Wow! All kinds of responses! Thank you, everyone!

Quote Originally Posted by Ken Nadvornick View Post
Which paper are you using for testing? I know some of them (Slavich, for example) specifically state that only red light is safe. For those I use a DIY 635nm red LED safelight.
I'm currently printing on Oriental, and it's OC-safe for over an hour with my Kodak D safelights.

Quote Originally Posted by Ken Nadvornick View Post
Your description sounds thorough and correct to me. Is your tape lifting up from the heat perhaps? Is it truly opaque? I suppose you could try temporarily covering the outside of the outer filters with some taped down red Rubylith. What you need to find is some level of baseline configuration that works so you can then work backwards from that to isolate the problem.
The tape isn't lifting and it's opaque; I just checked to see whether or not either could be a factor. I ordered some rubylith to see if that helps, but I don't have it on-hand yet.

Quote Originally Posted by zsas View Post
Ken's right, something sounds outta whack. Sorry to be mr obvious, but, any reason to not buy this? Sorry if you're aware of this, but if not...
I have seen those filters; I already had the gels on-hand and the diffusion plastic, so I was hoping to use them. Also, the rubylith I ordered only cost $10 for a rather large sheet.

Quote Originally Posted by Neal View Post
Dear Sundowner,

Probably a stupid suggestion on my part but are you sure the fogging is from the safelight rather than another source?

Neal Wydra
I'm pretty sure, Neal; I've had no issues with this paper in the exact same conditions, with the exception of the safelight change. That tells me that something, as we've discovered, is indeed in need of re-wacking.

Quote Originally Posted by Greg Davis View Post
The filters are wrong. The pair on the moveable vanes should be two sheets of the Rosco #19 with diffusion, but the bottom pair should be a sheet of Rosco #3406 and #3407 with diffusion. This matches the filters that are sold commercially for this safelight.
That's different than what I've seen so far. Hmm.

Quote Originally Posted by Ken Nadvornick View Post
I dunno' Greg. For b&w all I use is a single layer of Roscoe #19 Fire between glass sheets without any diffusion. The Roscoe spectral transmission chart says this should be sufficient. And for both my CD and pre-flashed fogging tests of Ilford MGIV, it is.

This filter is located in the lower filter position. The vanes contain only sheets of black mount board. That allows me to adjust down to total darkness for easel framing and focusing.

This is more in-line with what I'd been reading; I was hoping to use the outer vanes to control the overall light level but I haven't made it that far, yet.

Quote Originally Posted by Mark_S View Post
Some thoughts -

1) Test Neal's thought that the fogging may be coming from something other than the Thomas Duplex - try a fog test with the light off, to make sure that your darkroom is dark when the lights are off.

2) I use an Agfa Sodium Vapour light - which is similar, but smaller than the Thomas Duplex. My lights take a long time to warm up, and until they are warmed up, will fog paper - I turn the safelight on 20 minutes before I start printing to allow it to stabilize - are you doing your test immediately after turning the light on?

3) Are there flourescent lights in the room (even if they are turned off). It may be that the light from the safelight is exciting the phosphors in the flourescent lights and they are emitting light which is fogging your paper.
1) Just now I tried one strip that was left out in the dark for eight minutes, and another directly from the paper safe; both printed perfect, unexposed white.
2) I let the light warm up for about ten minutes or so; I can try it after a longer time, though. That won't be a problem.
3) No fluorescent stuff anywhere near the darkroom, for exactly the reason you mentioned.