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How to joint compound over a wood surface to make flat with adjacent drywall?

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RobertMacy

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Jan 5, 2014, 2:34:48 PM1/5/14
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There is 1/2 inch chip board adjacent [flush surface] to drywall and need
to blend between the two with a flat surface.

*IF* instead of wood the surface were drywall; I would just tape and apply
joint compound and skim coat until flat. But, this is between drywall and
1/2 inch thick wood. So, the question is "What is the BEST way to do
this?" Should the wood be sealed [painted], or is it alright to simply
'use' the bare wood as if it were drywall?

Bob F

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Jan 5, 2014, 3:12:52 PM1/5/14
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I would run the drywall up to about 1/8"-1/4" of the wood, then use a paintable
caulk to bridge the gap. Otherwise, you will always have a crack at the edge.


dadiOH

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Jan 5, 2014, 3:15:02 PM1/5/14
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"RobertMacy" <robert...@gmail.com> wrote in message
news:op.w88bcatm2cx0wh@ajm
No idea which is best - I've done it both ways - but I'd probably put on a
coat of primer.

--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net


hrho...@sbcglobal.net

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Jan 5, 2014, 3:27:27 PM1/5/14
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On Sunday, January 5, 2014 1:34:48 PM UTC-6, Robert Macy wrote:
> There is 1/2 inch chip board adjacent [flush surface] to drywall and need to blend between the two with a flat surface. *IF* instead of wood the surface were drywall; I would just tape and apply joint compound and skim coat until flat. But, this is between drywall and 1/2 inch thick wood. So, the question is "What is the BEST way to do this?" Should the wood be sealed [painted], or is it alright to simply 'use' the bare wood as if it were drywall?

I would add sojme wood glue to the joint compound to help it adhere to the wood. But, I would bet my pension that over time there will be a crack somewhere in the vicinity of the junction unless you use something flexible somewhere at the joint. Wood just expands and contracts too much to avoid some evidence of the dissimilarity of the two materials.

Red Green

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Jan 5, 2014, 3:36:08 PM1/5/14
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RobertMacy <robert...@gmail.com> wrote in
news:op.w88bcatm2cx0wh@ajm:
Would tear away beads be helpful?

http://www.trim-tex.com/tips/TearAway.pdf

http://trim-tex.com/product_catalog.php?cat_display=showproduct&id=153

nestork

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Jan 5, 2014, 5:31:52 PM1/5/14
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Robert:

Is it feasible to replace that chip board with 1/2 inch drywall?

Because of the swelling and shrinking of the wood with changes in it's
moisture content, you're always going to get a hairline crack opening up
over the joint between the two materials.

However, if I were to do this, I'd:

1. Apply self adhesive fiberglass mesh drywall joint tape to the joint
between the drywall and the chip board.

2. Dilute some white wood glue to a paintable consistancy and paint the
chipboard with that diluted glue. Also paint the fiberglass mesh tape
on both sides of the joint. As the glue dries, it'll help bond the
fiberglass mesh tape to both the chip board and the drywall. There's no
problem letting the glue dry because white wood glue re-emulsifies when
it gets wet, so the wet drywall joint compound you put on the dried glue
will reactivate the glue and it'll help bond the joint compound to the
chipboard.

3. I would use a "curved trowel" to apply joint compound over the tape.
A curved trowel looks like an ordinary plastering trowel until you set
it down on a flat surface or sight along it's edge and notice that it
arches upward in the middle about 1/8 of an inch.

':: WALLBOARD Trim & Tool :: Curved Blade Drywall Trowel'
(http://tinyurl.com/lhkbwrk)

Because you hold the trowel at a confortable angle to the wall when
using it, a curved trowel allows you to spread a perfectly symmetric
"mound" of drywall joint compound over the fiberglass mesh tape that's
only about 5/64ths inches thick in the middle. That's too thin to show
as a "bump" on the wall, but it's plenty thick enough to cover
fiberglass mesh tape.

The curved trowel will make it easier to deal with the chipboard and
drywall not being perfectly flush at the joint as well. That's because
it's only the corners of the curved trowel that contact the wall, so
things don't have to be flush in between. If the chipboard is wider
than a few inches, I'd just use a regular trowel everywhere except over
the joint.

4. Sand smooth while holding a bright light close to the wall. The
sharp angle at which the light hits the wall exagerates the roughness of
the joint compound making it easy to see bumps that need to be sanded
down and dips that need to be filled in with more joint compound.

5. Prime and paint.




--
nestork

hrho...@sbcglobal.net

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Jan 5, 2014, 9:01:48 PM1/5/14
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What Nestork says sounds great!

Bob(but not THAT Bob)

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Jan 6, 2014, 4:03:23 AM1/6/14
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I tore out a remodeling job from the '80s and found exactly that -
drywall taped to plywood and skimmed - never would have guessed it
wasn't continuous drywall.

RobertMacy

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Jan 6, 2014, 10:35:49 AM1/6/14
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On Sun, 05 Jan 2014 15:31:52 -0700, nestork
<nestork...@diybanter.com> wrote:

>
> Robert:
>
> Is it feasible to replace that chip board with 1/2 inch drywall?
>
> ...sadly had to snip an excellent step-by-step set of instructions to
> keep Aioe happy.

Not feasible. The chip board 'fills' in a triangular area about 1 ft by 4
ft long which has almost NO support behind it. Luckily the skim coat over
the adjacent drywall is over 1/16 thick. Too late to put in 1/4 inch board
with 1/4 drywall [if exist] on top.

Any suggestion as to which glue?

RobertMacy

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Jan 6, 2014, 10:38:33 AM1/6/14
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Corner, or flat wall?

Since the chipboard is nailed adjacent to the drywall AND the minimally
attached further in, I assmed the shrinkage will be held a bit at the stud
and there won't be much possibility of cracking.

Caulki...@work.com

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Jan 6, 2014, 10:41:54 AM1/6/14
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On Mon, 06 Jan 2014 04:03:23 -0500, "Bob(but not THAT Bob)"
<nob...@nowhere.com> wrote:

>
>I tore out a remodeling job from the '80s and found exactly that -
>drywall taped to plywood and skimmed - never would have guessed it
>wasn't continuous drywall.

I got a used trailer house that has some painted walls. I thought they
were sheetrock. but after looking closer, they are the original paneling
that came with the trailer, but someone filled all the paneling grooves,
with joint compound. To me, that sure seems like a lot of work. After
moving the trailer, every actual joint cracked, but the grooves held up
fine. Since this is just gonna be a guest house,and place for storage,
i'm just gonna put some sort of trim over the joints and repaint.
Trailer houses tend to move since they are not on a foundation, so
sheetrock joints would probably crack too, and new paneling is beyond
the budget.

Norminn

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Jan 6, 2014, 11:30:13 AM1/6/14
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Chip board is very vulnerable to moisture, so I'd be sure to seal it
thoroughly. I'd put some fine-weave canvas on it, sealed with same
(spray?) sealer....then glue up the canvas with thinned Elmer's Glue.
Never done it to a wall, but have put canvas and linen on plywood for
oil painting. I'd have a roller handy to smoothe the fabric, and be
careful not to let it soak long or stretch it while applying it. All
kinds of primer coats have been used on linen/canvas, including hide
glue or gesso (plaster base). Let us know :o)

TomR

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Jan 6, 2014, 11:34:50 AM1/6/14
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> minimally attached further in, I assumed the shrinkage will be held a
> bit at the stud and there won't be much possibility of cracking.

Since you wrote earlier that the chipboard is only about a 1-foot by 4-foot
triangular piece, with minimal support behind it, I think you could still
remove the chipboard and replace it with a piece of drywall. When you put
the replacement drywall piece in, you should be able to secure it to the one
existing stud where the chipboard is now attached; and also attach it around
the perimeter of the triangle by screwing in some would strips or braces
behind the existing drywall and behind the new piece. The point is that
there is always a way to secure the new piece of drywall in place for a
section that is that small of an area.

Then use some patching plaster or a hard "setting-type" joint compound
similar to this
http://www.acehardware.com/product/index.jsp?productId=30786936&KPID=1126704&pla=pla_1126704
to fill in the perimeter gaps. Then finish like any other drywall by taping
etc.

I think that, in general, leaving the chipboard there is only going to cause
a problem down the road as the chipboard expands and contracts and/or
absorbs moisture.

Also, a couple of photos might help. You could use http://tinypic.com to do
the photo upload.


nestork

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Jan 6, 2014, 9:11:10 PM1/6/14
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RobertMacy;3177875 Wrote:
> Any suggestion as to which glue?

Any white wood glue will work for you. They can all be thinned to a
paintable consistancy if you mix water into them.

Personally, I normally buy Weldbond, but that's not because I think it's
better than other white wood glues. I've just never been sufficiently
disappointed with Weldbond to have shopped around for a better white
wood glue.




--
nestork

RobertMacy

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Jan 16, 2014, 11:16:02 AM1/16/14
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On Mon, 06 Jan 2014 09:30:13 -0700, Norminn <nor...@earthlink.net> wrote:

>> ...snip....
> Chip board is very vulnerable to moisture, so I'd be sure to seal it
> thoroughly. I'd put some fine-weave canvas on it, sealed with same
> (spray?) sealer....then glue up the canvas with thinned Elmer's Glue.
> Never done it to a wall, but have put canvas and linen on plywood for
> oil painting. I'd have a roller handy to smoothe the fabric, and be
> careful not to let it soak long or stretch it while applying it. All
> kinds of primer coats have been used on linen/canvas, including hide
> glue or gesso (plaster base). Let us know :o)

Thanksto all who responded and this idea I really like with the canvas.

I put up plywood on one side and chip on the other.

Then two very thick coats of our interior/exterior house paint [had it
lying around] to seal.

The plywood gave NO problems whatsoever. Skim coated, flat perfect.

However,...the chip board has little lcations here and there [in spite of
thick sealing coat] that raise up from the joint compound. Between the
two, I'd rate plywood ok and chip board close to disaster. I'm going to
have to do a lot in that area to fix.

RobertMacy

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Jan 16, 2014, 11:31:25 AM1/16/14
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On Mon, 06 Jan 2014 09:34:50 -0700, TomR <To...@tomrljp5.lhd> wrote:

>> ...snip....
Sadly, I agree with your dire predictions of future problems, sigh.

Didn't know about 'hard setting' plaster. just seems fraught with peril,
so to speak.

Have not been able to use any method so far of uploading pics to those
websites. I go there and the website does nothing, just sits, saying
finished and there's no way to upload, no way to register, nothing. Often
I can't even get people's posted pics downloaded either. I go to the
posted URL and the website sits there with NO indication of any 'next
step'. Sometimes works, sometimes doesn't, but usually hangs this system.
and I have to reboot - if I'm lucky, sometimes the hang is so bad I have
to power off. Then it's a bit of a wait to be back up again. And I've lost
things in 'process'

To envision, this is a rework of a fireplace. Ceilings 10 ft mantle 6 ft.
From mantle up used to go straight to ceiling, Now matches the Tuscany
style of the home with sloping top. The front is around 10 degrees sides a
bit more. So the repair work on the wall is over the small triangles on
each side of the 'stack' Luckily these are interior walls with NO
insulation or filling, but surprised me, never noticed, One wall is stud
thickness, the other wall is two stud thicknesses! A lot of wasted space
as the wall runs about 10 feet to the bathroom doorway.

Just got done last night. Very happy about using an ABS plastic drain pipe
buried in the stack and down to the electronic shelf. Cabling just inserts
and self guides down and completely out of sight with the TV mounted up
there. Like floating.

Norminn

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Jan 16, 2014, 11:37:21 AM1/16/14
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Noooooooooo.....by sealer on the chipboard, I meant non-water based.
Water base paint, I expect, would raise grain and/or loosen the glue.
Chipboard+water=sawdust.....moisture softens the glue too much.

Are your results the final product or test pieces?


Frank

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Jan 16, 2014, 1:19:18 PM1/16/14
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Like your advice but not sure glue is needed.
I like to use mesh tape where stresses and continued cracking might
develop like in the corner of a door frame.

RobertMacy

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Jan 17, 2014, 9:17:10 AM1/17/14
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On Thu, 16 Jan 2014 09:37:21 -0700, Norminn <nor...@earthlink.net> wrote:

>> ...snip...have to keep Aioe happy
> Noooooooooo.....by sealer on the chipboard, I meant non-water based.
> Water base paint, I expect, would raise grain and/or loosen the glue.
> Chipboard+water=sawdust.....moisture softens the glue too much.
>
> Are your results the final product or test pieces?

ARRRGGG! I have a can of Zinsser(sp?) forgot I had it.

This is the final. Where a patch has come up [about 1 inch diameter] 3
times now, I finally dug down, rounded the 'hole' and put Tub 'n' Tile
over the spot. That'll work.
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