Thanks for the input Mike. I don't have a humidity problem where I am
now... Just a dry heat. I think another poster may have found the problem,
and that is since I store the finishes indoors (cool) and I apply them to a
work piece in the garage (hot) I'm getting condensation and muddying
everything up. I've got a test piece cooling down indoors, and I'll do a
quick application of Danish oil before going to sleep tonight.
I think I would find a better varnish unless you may be exagerating about
having to wait for below 65% humidity. I live in Houston TX where the
humidity is rarely below 80% and I don't have those problems. Granted dry
time tends to be a bit longer but it certainly does not prohibit applying a
varnish of any kind.
Water does not have much effect on the finish when used on scraps and does
not have much effect if you are using a water based varnish.
The more moisture the has wood absorbed the more likely the Seal you use
will fail.. It may not fail ASAP on a piece of scrap wood, but it will fail.
Failure is caused when the water that is placed on the wood eventually finds
an exit. This will cause the surface of the wood where the water was applied
to shrink whick causes tiny fractures in the Finished Surface and will lead
to a costly re-finishing job..
I am sure you've seen these fractures on a finished surface.. The same will
happen if you use wood with high moisture content. But eventually the finish
will chip or floof off the surface of the wood turning your finish into
dust. This is why I suggest that if you wish to see how the wood will appear
before you add the Finish Sealer, use Mineral Spirits.
I've tried the water base Polyurethane once and was not impressed and went
back to the Oil Base Finishs.. They last much longer.
IMO your water comments need to be qualified a bit. Nearly all wood has some
water in it, and the amount slowly changes during the year. Finishes slow down
but do not stop the exchange. Look at design aspects that take into account
wood movement. Also include the common technique of spraying with water to
raise the grain before finishing. What you're describing take an awful lot
more water to cause those issues. As you mention, the wood moisture content is
your best guide.
Christ is in our Midst!
God Bless Gerry,
The next time you spray water to make the grain raise, do not spray the ends
of the wood.. Only spray the surface and look at the ends how deep the water
has penetrated the wood.. I've seen ARC absorb a light spray of water on the
surface of a piece as much as a 1/4" and that was only what I could see..
I've seen Black Walnut and Red Oak absorb a light spray of water as much as
1/8" to a 1/4" into the wood.. The more porous the wood the deeper you can
see a fine mist go into the wood. And if you can see where the moisture has
gone 1/4" into the wood, you can add another 1/16" to an 1/8" to the most
porous places on the surface you just sprayed that you can not see.. Now
after you wipe the water from the surface of the piece and apply your
varnish, that water is trapped under the surface of the wood and when it
finds a place in your finish to evaporate, and it will, the wood will shrink
under the finish causing what I call "Microcracks" to form in the finish
which will allow the wood to breath better and absorb the moisture it lost..
The process of evaporating, microcracking will continue until the
microcracks will weaken the bond between the varnish and the fibers of the
wood allowing the varnish to chip or fluff off until you have a re-finishing
job and a PO'ed customer wanting you to refinish the piece.. I have seen
this MicroCracking occur on pieces within 2 years. Which is why I always use
Paint Thinner (Mineral Spirits) to raise the grain of a piece I am getting
ready to finish.. The added oils in the mineral spirits tends to help the
finish by resisting humidity and curves the need for raising the grain with
water that is absorbed by the wood..
Please forgive me, sometimes I will comment on something assuming it is a
well known concept and feel no need to go into great detail.. I will try and
mend my ways on future comments.
I think we'll have to just disagree on the degree here. Jewitt and other
finishers don't seem concerned, and I haven't seen an issue from this in
several decades of working with wood.
Now, you spoke about "added oils" in mineral spirits? Do you mean if I let
some dry on a piece of clean glass, I'll then see an oil residue? I don't
Mineral Spirits or as sold by EXXON as VARSOL is an oil base product and
definitely will leave an oil residue as will most oil base paint thinners.
Laquor thinner, MEK, and others will leave a powdery ash which is less
Lest we forget, the first rule states:
No single rule will always apply.
Many people have seen different problems and issues, and some have solutions,
but may not realize that both the problems and solutions are often dependent
on a bunch of detail that may not be obvious. That unless you can repeat them
under many other conditions, you do not have a general rule. Add to this the
"...in the eye of the beholder", and arguments often end up with more
personalities than facts.
Michael, I don't doubt what you've seen, but suggest there are other factors
involved and this is not an often seen issue.
Christ is in our Midst!
Look Leon, you said your were having a problem with your finish I assumed
you were asking for advice.. I gave you advice based on my experience and
instead of thanking me for my efforts or simply not heeding the advice and
letting it go at that you have created an entire thread and seem to be more
interested discounting the information I have given you which I have learned
over the years via experience.. I thought I left the ingrates in REC, but
apparently a couple went over the fence. So here are two last bits of advice
I will give you.. This ain't REC.. If you want to argue, go there and argue
all you want.. I left REC for this very reason and came here.. And the last
bit of advice, don't hold your breath until you get anymore help from me!
Just got no time for arguing over things I know to be true.. Got no need to
convince you of anything. After all you're a big boy, figure it out
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