Regulating my oven?

[MervA]

My oven fluctuates between 120 and 190 Degrees Is this bad or Can I make it more consistence by changing the light bulbs?    

[Robertfishes]

I built my oven following the Bingham's plans. I bought item 2TC from Them for about $9.00.. Binghams called it a thermostat control, it shuts lights off at 180 degrees and back on at 150 Degrees..I have heard others call it a snap disk.

[Buffalo John]

Sounds like a furnace limit switch.

[milehi101]

The discs you are talking about are used used to
control the temperature in dryers.  You can buy them from almost any place that sells used appliances. Their are numbers on them that will say L140 L150 ect  the numbers are the high temperature they open at.  I use a L185 in mine and my box and wire it in series with the lights.  My box maintains a temperature of 180 hi and turns on at about 165.

[monterey]

I also use the Bingham thermostat and it works fine.  My oven is plywood with four 200 watt bulbs and lined with 1/2 inch of alum covered foam.  

I see that some guys use an internal circulating fan to keep heat even in the oven and aboid hot spots.  I plan to use one from now on.

Just another example of the great information exchange that goes on every day on this board!  

[MervA]

Thanks guys
I too built my hot box with bingham's plans maybe my snap disk is messed up

[JamesV]

my heat box has 8- 100 watt bulbs, in the winter I use all 8 and in the summer I use 6. My shop is not heated. Mine averages 180, but I don't think a wider range would be a problem.

[bowhntineverythingnh03743]

Hey guys... I am new to the hot box building. Just finished mine... I plan on running 4 100 watt bulbs staggered on the lid of my box. You can actually see my box in the "What did you do today" on page 158 I think. I just purchased one of the thermo switches but have no clue on wiring the box up. I mean I got the basic idea but don't know how or where to wire this in. Can any of you help with pictures and an explanation.

Thanks Justin

[bjansen]

When I built my last hot box I bought a digital temp controller and it was well worth it.  With a couple clicks of a button I can set a precise temp and the controller will regulate it.  The one I bought is a Ranco ETC ($50)

[Beanbag]

I just finished up a small foam box 4'x 2'x 2' for take downs. I am using 2 aluminum drop lights (act as heat diffusers) with 100 watt bulbs that I clamp to the top of the form facing up with a small computer fan to circulate in the bottom. I use 4 thermometers to check temp. This set-up runs about 200 ( this oven thermometer might be off a bit) at the top above the lights and 150 -160 at the level of the limb. Kind of a Ronco "set it and forget it". This is in my basement so the temp is pretty stable. I tried different bulbs till I got it stable. KISS method.

[typical2]

I just ordered the Ranco digital thermostat.  The ability to turn it up to 180 for the laminated riser and a bit lower for the glue up has my interest.

[LC]

I've used both a snap disc available at any heating ventilation supplier. Some even have a adustable screw for temp control. They all seem to have a 20 degree variable for off to on. To be honest I don't think thats a problem. I've also used a bulb type temp controller. A little closer temp control.

The idea of a fan inside the box circulating the air does interest me. It's the same theory of a convection oven. It probably does help alot. But the bottom line is if your using a oven with light bulbs baking for 5 hours  I'm not sure it's worth the effort. To be honest if your using a oven with fans, convection heat, you proably could reduce your oven time.

[talkingcabbage]

I use an old wood stove thermostat.  It's adjusted with the tightest range I can get, and it fluctuates about 35 +/-.  I don't think that's a huge issue, at least I've never had problems with it.

As far as wiring, run the main power wires into the thermostat first, then out to the lights.  White to white, black to black.  Easy cheesy.

[Big-un08]

Here is another vote for the Ranco ETC. I installed one when I built my oven, and have been totally spoiled. The unit is designed to keep you within a couple degrees of your desired temperature. Without the variation in temperature, I cook mine for 1.5 hours and then cool them down to room temp. Haven't had any problems yet.

[typical2]

I installed the Ranco digital thermostat and it is working great.  I also put in a circulating fan.  Stays within a couple of degrees with no hot spots.  I am liking it.

[typical2]

The digital thermostat with a small circulation fan do a great job maintaining a constant temp everywhere in the oven.  Great way to do it.

[Greg Owen]

I have never built a bow or an oven, but one thing to remember is that the bow and bow form has much more mass than the air. The air will have a wide range of temperature variation where the bow form and bow with its mass will not have the same drastic temperature variations. Measure the temperature on the bow form instead of in the air.