On 10/26/2014 12:51 PM, Leon wrote:
On 10/25/2014 2:38 PM, wrote:
Thanks, John. I'll definitely look into shellac.

Update: the finish seems fine until I run fingers over it. There is a
slight oily residue that comes off on my fingers. This hasn't gone
away after a week. Is this normal for poly??



Not normal. Is that "new" can of finish?

I find myself especially curious about this so I'd like to recap.

Its seems we have several factors here, and two questions. The first
question: what accounts for this strange result?

Here are (some of the) possibilities:

1. The state of the can of finish.

Do these have date codes? I have seen some pretty un-saleable things
returned to the shelves of Home Depot. What happens to old poly?

2. Insufficient stirring.

The instructions say to mix thoroughly before - and even during -
application. But what happens if we don't? Is it simply that we will
have a more dilute mixture near the top of the can? If so it's hard to
imagine that causing the reported symptom. After all, some of us have
thinned poly on purpose without that result. Or maybe something else
separates out as well?

3. The temperature.

If I remember correctly, poly "dries" by two processes. First the
solvent evaporates, then the "polymerization" reaction occurs over time.
If memory serves, the second reaction at least (the "curing") is
retarded by lower temperatures. But the piece was eventually brought
into a heated space. Would it then cure properly, even if the process
had been slowed by the lower temperature?

4.The timing.

The online instructions say to wait 4-6 hours between coats. So again,
what happens if we don't wait long enough, "long enough" perhaps being
lengthened by the ambient temperature during the first hour outside?
Does the second coat prevent enough oxygen from getting to the first
coat, perhaps?

5. The radiator heat.

But of course, all of the above is to some degree an academic exercise,
with the possible exception of the condition of the can of finish. What
does Tim do now to fix it?

I'm guessing he finished the inside surfaces of the project as well. So
perhaps the first bit of advice would be to try out a repair strategy on
the inside surfaces. If successful, repeat on the surfaces that will show.

Finishing figures prominently among the topics I'm ignorant about, but
if this were my own project I'd be inclined to try removing the oily
residue with a solvent like mineral spirits. If that seemed successful,
I'd probably scuff the finish a little and reapply poly - from a
different can - just to be safe. I'd stir, and watch the temperature,
and wait a whole day before considering any further coats.

One other thing:

Perhaps, given the apartment setting and his infant son, a water-borne
poly would have been a good choice. I thought I read somewhere that
despite being *carried* by water, the poly is still poly. Does this mean
that he could try water-borne poly over what he's got (with some surface
prep, but without sanding down to bare wood)? Or is there perhaps some
other choice that's sufficiently non-hazardous to do entirely inside his
heated apartment?

Sorry for the long-winded questions (my specialty), but I have taken a
special interest in this young man's predicament for some reason.



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