Positionable Mounting Adhesive Problem

naturephotographer

True Grumbler
Joined
Jul 5, 2001
Posts
60
Loc
Aberdeen, WA USA
About 4 years ago we mounted two wax rubbings using 3M pma. The customer just brought them in because they have little ripples where the adhesive has let go. Is there a way to correct this problem, other than using the little pma squeegee again?
 
If you have access to a vacuum press, you can apply a higher, more uniform pressure than you could with the squeegee. Depending on how big the ripples are, there is a risk of creasing them rather than flattening them.

Cold mount boards seem to respond to heat, as well, but so do wax rubbings.

If I were mounting a lot of these things (thankfully, I'm not) I'd look into the 3M ProMount system.
 
I would go with the squeegee again. You have two things working against you that could have been cured the first time around but now are probably too late. One, the "crayon" used in the rubbing has a high wax content that penatrates the paper and this process continues over time and can be excelerated by the display conditions. PMA will not work on a natural release such as wax for very long. Two, the paper is very thin and is usually streached badly by the rubbing process. When the papers "memory" comes back it has a compleatly different behavior compared to when it is new and is very unpredictable in how it will streach or shrink due to the enviroment.

I would go at it with the blue squeegee very carefully and see if there is any adhesive quality left to the PMA and to see if the paper will want to "gather" along the ripple forming a crease. If it does, stop and the only real answer then is to release the whole thing (while saying your favorite prayer to the framing gods), clean any PMA fromt the back, dampen and flatten it then low temp. mount it.

Good luck (hate those *#%@ things)
 
I've seen 2 big problems with the wax rubbings:
#1 is that the act of rubbing sometimes stretches the paper - in cetrain areas only- ie: the length of the piece under the wax may be longer than the paper all around it. Lay it on a flat surface and put a big piece of glass on it so your customer can see that it is not flat to begin with.
#2 is that the wax seals the paper somewhat against moisture absorbtion from humidity whereas the bare paper will usually swell and contract with changes in humidity.

These things are doomed from the start against ever being mounted nicely.
Once upon a time to save a terribly stretched out "Decorative" piece done on black craft, I trimmed it near the edge, mounted it just to ColorMount tissue (170°F) between two sheets of release paper, then re-trimmed it nicely and mounted it to black mat board. Saved the day!
 
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