I just looked a several mitered joints (picture frame type) that I did a
four to six months ago and noticed that they have all opened up on the
outside.
The stock is variously 1 x 2.5 to 1 x 4 oiled and stained birch. The
lengths of the sides are variously 12 to 60 inches. The four corners
were cut at 45 degrees using an Incra 1000 miter gauge and appeared to
be perfect when done.
The inside corners (the short edge) are all tight. The outside corners
(3 to 5.5 inches away) have all opened up by about 1/32 to 1/16" Not
too much, but enough to be noticeable. All joints were made with
biscuits and Titebond II.
I've had the wood in the house for about 8 years. However, I do see
significant humidity changes as I am 75 feet from the high water mark
(Atlantic Ocean.)
Any thoughts as to why there seems to be non-uniform movement? And more
importantly, how to prevent it?
Phil
Mike, I'm not sure what books and videos you have, but wood always crowns
toward the heart. This may or may not be because the outer rings have more
"tension," but heartwood is definitely more dense, in proportion, with
harder latewood.
Note that an unprotected log is not compressed by the greater "tension" of
the outer annual rings, rather splits radially.
"Mike" <[email protected]> wrote in message
news:[email protected]...
> PC,
>
> I wonder if this is related to the grain direction of the wood. I.e.
> the rings on the tree.
SNIP
> It would be interesting to know how the grain looks on your wood. The
> outer rings have the most tension (since they "wrap" around the wood a
> longer distance -- think rubber band pulled tight vs not pulled
> tight). If the outer rings are facing outside your frame that might
> be the problem.
>
> (newbie with book/video smarts, but not a lot of experience
> smarts...good luck ;)
It is.
"Gregg Germain" <[email protected]> wrote in message
news:[email protected]...
> George <[email protected]> wrote:
> : Cup IS the opposite of crown, isn't it?
>
> Is it? I was not under that impression.
>
>
> --- Gregg
> "Improvise, adapt, overcome."
> [email protected]
> Smithsonian Center for Astrophysics
> Phone: (617) 496-1558
>
Not on your life. Living on the ocean is the best thing that you can
imagine. It sure beats the *#%* of Dallas!
Phil
Bob S. wrote:
>>Any thoughts as to why there seems to be non-uniform movement?
>
>
> The outside miters are closer to the ocean than the inside ones ?
>
>
>>And more importantly, how to prevent it?
>
>
> Move further away from the ocean until the joints reach a point of
> equilibrium....
>
> ;)
>
>
George <[email protected]> wrote:
: Mike, I'm not sure what books and videos you have, but wood always crowns
: toward the heart. This may or may not be because the outer rings have more
: "tension," but heartwood is definitely more dense, in proportion, with
: harder latewood.
That has not been my experience. My experience is that the wood cups
away from the center of the log. The outer rings try to flatten
themselves.
--- Gregg
My woodworking projects:
Replicas of 15th-19th century nautical navigational instruments:
http://home.attbi.com/~saville/backstaffhome.html
Restoration of my 82 year old Herreshoff S-Boat sailboat:
http://home.attbi.com/~saville/SBOATrestore.htm
Steambending FAQ with photos:
http://home.attbi.com/~saville/Steambend.htm
"Improvise, adapt, overcome."
[email protected]
Smithsonian Center for Astrophysics
Phone: (617) 496-1558
George <[email protected]> wrote:
: Cup IS the opposite of crown, isn't it?
Is it? I was not under that impression.
--- Gregg
"Improvise, adapt, overcome."
[email protected]
Smithsonian Center for Astrophysics
Phone: (617) 496-1558
um now that you mention it yeah!
--
Young Carpenter
"Save a Tree, Build Furniture"
"George" <[email protected]> wrote in message
news:[email protected]...
> Cup IS the opposite of crown, isn't it?
>
> "Gregg Germain" <[email protected]> wrote in message
> news:[email protected]...
> > George <[email protected]> wrote:
> > : Mike, I'm not sure what books and videos you have, but wood always
> crowns
> > : toward the heart. This may or may not be because the outer rings have
> more
> > : "tension," but heartwood is definitely more dense, in proportion, with
> > : harder latewood.
> >
> > That has not been my experience. My experience is that the wood cups
> > away from the center of the log. The outer rings try to flatten
> > themselves.
> >
> > --- Gregg
> >
> > My woodworking projects:
> >
> >
> > Replicas of 15th-19th century nautical navigational instruments:
> >
> > http://home.attbi.com/~saville/backstaffhome.html
> >
> > Restoration of my 82 year old Herreshoff S-Boat sailboat:
> >
> > http://home.attbi.com/~saville/SBOATrestore.htm
> >
> > Steambending FAQ with photos:
> >
> > http://home.attbi.com/~saville/Steambend.htm
> >
> >
> > "Improvise, adapt, overcome."
> > [email protected]
> > Smithsonian Center for Astrophysics
> > Phone: (617) 496-1558
> >
>
>
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
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You said they were oiled and stained but never mentioned any finish over
that. Oil only minorly retards the loss of moisture, stain even less.
"Understanding wood Finishes" Indicates that a thin sealer coat of a
material such as Shellac will help even out moisture loss.
--
Young Carpenter
"Save a Tree, Build Furniture"
"PC" <[email protected]> wrote in message
news:[email protected]...
> I just looked a several mitered joints (picture frame type) that I did a
> four to six months ago and noticed that they have all opened up on the
> outside.
>
> The stock is variously 1 x 2.5 to 1 x 4 oiled and stained birch. The
> lengths of the sides are variously 12 to 60 inches. The four corners
> were cut at 45 degrees using an Incra 1000 miter gauge and appeared to
> be perfect when done.
>
> The inside corners (the short edge) are all tight. The outside corners
> (3 to 5.5 inches away) have all opened up by about 1/32 to 1/16" Not
> too much, but enough to be noticeable. All joints were made with
> biscuits and Titebond II.
>
> I've had the wood in the house for about 8 years. However, I do see
> significant humidity changes as I am 75 feet from the high water mark
> (Atlantic Ocean.)
>
> Any thoughts as to why there seems to be non-uniform movement? And more
> importantly, how to prevent it?
>
> Phil
>
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----
PC,
I wonder if this is related to the grain direction of the wood. I.e.
the rings on the tree. I was watching Frank Klausz the other day
(dovetail joints) and he mentioned being aware of what direction you
put the rings when building drawers because the corners can cup away
from the inside of the drawer out and then not fit in the drawer slot
anymore. Thus you flip the wood around so the expansion would be
forced toward the box and against the joints (and I assume not really
move much??).
It would be interesting to know how the grain looks on your wood. The
outer rings have the most tension (since they "wrap" around the wood a
longer distance -- think rubber band pulled tight vs not pulled
tight). If the outer rings are facing outside your frame that might
be the problem.
(newbie with book/video smarts, but not a lot of experience
smarts...good luck ;)
Mike
[snip]
> The inside corners (the short edge) are all tight. The outside corners
> (3 to 5.5 inches away) have all opened up by about 1/32 to 1/16" Not
> too much, but enough to be noticeable. All joints were made with
> biscuits and Titebond II.
[snip]
> noticed that they have all opened up on the
> outside.
The wood has expanded across its width, opening the joints. If you
could measure the width of the frame pieces back when you made them, it
would be a bit narrower than it is now.
> appeared to
> be perfect when done.
They WERE perfect when done. That was then. ;)
> I've had the wood in the house for about 8 years. However, I do see
> significant humidity changes as I am 75 feet from the high water mark
> (Atlantic Ocean.)
Overall humidity changes, i.e. summer vs. winter, are the culprit.
Wait six months, and they will have closed up again or even opened on the
inside.
> Any thoughts as to why there seems to be non-uniform movement? And more
> importantly, how to prevent it?
Wood swells and shrinks most along the yearly growth rings.
Consequently, flatsawn wood has much greater movement than quartersawn.
Planning for wood movement is one of the most difficult lessons I've had to
learn. I'd recommend reading Bruce Hoadley's book "Understanding Wood" for
the most complete analysis of the subject.
Cup IS the opposite of crown, isn't it?
"Gregg Germain" <[email protected]> wrote in message
news:[email protected]...
> George <[email protected]> wrote:
> : Mike, I'm not sure what books and videos you have, but wood always
crowns
> : toward the heart. This may or may not be because the outer rings have
more
> : "tension," but heartwood is definitely more dense, in proportion, with
> : harder latewood.
>
> That has not been my experience. My experience is that the wood cups
> away from the center of the log. The outer rings try to flatten
> themselves.
>
> --- Gregg
>
> My woodworking projects:
>
>
> Replicas of 15th-19th century nautical navigational instruments:
>
> http://home.attbi.com/~saville/backstaffhome.html
>
> Restoration of my 82 year old Herreshoff S-Boat sailboat:
>
> http://home.attbi.com/~saville/SBOATrestore.htm
>
> Steambending FAQ with photos:
>
> http://home.attbi.com/~saville/Steambend.htm
>
>
> "Improvise, adapt, overcome."
> [email protected]
> Smithsonian Center for Astrophysics
> Phone: (617) 496-1558
>