Pine oozing sap after poly
Barry Hausmann
so I'm turning to the newsgroup for help. He bought an unfinished
entertainment center made from pine. He applied stain, and then 3 coats
of Behr water-based poly. After applying the poly he found that the doors
expanded and then rebounded to their normal size. While this is
explainable since the wood will still move after being poly'd, his other
problem I had more difficulty with. There is sap oozing from the pine on
one of the doors. It hasn't broken through the poly, but is making a
buuble in the small area where it is happening. How can this be fixed?
And how is this making the poly bubble in that spot? Luckily
it's only one board on one door so far, so it's not the end of the world.
I thank you, and he thanks you too. I'll forward the responses to him.
- Barry
--
Barry Hausmann, Raytheon Co., Electronic Systems Division
Software Engineering Lab
(Work) Haus...@ed.ray.com (Home) BEHau...@aol.com
My opinions are my own... who else would want them?
NO THANKS -- I'M ON SABBATICAL.
Youch!
If the wood is oozing sap, that means it hadn't seasoned
nearly enough before being turned into furniture. If the ooze
is pushing the polyurethane off, it may be that there was
some pitch on the wood surface when the finish was applied, preventing
a proper bond to the wood, and inviting a bubble to form.
To get the wood to season properly, your friend should,
most probably, remove the finish entirely. Now the bad news:
polyurethane can't be gotten off by any method besides sanding (as far
as I know; there might be a heavy-duty stripper out there that
would take it off, but I haven't seen one). To sand a whole
entertainment center down doesn't seem like a lot of fun, and
if the rest of the finish is doing okay, it might not be necessary. He
could try just this one spot, and hope nothing else happens. Sand, wait
a long time (until there's no more sap), wait some more, apply
more finish.
If he does completely remove all the finish from the whole thing,
he might consider the alternative finishes (shellac, oil, oil/varnish,
etc). They're easier to repair.
des
There is a fairly short period of time (a few days) within
hau...@mbi.org
>From: haus...@news.ed.ray.com (Barry Hausmann)
>Subject: Pine oozing sap after poly
>Date: 11 Sep 1995 16:27:50 GMT
> He bought an unfinished
>entertainment center made from pine. He applied stain, and then 3 coats
>of Behr water-based poly. After applying the poly he found that the doors
>expanded and then rebounded to their normal size. While this is
>explainable since the wood will still move after being poly'd, his other
>problem I had more difficulty with. There is sap oozing from the pine on
>one of the doors. It hasn't broken through the poly, but is making a
>buuble in the small area where it is happening.
Pine does this. It's one reason most of us don't use it for fine furniture.
Being commercial furniture, the wood probably wasn't dried properly, which
makes the sap problem worse.
How can this be fixed?
Other than waiting a while and trying to refinish that spot (which would be
hard with PU), I don't know. Live and learn.
Rich
Mark Kepke
You can use shellac to seal knots or use an oil finish (easy to touch-up)
on new furniture. Stripping the piece is possibly the only solution in
your friend's case.
I know of woodwork in century homes that still 'leaks'.
--
-Mark
My opinions, etc.
Paul Bruning
>
There is sap oozing from the pine on
>
Try placing the pine (unfinished) into a klin. Given enough heat the sap
will crystalize and not run.
John Thomas Riley
>And how is this making the poly bubble in that spot? Luckily
>it's only one board on one door so far, so it's not the end of the world.
You probably have a resin vain. This is will show as a thin dark
line. The tree was once injured and fill the scar with sap. It then
healed over the trapped sap. The traped pitch is now working its way
out and will continue to do so for a long time.
You could try cutting deep into the wood with good carving chisel.
Make the cut narrow but deep, removing as much of the vain as you can.
Cut through from the back side if that helps you keep the cleff
narrow.
Now you have a hole to fill. Fill the bottom of the hole with an
absorbident material like RockHard wood putty. For the top you can
try taking two dark colors of plastic wood filler and making an
imitation knot. Place a small amount of each color on a plastic lid
and fold them together just a little. Fill the hole with this mixture.
The two colors are intended to avoid the flat unnatural uniform color
you get with only one. This may take practice.
You will then have to refinish a significant area around the repair
and you might as well refinish the whole door.
Chris Lewis
Mark Kepke <mke...@bnr.ca> wrote:
>In article <haubert.61...@mbi.org>, hau...@mbi.org wrote:
>
>> In article <431o26$i...@news.res.ray.com> haus...@news.ed.ray.com (Barry
>Hausmann) writes:
>> > He bought an unfinished
>> >entertainment center made from pine. He applied stain, and then 3 coats
>> >of Behr water-based poly. After applying the poly he found that the doors
>> >expanded and then rebounded to their normal size. While this is
>> >explainable since the wood will still move after being poly'd, his other
>> >problem I had more difficulty with. There is sap oozing from the pine on
>> >one of the doors. It hasn't broken through the poly, but is making a
>> >buuble in the small area where it is happening.
>> Pine does this. It's one reason most of us don't use it for fine furniture.
>> Being commercial furniture, the wood probably wasn't dried properly, which
>> makes the sap problem worse.
>>> How can this be fixed?
>>
>> Other than waiting a while and trying to refinish that spot (which would be
>> hard with PU), I don't know. Live and learn.
>You can use shellac to seal knots or use an oil finish (easy to touch-up)
>on new furniture. Stripping the piece is possibly the only solution in
>your friend's case.
Here's an even more effective trick than shellac alone: get out a blow dryer
or heat gun (very carefully with the latter), and heat up the knot. The pitch
will come to the surface, and you wipe it off with alcohol. Keep doing this
until no more seems to come out. Then shellac it.
The reason why pine isn't used for fine furniture is that it's soft, and
usually fairly uninteresting, not because pine sometimes leaks sap. Leaking sap
is easy to prevent. I've used quite a bit of pine, and haven't had this problem.
If Barry's friend carefully sands off the area, does what I suggest above, and
re-polys, it will probably work just fine without having to strip the whole door.
--
Chris Lewis: _Una confibula non sat est_
Latest psroff: ftp://ftp.uunet.ca/distrib/chris_lewis/psroff3.0pl17/*
Latest hp2pbm: ftp://ftp.uunet.ca/distrib/chris_lewis/hp2pbm/*
NNTP AUTHINFO GENERIC info: ftp://ftp.uunet.ca/distrib/chris_lewis/generic/*