br

brian roth

12/11/2010 5:16 PM

Veneer just one side of MDF?

I'd like to build a fireplace mantel that features veneered panels.

Unlike say a cabinet door, the other side of the panel will never be
seen.

Is it neccesary to veneer both sides? Does MDF move with moisture?


This topic has 19 replies

Rr

RonB

in reply to brian roth on 12/11/2010 5:16 PM

17/11/2010 5:24 AM

On Nov 17, 3:42=A0am, "J. Clarke" <[email protected]> wrote:
> In article <5ddf3f89-bf6d-48e0-a009-88867b7d7232
> @a37g2000yqi.googlegroups.com>, [email protected] says...
>
>
>
>
>
> > On Nov 13, 9:37=A0am, "Leon" <[email protected]> wrote:
> > > "brian roth" <[email protected]> wrote in message
>
> > > Have you thought about what the heat rising up to the mantel might to=
the
> > > veneer/glue on the mantel?
>
> > When read the original post I was thinking the same thing. =A0When I
> > built our mantel I used solid 2" Oak and placed it well above the
> > minimum height recommended by the fireplace/stove manufacturer. =A0That
> > dude still gets warm. =A0You might want to check into the durability of
> > MDF when exposed to heat in the 120 to 130 degree range. =A0I don't kno=
w
> > if it will degrade; but best to know now.
>
> I don't understand this business of mantels being exposed to heat. =A0
> Maybe I'm just old fashioned but to me a mantel is a part of a brick or
> stone fireplace and if it gets too hot for a cat to sleep on something
> is badly wrong.

A good part of the mantles being installed today are on insert
fireplaces. These are essentially gas heaters or wood-burning stoves
that have brick or tile faces surrounded by wood trim and a mantel.
Little or no masonry

For example, we installed a Buckmaster high efficiency wood stove in
our house which is essentially a souped-up insert with external
combustion air ducts, a catalytic combuster and a blower system. The
unit builds in like a fireplace with ceramic tile front surrounded by
mantel front and shelf. Buck provides specific installation
instructions and clearances and our installation clearances exceed
recommendations. The internal temperatures in these catalytic
fireplaces gets above 1000 degrees and they put out heat. Heat rises
from the face and the mantle gets warm. We had two gas fireplaces in
our previous house and the mantle above the insert face got warm. The
front of the masonry wood-burning fireplace and mantle in the older
house we lived in got warm. I cannot imagine the front of a
fireplace, that gets used, not getting warm.

I am just a little concerned that fireplace facing is the best place
to use MDF. The temperatures involved with our current installation
are in the 90 to 120 degree range. Far-far from any combustion
concerns but I was suggesting the poster should look at long term
effects of heat on his material. Some fireplaces sit unused during
much of their lives. Ours is running now and will run muchof the them
for the next 4-5 months. Will MDF or Veneered MDF hold up to this?

Also, depends on the cat. Our, now dearly departed, dog would have
loved to lay on our warm mantle if he could have hoisted his aging 105
pound butt up there. :^}

RonB

Rc

Robatoy

in reply to brian roth on 12/11/2010 5:16 PM

15/11/2010 5:03 AM

On Nov 14, 10:41=A0pm, "J. Clarke" <[email protected]> wrote:
> In article <c069efa2-f11c-4615-8ca3-b8836cf17ee3
> @i4g2000pro.googlegroups.com>, [email protected] says...
>
>
>
> > On Nov 13, 9:16=A0am, brian roth <[email protected]> wrote:
> > > I'd like to build a fireplace mantel that features veneered panels.
>
> > > Unlike say a cabinet door, the other side of the panel will never be
> > > seen.
>
> > > Is it neccesary to veneer both sides? =A0Does MDF move with moisture?
>
> > If the other side of the panel is invisible, you can choose MDF with
> > veneer just one side.
> > MDF is stable with moisture .
>
> Lay a piece on your lawn and see how it looks the next morning.

The grass gets all yellowy?

Ll

"Leon"

in reply to brian roth on 12/11/2010 5:16 PM

17/11/2010 7:34 AM


"RonB" <[email protected]> wrote in message
news:[email protected]...
On Nov 17, 3:42 am, "J. Clarke" <[email protected]> wrote:
> In article <5ddf3f89-bf6d-48e0-a009-88867b7d7232
> @a37g2000yqi.googlegroups.com>, [email protected] says...
>
>
>
>
>
> > On Nov 13, 9:37 am, "Leon" <[email protected]> wrote:
> > > "brian roth" <[email protected]> wrote in message
>
> > > Have you thought about what the heat rising up to the mantel might to
> > > the
> > > veneer/glue on the mantel?
>
> > When read the original post I was thinking the same thing. When I
> > built our mantel I used solid 2" Oak and placed it well above the
> > minimum height recommended by the fireplace/stove manufacturer. That
> > dude still gets warm. You might want to check into the durability of
> > MDF when exposed to heat in the 120 to 130 degree range. I don't know
> > if it will degrade; but best to know now.
>
> I don't understand this business of mantels being exposed to heat.
> Maybe I'm just old fashioned but to me a mantel is a part of a brick or
> stone fireplace and if it gets too hot for a cat to sleep on something
> is badly wrong.

Snip


Actually a wood fire place mantel in many states has to be built to meet
code as it is normal for them to get warm to hot and could catch on fire.
If a mantel gets hot the fire place tends to be a bit more efficient as more
of the heat is actually coming out into the room vs. going up the chimney.





LH

"Lew Hodgett"

in reply to brian roth on 12/11/2010 5:16 PM

12/11/2010 8:42 PM


"brian roth" wrote:

> I'd like to build a fireplace mantel that features veneered panels.
>
> Unlike say a cabinet door, the other side of the panel will never be
> seen.
>
> Is it neccesary to veneer both sides? Does MDF move with moisture?
----------------------------------------
It may not be necessary, but like chicken soup, maybe it has no
medicinal value but hadn't ought to hurt.

If it were my project, I'd seal the cut MDF edges with diluted glue
(TiteBond) per an earlier thread, then seal all the non veneered
surfaces with a couple of coats of 2 pound dewaxed shellac applied
with a 2" chip brush.

Quick, low cost and effective.

Lew

Rr

RonB

in reply to brian roth on 12/11/2010 5:16 PM

15/11/2010 8:06 PM

On Nov 13, 9:37=A0am, "Leon" <[email protected]> wrote:
> "brian roth" <[email protected]> wrote in message
>

>
> Have you thought about what the heat rising up to the mantel might to the
> veneer/glue on the mantel?
>

When read the original post I was thinking the same thing. When I
built our mantel I used solid 2" Oak and placed it well above the
minimum height recommended by the fireplace/stove manufacturer. That
dude still gets warm. You might want to check into the durability of
MDF when exposed to heat in the 120 to 130 degree range. I don't know
if it will degrade; but best to know now.

RonB

Hg

Hoosierpopi

in reply to brian roth on 12/11/2010 5:16 PM

18/11/2010 8:51 AM

On Nov 12, 8:16=A0pm, brian roth <[email protected]> wrote:
> I'd like to build a fireplace mantel that features veneered panels.
>
> Unlike say a cabinet door, the other side of the panel will never be
> seen.
>
> Is it neccesary to veneer both sides? =A0Does MDF move with moisture?

My experience is that: It Moves

I had a table top from Subway that I turn into a Router Table top. It
was NOT laminated on the "bottom" and had that plastic edging
installed (The type that fits in a kerf along the edges). After on
year in the basement (cold, not dry) it sagged significantly and I
knew it was my failure to seal the bottom surface with laminate or
equivalent.

For a one off project, the savings between good plywood and MDF are
not worth taking the chance IMHO considering the labor involved ....

JC

"J. Clarke"

in reply to brian roth on 12/11/2010 5:16 PM

14/11/2010 10:41 PM

In article <c069efa2-f11c-4615-8ca3-b8836cf17ee3
@i4g2000pro.googlegroups.com>, [email protected] says...
>
> On Nov 13, 9:16 am, brian roth <[email protected]> wrote:
> > I'd like to build a fireplace mantel that features veneered panels.
> >
> > Unlike say a cabinet door, the other side of the panel will never be
> > seen.
> >
> > Is it neccesary to veneer both sides?  Does MDF move with moisture?
>
> If the other side of the panel is invisible, you can choose MDF with
> veneer just one side.
> MDF is stable with moisture .

Lay a piece on your lawn and see how it looks the next morning.

JC

"J. Clarke"

in reply to brian roth on 12/11/2010 5:16 PM

17/11/2010 4:42 AM

In article <5ddf3f89-bf6d-48e0-a009-88867b7d7232
@a37g2000yqi.googlegroups.com>, [email protected] says...
>
> On Nov 13, 9:37 am, "Leon" <[email protected]> wrote:
> > "brian roth" <[email protected]> wrote in message
> >
>
> >
> > Have you thought about what the heat rising up to the mantel might to the
> > veneer/glue on the mantel?
> >
>
> When read the original post I was thinking the same thing. When I
> built our mantel I used solid 2" Oak and placed it well above the
> minimum height recommended by the fireplace/stove manufacturer. That
> dude still gets warm. You might want to check into the durability of
> MDF when exposed to heat in the 120 to 130 degree range. I don't know
> if it will degrade; but best to know now.

I don't understand this business of mantels being exposed to heat.
Maybe I'm just old fashioned but to me a mantel is a part of a brick or
stone fireplace and if it gets too hot for a cat to sleep on something
is badly wrong.

JC

"J. Clarke"

in reply to brian roth on 12/11/2010 5:16 PM

17/11/2010 10:17 AM

In article <[email protected]>, lcb11211
@swbell.dotnet says...
>
> "RonB" <[email protected]> wrote in message
> news:[email protected]...
> On Nov 17, 3:42 am, "J. Clarke" <[email protected]> wrote:
> > In article <5ddf3f89-bf6d-48e0-a009-88867b7d7232
> > @a37g2000yqi.googlegroups.com>, [email protected] says...
> >
> >
> >
> >
> >
> > > On Nov 13, 9:37 am, "Leon" <[email protected]> wrote:
> > > > "brian roth" <[email protected]> wrote in message
> >
> > > > Have you thought about what the heat rising up to the mantel might to
> > > > the
> > > > veneer/glue on the mantel?
> >
> > > When read the original post I was thinking the same thing. When I
> > > built our mantel I used solid 2" Oak and placed it well above the
> > > minimum height recommended by the fireplace/stove manufacturer. That
> > > dude still gets warm. You might want to check into the durability of
> > > MDF when exposed to heat in the 120 to 130 degree range. I don't know
> > > if it will degrade; but best to know now.
> >
> > I don't understand this business of mantels being exposed to heat.
> > Maybe I'm just old fashioned but to me a mantel is a part of a brick or
> > stone fireplace and if it gets too hot for a cat to sleep on something
> > is badly wrong.
>
> Snip
>
>
> Actually a wood fire place mantel in many states has to be built to meet
> code as it is normal for them to get warm to hot and could catch on fire.
> If a mantel gets hot the fire place tends to be a bit more efficient as more
> of the heat is actually coming out into the room vs. going up the chimney.

Everything has to be built to meet code if there is a code. I don't see
how that changes anything. I can see where it's an issue with some
modrin stove that pretends to be a fireplace, but if it's the real
firebrick-lined brick and mortar deal there's a lot of brick and mortar
between the mantel and the fire and only a slight projecting lip of wood
above.

If these things are in the wall and get that hot I'd be more worried
about the wall catching fire than the mantel.

If MDF won't take 120F then it's in trouble in Texas.


JC

"J. Clarke"

in reply to brian roth on 12/11/2010 5:16 PM

17/11/2010 10:23 AM

In article <100e92c2-de51-4ed0-b85b-
[email protected]>, [email protected] says...
>
> On Nov 17, 3:42 am, "J. Clarke" <[email protected]> wrote:
> > In article <5ddf3f89-bf6d-48e0-a009-88867b7d7232
> > @a37g2000yqi.googlegroups.com>, [email protected] says...
> >
> >
> >
> >
> >
> > > On Nov 13, 9:37 am, "Leon" <[email protected]> wrote:
> > > > "brian roth" <[email protected]> wrote in message
> >
> > > > Have you thought about what the heat rising up to the mantel might to the
> > > > veneer/glue on the mantel?
> >
> > > When read the original post I was thinking the same thing.  When I
> > > built our mantel I used solid 2" Oak and placed it well above the
> > > minimum height recommended by the fireplace/stove manufacturer.  That
> > > dude still gets warm.  You might want to check into the durability of
> > > MDF when exposed to heat in the 120 to 130 degree range.  I don't know
> > > if it will degrade; but best to know now.
> >
> > I don't understand this business of mantels being exposed to heat.  
> > Maybe I'm just old fashioned but to me a mantel is a part of a brick or
> > stone fireplace and if it gets too hot for a cat to sleep on something
> > is badly wrong.
>
> A good part of the mantles being installed today are on insert
> fireplaces. These are essentially gas heaters or wood-burning stoves
> that have brick or tile faces surrounded by wood trim and a mantel.
> Little or no masonry
>
> For example, we installed a Buckmaster high efficiency wood stove in
> our house which is essentially a souped-up insert with external
> combustion air ducts, a catalytic combuster and a blower system. The
> unit builds in like a fireplace with ceramic tile front surrounded by
> mantel front and shelf. Buck provides specific installation
> instructions and clearances and our installation clearances exceed
> recommendations. The internal temperatures in these catalytic
> fireplaces gets above 1000 degrees and they put out heat. Heat rises
> from the face and the mantle gets warm. We had two gas fireplaces in
> our previous house and the mantle above the insert face got warm. The
> front of the masonry wood-burning fireplace and mantle in the older
> house we lived in got warm. I cannot imagine the front of a
> fireplace, that gets used, not getting warm.

The front gets plenty warm, but there's a foot or more of brick and
mortar between that warm and any wood with a real fireplace, and any
heat that gets to the wood has to go through the brick.

The mantel on a real fireplace isn't a shelf that sticks way out in
front of it, it sits on top of the masonry and is supported by it.

> I am just a little concerned that fireplace facing is the best place
> to use MDF. The temperatures involved with our current installation
> are in the 90 to 120 degree range. Far-far from any combustion
> concerns but I was suggesting the poster should look at long term
> effects of heat on his material. Some fireplaces sit unused during
> much of their lives. Ours is running now and will run muchof the them
> for the next 4-5 months. Will MDF or Veneered MDF hold up to this?

It was manufactured at around 400F.

> Also, depends on the cat. Our, now dearly departed, dog would have
> loved to lay on our warm mantle if he could have hoisted his aging 105
> pound butt up there. :^}
>
> RonB

Ll

"Leon"

in reply to brian roth on 12/11/2010 5:16 PM

13/11/2010 9:37 AM


"brian roth" <[email protected]> wrote in message
news:321b81bf-b0c1-4309-823f-8788cf10fec4@fj16g2000vbb.googlegroups.com...
> I'd like to build a fireplace mantel that features veneered panels.
>
> Unlike say a cabinet door, the other side of the panel will never be
> seen.
>
> Is it neccesary to veneer both sides? Does MDF move with moisture?


Have you thought about what the heat rising up to the mantel might to the
veneer/glue on the mantel?

Answering your question, MDF absolutely moves with moisture. Not so much
with relative humidity but if it gets wet and is not immediately wiped dry
it will swell.

Under normal circumstances temperatures being the same it is not necessarily
necessary to veneer both sides but it is best. With an extreme temp
difference you will be seeing it is probably a must and I would probably
want to cover the seams/ edges to hide expansion and contraction with temp
changes.

Rc

Robatoy

in reply to brian roth on 12/11/2010 5:16 PM

18/11/2010 9:10 AM

On Nov 18, 11:51=A0am, Hoosierpopi <[email protected]> wrote:
> On Nov 12, 8:16=A0pm, brian roth <[email protected]> wrote:
>
> > I'd like to build a fireplace mantel that features veneered panels.
>
> > Unlike say a cabinet door, the other side of the panel will never be
> > seen.
>
> > Is it neccesary to veneer both sides? =A0Does MDF move with moisture?
>
> My experience is that: It Moves
>
> I had a table top from Subway that I turn into a Router Table top. It
> was NOT laminated on the "bottom" and had that plastic edging
> installed (The type that fits in a kerf along the edges). After on
> year in the basement (cold, not dry) it sagged significantly and I
> knew it was my failure to seal the bottom surface with laminate or
> equivalent.
>
> For a one off project, the savings between good plywood and MDF are
> not worth taking the chance IMHO considering the labor involved ....

Plywood 'curls' just as easily when laminated in an unbalanced way.

ho

"http://www.Towood.com/"

in reply to brian roth on 12/11/2010 5:16 PM

14/11/2010 5:49 PM

On Nov 13, 9:16=A0am, brian roth <[email protected]> wrote:
> I'd like to build a fireplace mantel that features veneered panels.
>
> Unlike say a cabinet door, the other side of the panel will never be
> seen.
>
> Is it neccesary to veneer both sides? =A0Does MDF move with moisture?

If the other side of the panel is invisible, you can choose MDF with
veneer just one side.
MDF is stable with moisture .

Rc

Robatoy

in reply to brian roth on 12/11/2010 5:16 PM

14/11/2010 8:00 PM

On Nov 14, 8:49=A0pm, "http://www.Towood.com/" <[email protected]>
wrote:
> On Nov 13, 9:16=A0am, brian roth <[email protected]> wrote:
>
> > I'd like to build a fireplace mantel that features veneered panels.
>
> > Unlike say a cabinet door, the other side of the panel will never be
> > seen.
>
> > Is it neccesary to veneer both sides? =A0Does MDF move with moisture?
>
> If the other side of the panel is invisible, you can choose MDF with
> veneer just one side.
> MDF is stable with moisture .

I have worked with MDF for decades in many environments and MDF is NOT
stable with moisture.

MM

"Mike Marlow"

in reply to brian roth on 12/11/2010 5:16 PM

18/11/2010 10:08 PM

Hoosierpopi wrote:

>
> I had a table top from Subway that I turn into a Router Table top. It
> was NOT laminated on the "bottom" and had that plastic edging
> installed (The type that fits in a kerf along the edges). After on
> year in the basement (cold, not dry) it sagged significantly and I
> knew it was my failure to seal the bottom surface with laminate or
> equivalent.
>

I suspect the sagging occurred more from lack of support than from a failure
to seal the bottom. MDF does not even hold up its own weight well when not
well supported.

--

-Mike-
[email protected]

Bn

"BobS"

in reply to brian roth on 12/11/2010 5:16 PM

12/11/2010 10:08 PM

Brian,

Try this for some info

http://www.woodweb.com/knowledge_base/MDF_and_Wood_Veneer.html

Bob S.

"brian roth" <[email protected]> wrote in message
news:321b81bf-b0c1-4309-823f-8788cf10fec4@fj16g2000vbb.googlegroups.com...
> I'd like to build a fireplace mantel that features veneered panels.
>
> Unlike say a cabinet door, the other side of the panel will never be
> seen.
>
> Is it neccesary to veneer both sides? Does MDF move with moisture?

AB

Andrew Barss

in reply to brian roth on 12/11/2010 5:16 PM

13/11/2010 5:44 PM

Lew Hodgett <[email protected]> wrote:

: "brian roth" wrote:

:> I'd like to build a fireplace mantel that features veneered panels.
:>
:> Unlike say a cabinet door, the other side of the panel will never be
:> seen.
:>
:> Is it neccesary to veneer both sides? Does MDF move with moisture?
: ----------------------------------------
: It may not be necessary, but like chicken soup, maybe it has no
: medicinal value but hadn't ought to hurt.


I agree. However, there's no need to use fancy veneer for the other side -- any
cheap veneer (often called "backing veneer") of the same thickness would do.
Any veneer merchant will have something that will do.

-- Andy Barss

Mm

-MIKE-

in reply to brian roth on 12/11/2010 5:16 PM

14/11/2010 11:21 PM

On 11/14/10 10:00 PM, Robatoy wrote:
> I have worked with MDF for decades in many environments and MDF is NOT
> stable with moisture.

I used to frequent a Bob Evans restaurant that had a eating counter.
The waitress would always come up, wipe down the counter with a damp
cloth, then put down a fresh paper place mat. The thing would curl up
like a ribbon, because the paper fibers on one side got damp and expanded.
That's the same thing that happens to mdf.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

dd

"dadiOH"

in reply to brian roth on 12/11/2010 5:16 PM

13/11/2010 8:04 AM

brian roth wrote:
> I'd like to build a fireplace mantel that features veneered panels.
>
> Unlike say a cabinet door, the other side of the panel will never be
> seen.
>
> Is it neccesary to veneer both sides? Does MDF move with moisture?

I doubt it but the reason folks veneer both sides is to equalize the forces
applied to the sub-strate by the veneer. Especially so if you use water
base glue as the veneer absorbs that water and shrinks as it dries; that
shrinking applies a lot of bending force to the sub-strate.

--

dadiOH
____________________________

dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico



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