Sealing Metal Frames

[Dancinbaer]

I did a search for this topic but found very little. It was only "mentioned" as part of threads on dust covers which for the most part refered to wood frames. Soooo......

Do you seal metal frames, if so with what?
Do you use spring clips or shim the full channel?

Thanks,

[wpfay]

Denny,
If you mean sectional metal, I don't use the clips anymore. I cut foamboard strips (about an inch wide) to length and "stuff" the channel, I guess what you refered to as shimming.
I don't consider this to be preservation grade, but I usually am not putting items that require that level of framing in sectional metal frames. If I were, I would use the sealed frame technology that involves the use of Marvelseal and archival hot melt glue to make a "hermetically" sealed package to insert in the frame. I would then use various support boards: polyflute, acid free corrugated, 1-2-4-ply rag, acid free foamboard to fill the channel of the frame so no clips and/or shimmimg would be needed.
Hope this helps.

[preservator]

If you take apart a sectional frame that has been use for some time, you are likely to find that the
backing board and mat have warped away fromt the
glass in between the spots where the clips have
been. That means that dust can enter the mat package in those areas in which the backing board
has warped. The use of foam type board to "shim"
stuff, or pack the edges is far in all ways superior to the pressure clips. Some of these
strips of board should be left exposed beyond the
hardware channel, so that they can be pulled out
when the frame is taken apart. If a higher degree
of seal is required, one can follow Wally's suggestion and use a highly sealed package or
one can tape the edges of the glazing/mat/backing
board package (having first masked the edges of
the package with strips of foil laminate material
such as Marvelseal 360.

Hugh