Re: Refreshing Green Stuff
I just did some testing on some really old putty (with a skin that is
thick enough not to tear when you pull it off!). Two tests. The first
was 30 minutes in my putty oven with a 15 Watt lamp, the second 10
minutes. I put in both seperate pieces of blue and yellow.
- the putty does indeed become very soft and sticky (like ordinary
- areas that have already cured like the centre bit of a ribbon and
the skin remain hard.
- The soft putty makes it a lot easier to remove the skin from the
yellow ribbon, so salvaging putty works much better.
- both blue and yellow remain soft when warm but then go back to their
old stiffness before heating. Warming them should get them soft again.
- the only difference between the 30 min and 10 min exposure was that
the putty remained softer longer after the 30 min exposure.
I also asked Bob Finkenaur (who works as an independent advisor on
epoxy products nowadays) and this is his reply:
My guess is that the yellow in the sample was skinned but under the
skin the material had become stiffer but not hardened like the surface
skin. Heat reduces viscosity of the putty so the stiff material in
the center and possibly even the skin became softer and useable. The
skinned has already reacted with heat and moisture so will probably
not react with the blue correctly in any case. OK for bulking up as
Thanks again for trying this out. I'll copy the details and put it in
my files to add to the FAQ.