light box temp time

[mountaineer2]

I just finished a heat box with four lights in the bottom(100W). I foil lined it with bubble insulation from lowes. I turned it on and after 1 hour the box still only reads 120F.
So,,, My question is how long does your light box take to heat up? and what watt light bulbs and how many do you guys use?
thanks in advance.

[matts2]

how big is your box.  It shouldn't take that long I wouldn't think.

[D]

I lined mine with the same bubble insulation that you used but I used 6 100 watt bulbs and after and hour mine was at 190 degrees.

[mountaineer2]

thanks for the replies
 
the size is 83" x 12" x 32"
with 3/8" thick plywood
I think the 3/8" plywood is the mistake.
I am going to try 200watt bulbs tomorrow.

[matts2]

I had two 200w bulbs in my 16x16x80 all foam box and it got up to 180 in 20 minutes.  They get real hot.  Make sure you don't have the plastic fixtures.  I made that mistake once with 200w bulbs..

[clayton95]

It might be the bulbs you are using.  Some are made to be cooler than others.  My dad always uses the clear industrial bulbs and they get hot pretty fast.

[Dick in Seattle]

I'm also lined with the bubble insulation, but my box is smaller, 78x12x24, bulbs at top.  I used only three bulbs because of having to shorten the box to fit my space.  I used the ceramic fixtures and clear industrial bulbs.  I got a selection of 100, 150 and 200 watt and was able to balance the heat quite well by varying the bulb mix till I got what I wanted.  This was BT (before thermostat).  The box heats right up empty, but takes a good 45 minutes to get up to 160 with a from and bow in it because I use an aluminum form and lots of iron clamps.

[mountaineer2]

thanks again . I will try some different bulbs and see if that helps.

[Savage]

My box is around 4' long, lined with foam insulation board and has 2 200w bulbs. Gets to temp in about 10 minutes.

[mountaineer2]

150 watt bulbs fixed the problem .thanks for the help.