Transparent Covering for Electrical “Closet”

[angus99]

I need to fashion a cover for the electrical “closet” in the ER which houses bus bars, terminal strips and many dozens of electrical connections. The original cover for this area was plywood, but I want to go with something that will allow me to see inside without removing a lot of screws. I’m also hoping that I can use a Flir camera, with the transparent cover on, to detect any warmth inside indicating a loose connection, etc. I can pretty much check any circuits this way on the boat except for this closet when it’s covered with plywood.

So what material would be best, polycarbonate or acrylic?

Thickness, I assume, will also matter here (not to be confused with the current TF thread on “length”). I assume the thicker the material, the less heat will be detectable by the Flir. An alternative would be to make the whole thing easily removable and shoot it uncovered from time to time with the Flir.

So has anyone done anything like this and what did you use?

 

[rslifkin]

Is there enough space to make it hinge open? If so, I'd do that regardless of material.

 

[GoneFarrell]

Search: flame retardant polycarbonate sheet. Better properties than acrylic. Transmissibility in infra red spectrum should be adequate for your sensor.

Hinge it or hang it on keyhole slots.

Any good plastic supply house should be able to route it out for you, the stuff can be problematic to shape at home.

 

[Alaskan Sea-Duction]

Probably more work than what you want to do, but I have seen electrical panels when you open the door, all the circuit breakers and switched light up. Then the panel swings back to allow you access to the back of the panel. The first one I saw blew me away.

 

[O C Diver]

Here's mine:



A piece of lexan from Home Depot or Lowes. The base is threaded. The screws go through the lexan, a couple of aluminum stand off tubes, a nut,and then screw into the base. Pretty quick to remove with a screw driver.

Ted

 

[C lectric]

I use Lexan. It is fire resistant. It will burn if a flame is held to it but will go out if the flame is removed. It is also tough and flexible enough that a slight bend can be used if need. It , like acrylic, can be worked with standard woodworking tools.

If you hinge it don't overtighten the fasteners, Snug only enough to hold in place and slightly overdrill the holes. Jamming a screw of any type through a too small hole will or may cause cracking. That goes for any plastics like polycarbonate or acrylic.

 

[angus99]

Thanks, all, for the good ideas. I’ll probably go with Lexan ($$$) and secure it with hanger bolts and star knobs for quick removal. Will post final install.

 

[tiltrider1]

Polycarbonate will expand and shrink less than Acrylic(less likely to split at screw holes). It is also less likely to break than acrylic. Polycarbonate scratches much easier than acrylic and deteriorates quicker in UV. Neither of which matters in your engine room.

 

[rgano]

Thanks, all, for the good ideas. I’ll probably go with Lexan ($$$) and secure it with hanger bolts and star knobs for quick removal. Will post final install.

Possibly frame in wood for a bit of strength?

 

[kchace]

Lexan and trade named items such as Macrolon are both polycarbonate - this is what you want. Very hard to break and can even be bent with or without heat. What I would not suggest are things like "Plexiglas" which are acrylic and easily broken.


Ken

 

[Larry M]

Ian: You mentioned hanger bolts for mounting plus knobs. If you use those or something else, allow for expansion and contraction. With the temperature swing in the engine room, over drill all your mounting holes. Tiltrider1 mentioned that previously and I learned the hard way when the sun hit a panel I mounted.

 

[Duvie]

I did a test some time ago with Polycarbonate. I bent a 1/4 inch thick piece 90 degrees in a vice. It was 5 below zero and I did this using a sledge hammer. No breakage. So I don't think drill holes will be an issue with splitting.

 

[Coyote65]

You can use a cement drill for your holes twist drills can cause cracks, like others have said drill the holes oversize. Do not tighten the bolt/screws/nuts very tight as it stresses the plastic causing cracks. Replaced all the windows in a B-17 and used the above suggestions and never a crack.

Terry

 

[angus99]

Thanks, all. I found a local source for Lexan that charges a small fraction of the best on-line price. So, just waiting for the hanger bolts—which I’ll drill oversized holes for—and Robert’s my father’s brother.

I’ll post pix when I finish this in a week or two.

 

[Fletcher500]

Will the lexan affect the FLIR IR camera readings when shooting for loose connections? I assume it wouldn’t, but not sure.

 

[angus99]

Will the lexan affect the FLIR IR camera readings when shooting for loose connections? I assume it wouldn’t, but not sure.

Great question. I’ve read it both ways—depending on the thickness of the covering—so I’m designing this with star knobs for easy removal . . . just four of them. It will be a nice bonus if the FLIR can read temps without removing the covering.

 

[GoneFarrell]

Years ago I helped design the enclosure for a laser beam reticle writer. It had smoked lexan windows, about 1/4 inch thick.

We couldn't look close through the windows when it was running, even though we were in clean room suits, because the infrared from our faces was enough to mess up the metrology on the machine. So I think you will be OK.

Test it in the galley at a warm burner.