots where you want to attach the hose clamps. These will secure your hood to the shelving unit. g. Open the hose clamps and straighten them out. h. Drill pilot holes through the hose clamps and into the sides of the hood. i. Screw the hose clamps in place with ⅝” long wood screws. 5. Finish the hood: a. Tighten the hose clamps so their diameter is about 1½”. b. Slide the hood onto the shelving unit so each hose clamp is on a support. Put it on the work surface for now. c. Put the top shelf on in the highest position. d. Slide the hood up as far as you can so it is directly under the top shelf. e. Tighten the hose clamps. You want them as tight as you can get them, because they are holding your hood in place. f. Slide the acrylic sheets on each side of the hood. If you have a small gap between the work surface and the side of the shelf, slide the sheets into this gap to keep them in place. g. Screw the acrylic sheets in place. h. Put the 35” x 24” piece of sheet metal on the back and screw it in place. i. (Optional) Seal all the seams inside your hood using foil tape. 6. Attach the fan: a. Make a hole in the side or back for your fan. The hole should about ½” from the top of the hood. Mine goes in the side, through the wood and acrylic. I don’t have any recommendations on how to cut the sheet metal, if you go through the back. Tin snips would probably work well. b. Tape the duct to the hole with foil tape. You may need to replace the tape periodically, but I can’t imagine it would have to be done more than once a year or so.
