Answering several posts in one ...
Many of the 'flexible adhesives' ... such as Walther's Goo ... will out gas
fumes for -years- after they appear to be set/cured. I've had a box car
'melt' from such emissions as long as 7 years after Goo was used to attach
a weight. When that happened I swore off Goo and anything that seemed
similar and haven't looked back. I have used Gorilla Glue (which is a
different adhesive from white glue or Goo) on occasion but I'm not sure I'd
use it "in a closed space" such as a plastic box car or locomotive or caboose.
By "Elmer's/White Glue" I'm referring to that product and to Krystal
Klear and to other such "milk protein based adhesives". Carpenter's
glue (Elmer's or other) is yellow and is also made from milk ... but
will -not- soften due to water after it has cured/set (at least not enough
My most common "white glue" is KK.
I have not had any problem with KK or Elmer's 'letting go' of any car
weight. I smear some of the KK on the car floor (usually inside a
box/reefer) or 'on the underside of a flat car ... put in some weight
(often lead shot or sheet lead) and add more KK after to form a filet
along the edges. Or actually covering up over the edges to the top
of the weight such as when using sheet lead.
I -always- "set the car aside for 4 to 24 hours" before doing
anything else to it. If the KK/white glue isn't -totally- clear I
leave it alone. Room temperature and air movement can
affect the drying/curing time. Even 24 hours can be "not enough"
- YMMV ... Jim
P.S. Tony, I have used Canopy Cement back when I was flying R/C. I
think it is very likely "a form of white glue". Just like KK. KK has
some stuff added to it to make it the consistency it is - and
perhaps to also make it dry clearer or easier to span an opening.
P.P.S. I rarely use KK for its intended purpose 9windows). But it is one
of my go to adhesives.