"DerbyDad03" wrote in message
...
On Monday, May 21, 2018 at 10:22:21 AM UTC-4, Leon wrote:
On 5/20/2018 11:06 PM, DerbyDad03 wrote:
I've been using this '1/8" method' to clean the brushes I use for oil
based
primer. The primer is Zinsser Cover Stain, just white, no tint.

https://www.youtube.com/watch?v=DDvDbKBTbic

I collect the used mineral spirits in a jar and let the primer settle
out
so I can recycle the mineral spirits and use it to clean the brushes
again.

I've found that instead of the mineral spirits being clear after the
primer
settles to the bottom of the jar, it is sort of an amber colored clear.
I
don't think it's a matter of not waiting long enough because I've gone
weeks
without touching the jar.

The recycled spirits seem to work just as well as new spirits for
cleaning
brushes, but I'm curious as to why it is no longer clear. What is in
the
primer that would cause the spirits to turn amber?



Do you remember chemistry class, some ingredients settle and separate
others remain mixed.


Yep, that's why I ask *what* is in the primer that turns the MS Amber. ;-)
According to
dadiOH the answer is "linseed oil".

The oil isn't the primer; it is the binder - what keeps the primer in place
on the wall after it dries.