Dry Mount Problems...Please Advise!

[jovo]

... and use a release paper over top. I have never experienced bubbling.

Actually, I do that too except I use parchment paper (bakery section of the supermarket) that does the same thing but is far less expensive and is made for oven temps.

[Curt]

Is it the Bogen 550 press? What pressure do you have the press set at and is the temperature you set really what you get? I've go the same press it sounds like and I once backed off on the pressure set to store and for a while when I moved. I later dry mounted a print and it looked fine but then at an angle it had spots that weren't pressed down, like bubbles. Check the mechanical setup and temperature control on the unit.

Check out this article from J.B. HARLIN who has contributed here I believe, he is very sharp with photographic mechanics.

http://www.jbhphoto.com/articles/dmadj/dmadj1.htm

There are temperature strips that can be placed in the press but I haven't used them, maybe someone can give a source for them so you and the rest of us can do a checkup on our presses. Good luck and I hope your previous work is recoverable.

Curt

[Jon Shiu]

I had a problem with my Bogen press due to only one side getting hot. Turns out the heating element had broken in two, so only one side was heating up. So check different areas of the press for temp.

Jon

[BetterSense]

When I mount prints with a clothes iron, I use a good thermometer to measure the surface temperature of the iron. 180 degrees works, but not well. I use a temperature of 200-220 degrees. I'm sure there is some "temperature loss" at the tissue level.

[jovo]

...Is it the Bogen 550 press?

It's the Bogen 560. I've just now put an oven thermometer probe in the press with three pieces of mount board on each side of the metal probe (a round rod) that equals the diameter of the probe, and keeps the top of the press level as well. The measured temp of the press was 205 f so I've backed it off a bit trying for about 190. I also use a piece of mount board on top of the pad to help with the pressure since I've not ever been able to really change it with the adjuster (I suppose it's an adjuster) on the top of the thing. I'm also pretty sure that the heating element is intact across the top of the unit. We'll see, now what happens.

(btw, when I was using Colormount tissue, I used a pizza stone as a weight after pressing.)

[BetterSense]

I've always wondered about using a pizza stone or piece of granite as a dry mount press. It seems ilke you could put it in the oven for a "long time" at 200F or whatever, and then just set it on your picture and leave it.

[Merg Ross]

My guess would be a combination of temperature, and pressure at the cooling stage of the process. I use the same tissue with my Seal Press set @ 225 degrees (nominal) with a two ply board over the print. Press for 1 1/2 minutes, and then comes what I consider the most crucial step, as the tissue adheres at the cooling stage. With a piece of two ply board over the print, I use a hard rubber roller and firmly roll over the print for at least 30 seconds, exerting pressure. I have never had the problem that you describe, although my prints are not subjected to severe climatic extremes. Hope this helps.

[jovo]

My guess would be a combination of temperature, and pressure at the cooling stage of the process. I use the same tissue with my Seal Press set @ 225 degrees (nominal) with a two ply board over the print. Press for 1 1/2 minutes, and then comes what I consider the most crucial step, as the tissue adheres at the cooling stage. With a piece of two ply board over the print, I use a hard rubber roller and firmly roll over the print for at least 30 seconds, exerting pressure. I have never had the problem that you describe, although my prints are not subjected to severe climatic extremes. Hope this helps.

Thank you, Merg. Do you use BufferMount tissue? It's interesting that you are using a hotter press than I am...I guess I'll have to try both 190 (which I now have it set for) and your 225. The roller, and top 2 ply board sounds like yet another good idea to apply.

Perhaps I need to add that the print usually looks great after it's come out of the press. It's only later that the bubbling either occurs or doesn't occur which suggests, as several of you have observed, that the tissue didn't adhere completely. Hmmmmm....

[Jon Shiu]

It's the Bogen 560. I've just now put an oven thermometer probe in the press with three pieces of mount board on each side of the metal probe (a round rod) that equals the diameter of the probe, and keeps the top of the press level as well. The measured temp of the press was 205 f so I've backed it off a bit trying for about 190. I also use a piece of mount board on top of the pad to help with the pressure since I've not ever been able to really change it with the adjuster (I suppose it's an adjuster) on the top of the thing. I'm also pretty sure that the heating element is intact across the top of the unit. We'll see, now what happens.

(btw, when I was using Colormount tissue, I used a pizza stone as a weight after pressing.)

I think if you use mat boards on top of the print you need to press for a longer than normal time. I think the seal press comes with instructions with a chart for how much longer.

Jon

[jovo]

I think if you use mat boards on top of the print you need to press for a longer than normal time. I think the seal press comes with instructions with a chart for how much longer.

Jon

John, you're right, but I was just trying to find a way to use the oven thermometer to measure, so the mat board scraps were beside the probe, not on top of it. It doubtless screwed up the pressure, but I was only trying to find the temperature.