Dry Mounting Problems

[Peter Lewin]

My frustration with "hit or miss" corner adherence (if that is a word) has reached the point of asking for help! I used to love MT-5 which adhered under heat; I have a love-hate relationship with the Archival tissue which adheres during the cooling cycle. (I could probably just change to Colormount which I think is also heat-adhering, but at least philosophically I like the archival idea.)

First: equipment - I have a Seal 110s press, which has the 12x15 platten. I'm mounting 11x14 trimmed prints (so they are slightly smaller than the nominal size) which obviously doesn't leave a lot of leeway in placement in the press, but I try to be careful and make sure that the platten covers everything. The problem I'm having is that randomly I get one or more corners not sticking. I've tried a variety of approaches (please bear with me, just trying to provide as much info as may be relevant).

Originally I would sandwich the mount board (2-ply) and tacked print in-between two more pieces of 2-ply, and when I removed the mounted sheet, quickly place it under a heavy glass sheet (since I never owned a proper Seal "iron plate," the 20x20 is currently listed as special order at B&H, $280). I experimented with temperature and time, and no matter what, got inconsistent results.

Since I never had a problem tacking the mount tissue, I thought I would try to see how close I could get to that approach. So I tried taking the top 2-ply off the sandwich and just using a sheet of interleaving tissue between the print and the platten, set the temperature to 175 for about 1'15", and then placed the mounted print under an aluminum baking sheet with filled 1/2 gallon containers as weights. Again, inconsistent results - sometimes good, sometimes the unstuck corners. Admittedly the baking sheet is again just slightly larger than the trimmed print.

So: would appreciate thoughts on technique, and perhaps a better idea for the cooling weight if the problem is that everything is so close to the print size so that placement has become too critical. Admittedly I get good mounted results if I go through multiple cycles for each print (i.e. keep trying until it finally works) but there must be a better way!

[Phil Hudson]

Maybe the press is not so hot in the corners?

[Kirk Gittings]

First I would pre-heat the mat board to drive any moisture out of it. Moisture is the enemy of dry mounting. For a cooling weight I use a sink cut out from a granite counter top. I got mine for like $5 from a stone counter company. To move it around securly, I then epoxied a 1x4 onto the the rough side and screw a couple of handles to that. That granite sucks the heat right out of a dry mounted print/mat board and keeps the edges down.

[Erik Larsen]

If you're not in a hurry, just leave it in the press till it's cooled enough to set up. I've done that for years but if you have many prints to mount it isn't too practical. If the corners still lift after that I would look at my bottom foam pad to see if it isn't making good contact like the center is.

[Drew Wiley]

Oh, there's nothing more "archival" about Archival Mount than other regular tissue choices. That label simply means, 1) The print can be removed later by re-applying heat, and 2) it is pH buffered distinctly alkaline, which is not in fact a good thing for every photographic print media. Regular tissue might do a better job simply by isolating the print chemically from the mountboard; and even this is redundant given the fact that most of us use stable Museum Board to begin with. I notice Wilhelm's old literature complains that drymounting prevents prints from being scanned, along with a picture of an ancient drum scanner the size of a washing machine. Now we (or rather, serious pre-press shops) have excellent repro-grade flatbeds, or maybe scanning copy cameras, capable of handling big flat originals, even attached to museum walls. In other words, I never saw much sense to Archival Mount being marketed to begin with.

[John Olsen]

I'll ditto Kirk's comment about running the mount boards thru the press beforehand to dry them out. I give 'em 45 sec each side with some airing out in between. I also re-dry the prints with two 20 sec heats and airing between.

For the mounting itself on the 110S, I set it for 220, using "buffermount" sheets. Press time is 2' 20". I used to run lower temperature and shorter time but the materials take more time and temperature since Seal sold out to Bianfang and then DK. You can feel the difference between the original Seal material and the newer DK sheets, so it makes sense that the process time and temp will be different.

I use an 8 ply board under the 4 ply that I mount to, a release sheet on top and a 4 ply under the platen. I let the mounted prints cool down for an hour under (dried) matboards with books stacked on top. (Avedon photo books seem to impart the best karma to the process.)

I arrived at these conditions thru trial and frustration.

But, I only mount 8x10s in the 110S. Before I got a larger press for the bigger prints, I would do the 11x14s in two press time: one time for the top half, rotate 180, a second time for the bottom half. I didn't trust the temperature to be even all the way to the edge.

This is fun, no?

John O

[Steve Goldstein]

But, I only mount 8x10s in the 110S. Before I got a larger press for the bigger prints, I would do the 11x14s in two press time: one time for the top half, rotate 180, a second time for the bottom half. I didn't trust the temperature to be even all the way to the edge.

John O

When you use this two-pass technique do you cool the first half under weight before heating the second half?

[Doremus Scudder]

I use BufferMount, or whatever it's called now with great success. In 35 years I've had about three prints that have had problems and those got remounted.

Here's my technique FWIW:

First, I don't use weights; it takes too long to lay the print down and get weight on it. After the boards have been dried previously in the press, I tack the print to the board. The press is heated and has a 4-ply board and a sheet of cotton-rag 1-ply interleaving in it heating with it. The press gets opened, one hand lifts the interleaving sheet and the print slides in between the board and the 1-ply (with the one ply on top). The press is then closed. After the requisite time (do test for this), the print is removed together with the sandwich of board and cover sheet. It slides out quickly onto the flat counter top at which time I use my cotton-gloved hands to press the print to the board while it's cooling. I pay attention to the corners and edges. After about a minute of cooling, I give the mat board a twist in both directions. if the print pops off anywhere, it goes into the dry-mount press again and the process is repeated. After a while, you'll get the right technique down and not have to return any prints to the press. This works fine for two-pass mounting as well.

The advantage to using the removable tissue is that mistakes can be easily corrected. For example, if the print is improperly positioned or the board later gets damaged. I've removed and mounted several prints (largely due to my mounting mistakes, i.e., getting the borders wrong) with 100% success. The board the print is removed from is no longer usable (unless you can cut a window mat from it), but the print mounts fine with new tissue.

FWIW, I sign all my prints lightly with pencil on the reverse before mounting so that, in the event that they ever need remounting by the owner, the provenance will be clear.

I've never tried the DryTac Trimount product, but after a quick perusal of their website, find the product interesting but it doesn't seem to be removable. I think I'll stick with BufferMount just for that reason.

Hope this helps,

Doremus

[John Olsen]

When you use this two-pass technique do you cool the first half under weight before heating the second half?

Sorry for the slow reply, I was out torturing some film in the mountains. No, just rotate it and stick the sandwich back in. I do gently support the half that's hanging out so it doesn't flex a lot.

[Drew Wiley]

"Archival Mount" is for low-temp application, and might indeed fail just from storage on transport in a hot climate, while MT5 in intended for a relatively hot press. I use Colormount, which is in between. But it's a combination of "dwell" time under pressure in the heated press and the actual temperature, which must be sufficient to begin with, and won't be unless you keep your press shut when not actually placing or removing things from it. Over time the thermostats can misread, so you might need to check the accuracy on your with a Seal melt test kit. And then there's basic technique, including properly predrying everything just before bonding. Some of these adhesives finally set under the cooling weight rather than in the press. I use a big sheet of heavy plate glass. Don't test the corner bond by flexing the board until it has thoroughly cooled first.