Dry Mount Problems...Please Advise!

[jovo]

I've been dry mounting my prints for several years now, and use Beinfang BufferMount tissue in a Bogen press large enough for 16x20 prints. (I only rarely mount prints larger than those on 11x14 paper.) I heat the press to the nominal 170ish degrees, and put the print in for a minute and a half. I preheat the mount board and print separately for a minute or so to be sure they're dry, let them cool, and then put them in the press. The studio is usually not humid at all, and in fact is quite arid in the winter. They usually come out quite well, although there are sometimes a few bubbles that I press out with the tacking iron.

The problem that has arisen is that several boxes of mounted, framed prints that have been stored in the garage are showing significant bubbling that hasn't responded well to re-pressing to remove. Also, some prints that have not been framed, but kept in boxes that were open for a while in our bedroom that was being humidified at night with a humidifier have showed significant bubbling as well. However, mounted, framed prints from the same sessions that have been on the walls since being mounted are fine.

What's wrong? Is there a limited range of temperatures that prints should be stored in? A limited humidity range? What if someone buys a mounted, and framed print for their vacation home that isn't heated in winter, or air conditioned in summer? Am I doing something wrong with my process?

I'd greatly appreciate some advice as I have a show going up at the end of March and don't want to offer prints for sale that may not remain in the condition in which they were purchased. Thanks for your help in advance.

 

[Mainecoonmaniac]

Have you ever thought about not dry mounting your prints? How about using mounting corners?

 

[Shawn Dougherty]

I have stored prints in less than ideal conditions without issue... The only signifigant difference I see between your process and mine is that I mount at a little over 200 degrees F and use a release paper over top. I have never experienced bubbling.

Sure hope you get this figured out, John!

All the best. Shawn

 

[martyn1]

I would also offer that when mounting prints I too use a temp of approx 190F.
I live on the gulf coast where it's very humid and have never had a problem, even in the hight of summer.

 

[tim k]

You might give some thought to checking what the "real" temp. is inside the press. I checked mine the other day and it was off by 50 degrees. The dial read hotter than it really was. Could be, that you never quite finished the job in the first place.

 

[Vaughn]

A little blurb I read about Beinfang BufferMount tissue is that "Activates as low as 175 degrees Fahrenheit." So it sounds like you might be a bit cool.

Also it bonds while cooling -- not in the mount press. So I have a very clean flat surface I place the hot mounted print facedown on -- then rub the back of the matboard to provide pressure while it is cooling.

If the glue on either side of the tissue fail to fully melt, and if the print/tissue was not in tight contact with the matboard as it cooled, it might easily unstick when print and matboard absorbs moisture and swells at different rates.

 

[jovo]

Have you ever thought about not dry mounting your prints? How about using mounting corners?

When I started printing with RC papers years ago, I used corners. But FB paper curls and looks ripply in humid weather when using corners for prints larger than maybe 5x5 or so. That's why I dry mount. When it works well, the prints look terrific.

I'll try a probe, 'cause I've no reason to believe the temp gauge is necessarily accurate. I'll also try closer to 200 in case that's the problem.

Is there a secret handshake, dance, or incantation I didn't know to do either?

 

[jovo]

Also it bonds while cooling -- not in the mount press.

Oh, I thought that was Color Mount that bonded as it cooled, and not BufferMount. But, pressure as you describe is easy enough to do after the print comes out of the press, so I'll try that as well. Thanks.

 

[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.

 

[Merg Ross]

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....

Yes, BufferMount tissue. Note that I have never tested the heat on my press for accuracy, so the 225 may not be so; however, this procedure has worked for many years. Also, the two ply board may lower the actual temperature at the print surface.

I do believe that adhesion at the cooling stage may be the problem. Rolling gives better adhesion than weight alone. Anyway, what works for me may not work for you, but it is a thought. Let us know what you discover.

 

[Curt]

One note, I use Seal release paper on top of the print and under the mat. It's a big sheet that I folded in two and I put the tacked print in it to press.

 

[Mr Bill]

If I were having problems, I'd go back through Henry Wilhelm's book. Specifically, Chapter 11, starting on page 378, "How to Determine the Ideal Mounting Temperature."

Dead Link Removed

Obviously the book is a bit out of date, but there is a good discussion of the issues.

 

[jovo]

If I were having problems, I'd go back through Henry Wilhelm's book. Specifically, Chapter 11, starting on page 378, "How to Determine the Ideal Mounting Temperature."

Dead Link Removed

Obviously the book is a bit out of date, but there is a good discussion of the issues.

Sounds like a terrific resource. I didn't even realize that Wilhelm Institute had done testing on pre-digital materials, so I wouldn't have though to look there.

 

[jovo]

Our show is now up on the walls at the Wallkill River Gallery in Montgomery, NY. It took a long time to hang, but it looks really good! My thanks to all who offered such useful tips for drymounting success. I learned a lot, and the print mounting looks better than I've ever achieved. The key has been proper adjustment of the press temperature, pressure in the cooling stage, and using a roller to exert the pressure. I am able to exert far more "weight" with a roller than I'd have been able to with a pizza stone, or other large flat object, and the technique will work for prints much larger than any flat object I could even lift that would cover a print completely. Thank you all, again!

 

[Merg Ross]

Congrats on the show!

Glad the tips helped, and thanks for the feedback.

 

[George Collier]

Hi John - nice show poster. You seem to have gotten your mounting issues worked out. I used to dry mount everything, but have lately been discouraged from this by framers and gallery folk. However, having just read your thread, I could mail you some testing strips that are mentioned in one of the posts. I used to use them with Seal MT-5, the tissue of choice some decades ago. If I'm not mistaken, they target a temperature of 210, ideal for that tissue. There are two colored patches, if one is melted after the mounting duration, the temp is at least 200 or so, if the other one is melted, it is over 215 or 220, I forget the specifics. Anyway - if you would like some (I have a lifetime supply somewhere that I will probably never use up), PM me with your address and I'll stick some in an envelope.