Heated Cabinet Workshop Projects
This is a project for those of us living in areas where it gets cold during the winter. Where I live, it can easily get down to -30 degrees Celsius, or colder for about three months out of the year. That’s more than cold enough to freeze glue and water based finishes, if they are left in an unheated shop. Even if your shop is heated, it may not be kept up to ‘room temperature’ at all times. Mine, for example, is kept at about 10 degrees C, when the heater is working…
Wood glue works best at room temperature, or around 20 degrees Celsius. In the past I would bring it in the house just to keep it warm enough to use. This is a bit inconvenient, especially since I use more than one type of glue and have a few finishes that I regularly use in the shop as well. To tote these back and fourth for every project is not pracstical, so I came up with a solution that works well: a wall-hung storage cabinet that is heated with an ordinary light bulb. The bulb is controlled by a thermostat that allows me to set the ideal temperature for the inside of the cabinet.
To get started, I cut out the top, bottom and sides for the cabinet from 3/4″; thick plywood:
The sides are 1/2″; wider than the bottom and top.
A 1/2″; x 1/2″; rabbet is cut in the back edge of the side panels:
When the sides are nailed and glued to the top and bottom, the rabbets make space for the plywood back panel.
Cutting the back to size using my saw board:
The back is just 1/2″; spruce plywood, glued and nailed in place. For most workshop cabinets that I would mount on the wall, I would leave the back open. In this circumstance the cabinet needs to be sealed up as tight as possible to keep the heat in, so adding the plywood back is important.
It’s at this point in the assembly process that I realized that I forgot to make shelf pin holes in the side panels before putting it together. Rather than try to take it apart, I came up with another way to support the shelves. The first step was to cut shallow rabbets on the ends of each shelf:
The rabbets are 1/4″; wide, 1/8″; deep.
To hold the shelves up, I cut pieces of 1/4″; plywood to the right width and height, and these are just held in with the rabbets on the shelves:
Not a bad way to do it, I think. If I need to change the height between shelves, I will have to cut new pieces of 1/4″; plywood. It isn’t the most convenient way to change the height, but I don’t think I’ll have to do that very often, or at all.
All of the shelves installed to check the spacing. The bottom one is fixed, glued and nailed to the sides and back panel:
Next, I need to get it off of my table saw and onto the wall, so that I can finish it. I made two legs to set the cabinet on to hold it up in the right place on the wall:
Then I used a nail as a stud locator behind where the cabinet will go. The cabinet will be heavy and needs to be screwed into solid structure.
With the upper shelves removed, I got it screwed onto the wall. It’s a lot lighter and easier to get it up on the wall when it’s only partially finished:
Then I put the shelves back in.
Next, I added a face frame:
3/4″; thick spruce, glued and nailed. The stiles are 1-1/4″; wide, the rails are 3/4″;, to match the thickness of the plywood.
With the face frame applied, the shelves come up short of the front, leaving a 3/4″; gap for the heat to circulate up from the bottom of the cabinet.
With the major work done on the cabinet, I turned my attention to the ‘heater’. Here I’m cutting out a piece of plywood for a standard octagon box:
An inexpensive lamp holder will go on this box after it has been wired and put in the cabinet.
To control the temperature, a thermostat is used, and here I’m cutting out for the box that it will be mounted in:
Since heat rises, it makes sense to put the heater at the bottom of the cabinet.
A hole is drilled to run the power cord in:
The wiring is very basic and I’m using pieces of an old extension cord:
Testing it out before I close it up to make sure I didn’t make and mistakes. Seems to work well. Note that for the test I used a CFL bulb, but when the cabinet is in use it will have a regular long life incandescent bulb, since it’s heat that is needed, not light. As for wattage, I wouldn’t use anything above sixty watts in this enclosed space.
A cover goes on and a divider (arrow) to block some of the heat from giving the thermostat a false reading:
Without the divider, the heat from the lamp would reach the thermostat too quickly and it would turn off before the rest of the cabinet warmed up.
Next, the cabinet needs a pair of doors to keep the heat in. These will be solid 3/4″; plywood and weatherstripped, to stop air movement. The hinges I want to use are a bit too open, and won’t let the door close tight enough:
Squeezing it closed in my wooden vise does the trick.
Bending the hinge like this can make it a bit stiff, but it will loosen up fairly quickly.
To avoid doing this, the hinges could be mortised into the door and face frame of the cabinet, but I didn’t feel the extra work was warranted
I’m using three hinges per door, to make sure it closes tight against the weatherstripping to make a good seal:
Both doors hung and fitted. They line up well on the face and there is only a very slight gap between the doors.
To hold them closed, I made a simple spring latch:
This is very similar to the latch that holds the dust bin onto my homemade band saw.
The doors need handles, so I made these from solid wood:
These are just glued onto the face of each door:
Weatherstripped and finished:
I still need to make a sheet metal shield to fit around the bulb to stop it from getting broken if something hits it.
It has worked well, so far, keeping the items inside toasty warm. Even when my shop heater failed and it got really cold, it still kept the glue at room temperature. The cabinet is not huge and won’t hold a lot, but there’s more than enough space for the important things.
A project that was long overdue and well worth building.
It’s been a full year since I built the cabinet and it really served me well through last winter. During that time, the only problem was to keep a working bulb in the unit. It would burn out fairly often and I had to keep checking it to make sure it still worked. It was suggested that it be replaced by a ceramic type heater bulb used for terrariums. One of those would last a lot longer, but I never got around to buying one.
Another problem is that where the bulb is, directly above it a dark spot formed on the plywood:
Like a scorch mark, but I don’t think there is any real risk of fire. Originally, I was going to make a metal shield that would protect the bulb, and that would have worked as a heat shield as well, preventing this from happening. To temporarily ‘fix’ this, I drilled a 2-1/4″; hole directly above the bulb:
That way, the heat goes directly up through the hole. This worked well, but I still had the bulb burning out problem.
While talking about this project in a forum topic, I came up with another idea for a heat source: a small hair dryer. When I moved into my new house, there happened to be one on a high shelf in the bathroom that the previous owners left behind. It is a perfect fit:
I made a holder for it and put an end on the cord that was powering the light fixture to plug it into. I also cut a larger hole at the end of the shelf for the heat to come up through, with the smaller hole that was drilled for the bulb as an intake.
It has been in place and running now for about two weeks. The hair dryer has several advantages: First, it has a fan built in to quickly circulate the heat, unlike the bulb. It also has more power to heat the cabinet when it gets colder. As it has more power, it stays on for a shorter amount of time and there is no risk of scorching the wood. Finally, it has built in thermal overload protection, and will shut down if it gets too hot.
The one I used is 1500 watts and has two fan settings. I set the fan to the lower setting.
As usual, this project is “;use at your own risk”; and should only be done if you are man enough to accept responsibility for your own actions. If your shop burns down as a result of building this cabinet, that is your own fault. If you have any doubts, don’t do it – bring your glue, paint and finishes inside your house to keep them warm.