Airtight cabinets

[Prashun Patel]

I am making 2 photostability chambers for work. This is a fancy way of saying plywood cabinets with a heater and thermostat and a couple bulbs inside.

In order to keep the temperature as constant as possible, I'd like to make the doors fairly airtight.

Has anyone used refrigerator-style magnetic door seals on a cabinet? I am not above lining the face frame and door back with any necessary steel to get these to work.

Any other ideas? weatherstripping and a latch? I'm saving a lot of money by building this, so I don't mind spending a little extra on components that won't peel off in a year.

What's the right way to go on this?

BTW, the thermostat/heater part is so cheap to make, I'm considering making a lumber or bowl kiln this way.

[cody michael]

I bought door wheather stripping that is a piece of metal about 1 inch wide with a small rubber weather stripping on it. they seem way better then the foam stick on stuff.

[Larry Edgerton]

I use these guys seals on exterior doors. Tight and very easy to work with. You will need to prepare your cabinet before assembly as they fit in a kerf.

http://www.conservationtechnology.com/building_weatherseals.html

Larry

[Pat Barry]

What temperature are you shooting for within these boxes?

[Prashun Patel]

Pat, I'm shooting for 40-45C, so 110-120F. Not that high.
I'll run some experiments with an uninsulated cabinet but am prepared to insulate the panels if it'll prevent the heater from cycling every 20 seconds.

Larry, thanks for that link; that's exactly the kind of picture I was hoping for.

Cody do you have a picture of your installation?

[cody michael]

Pat, I'm shooting for 40-45C, so 110-120F. Not that high.
I'll run some experiments with an uninsulated cabinet but am prepared to insulate the panels if it'll prevent the heater from cycling every 20 seconds.

Larry, thanks for that link; that's exactly the kind of picture I was hoping for.

Cody do you have a picture of your installation?

I haven't installed it yet. its on my to do list, my inlaws have it on there door, seems to work well.

http://www.zoro.com/value-brand-door-jamb-weatherstrip-7-ft-l-2rrn4/i/G0678894/?utm_source=google_shopping&utm_medium=cpc&utm_campaign=Google_Shopping_Feed&gclid=Cj0KEQjwyIyqBRD4janGs5e67IsBEiQAoF8DGs9MMrdf 8xyosS1E8zSlmaWYqnc9dWCPfZAoJoYlyuQaAv5M8P8HAQ&gclsrc=aw.ds

that is what it looks like

[Jeff Duncan]

I'd probably try lining the box with some 1/2" foam insulation board and use a self-adhesive Pemko silicone bulb type weatherstrip for the seal. You'll also need a simple latch of some sort to compress the bulb a bit for a good seal. Not only will it be simple to build, but should be pretty efficient.

good luck,
JeffD

[Pat Barry]

Pat, I'm shooting for 40-45C, so 110-120F. Not that high.
I'll run some experiments with an uninsulated cabinet but am prepared to insulate the panels if it'll prevent the heater from cycling every 20 seconds.

Larry, thanks for that link; that's exactly the kind of picture I was hoping for.

Cody do you have a picture of your installation?
At that temperature a simple adhesive tape mount should be fine. Make it a compression seal with some type of closure latch. I would be suspicious of the refrigerator style with an adhesive though. That might be too hot for the adhesive long term

[Kent A Bathurst]

Prashun -

maybe info overload, but..........spend a few minutes comparing your mental picture to the different items available here - -

Some are just the weatherstrip profile, some are mounted to metal [alum, etc.].

I would think you want to look for neoprene bulb wtsp - compressible, great seal.......but there may be a different profile that fits your needs better.

there a bunch of stuff on this page - see the list on the left - - - good luck!!


http://www.mcmaster.com/#neoprene-weatherstripping/=wzuu5u

[Jamie Buxton]

Have you considered repurposing an old fridge? The failure mode of most fridges is that the moving parts fail -- that is, the compressor. The insulated box is still insulated. I see them standing by the road side with a big "free" sign on them.

[Prashun Patel]

I have, but i need two and they need to match.

[John Stankus]

My first instinct was to suggest using desicator cabinets if you need airtight. Are you trying to measure photo degradation of materials? If so you may need to account for getting rid of heat from the lamps. Lamps in a small enclosed space can quickly heat that space up. So this could be a cooling and temperature control problem

John

[Derek Stockley]

I had a cabinet with an overlay door, weather stripping and a latch on it for a while just to keep the dust out, and it worked well for a while. Then the door warped and the seal was no good. My door was a pretty ordinary 5-piece door design with a veneer core ply panel. You might want to consider warping as you design your door because I suspect the temperature difference is going to increase the tendency for it to warp. If I were doing it again, I'd probably use a simple particle core melamine slab door.

[Greg Sznajdruk]

I've built a similar box to keep glue; battery operatedmeasuring tools etc. in the shop over winter. Mine is plywood lined with 2 inchpoly styrene. The door interior is also line with 2 inch poly styrene thedoor fits into the 2 inch poly lined walls giving a large surfacearea to act as a seal. Don't know if it is air tight but would guess itwould be pretty dam close.

Greg

[Frank Pratt]

If keeping a constant temperature is important, then you should consider using an electronic electric heating thermostat. They don't switch the load on/off as they cycle. As the temperature falls they gradually apply more voltage to the heater as required & then lower the voltage as the set point is maintained. They typically will maintain the temperature to within less than 1/2 a degree, which a standard thermostat won't come close to doing.

They won't work on a heater if it has a fan though.

[Prashun Patel]

Thanks for the thoughts on warping. I may now use mdf for the door and face frame.