Pecap as a substitute for Dacron linings

A colleague recently contacted me, after searching the DistList
archives, asking whether we had found a substitute for Dacron in
linings.  We have. I decided to share my observations with the list.

We finally discovered and ordered Pe-Cap from Talas

    <URL:http://apps.webcreate.com/ecom/catalog/product_specific.cfm?ClientID=15&ProductID=18094>

We ordered the 7-255 T (item #TCS047261).  We've used it many times
now for linings, and have been very satisfied with it.  We
particularly use it on large and huge documents, ranging from 2 feet
x 3 feet to one that was about 5 feet x 7 feet.

Here are our observations:

Like Dacron, Pecap can be washed and reused over and over. However,
you must take care not to introduce any wrinkles/creases in it.  We
used to wash our Dacron carefully in a bucket, squeezing it in the
process.  We can't do that with Pecap. Wrinkles and creases must be
avoided with PeCap.  We have to wash it flat and avoid wrinkles.

Be sure to store Pecap rolled and without any creases (just as with
Gore-Tex).  In our early experience, we rolled it and didn't notice
there was a small crease.  We've never been able to eliminate that
crease.  Fortunately, it's along the edge of one corner, so we just
avoid using that section.

Pecap is thinner than Dacron, and doesn't seem to need as much
paste.  Therefore, objects seem to dry considerably faster than with
Dacron.

In our process, we use a large piece of Plexiglas as the base, a
layer of paste onto which we place the Pe-Cap, then a layer of paste
onto which we place the Japanese paper backing, then a layer of
paste onto which we place the document.  With Dacron, we kept a
sanded sheet of Plexiglas to give it a little bit of "tooth" or
roughness to ensure the Dacron would adhere firmly. We've found that
a rougher, more coarse sanding is required with Pecap, probably
because Pe-Cap is lighter and smoother.

By the way, one other tip we discovered while we still had and used
Dacron, and it seems to be true with Pecap.  We were lining one of
those enormous survey maps and left it to dry over the weekend.  It
did not behave well.  We finally figured out the problem.  It was
winter (with the attendant low humidity here), and one end of the
table was right under the HVAC output vent.  Therefore, that end
dried much faster than the other, resulting in some bizarre behavior
of the paper.  Now we move the table to an area of the lab that
doesn't get direct air flow, and that problem has not recurred.

Hope this helps,

Lisa L. Fox
Senior Conservator Local Records Preservation Program/MSA
Office of the Secretary of State
600 W. Main
Jefferson City, MO 65101


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                  Conservation DistList Instance 28:10
                  Distributed: Sunday, August 10, 2014
                       Message Id: cdl-28-10-002
                                  ***