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Flatening hardboard?

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Markndawoods

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Jun 27, 2009, 8:03:51 PM6/27/09
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After I built my workbench, I made it so I could use a 36" x 72" piece of
hardboard drop in, being able to change it out when necessary.
Unfortunately, the sheet I had on hand had been leaning against the wall
with something behind it, making it quite uneven. After cutting it to size
it will not lay flat.

Does anyone have any idea as to how I might be able to get it to lay flat
again, without gluing down? Is that even possible?

Any ideas is much appreciated!

markndawoods


Puckdropper at dot

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Jun 27, 2009, 8:43:30 PM6/27/09
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"Markndawoods" <marknd...@molalla.net> wrote in
news:GpSdnVEiwK36LtvX...@molalla.net:

Sometimes gravity is your friend here. Other times it's just not fast
enough.

Hardboard is a pressed paper board that does survive getting wet
reasonably well. You might try a combination of gentle heat and moisture
to get it to flatten out a bit. (Leave it out in the driveway, turning
often?)

You might try a temporary spray adhesive, but sometimes temporary
adhesives become quite permanent after several months.

Puckdropper
--
"The potential difference between the top and bottom of a tree is the
reason why all trees have to be grounded..." -- Bored Borg on
rec.woodworking

To email me directly, send a message to puckdropper (at) fastmail.fm

-MIKE-

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Jun 27, 2009, 9:24:57 PM6/27/09
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Eight bucks and a trip to the lumber store. :-)


--

-MIKE-

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

Elrond Hubbard

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Jun 27, 2009, 9:28:33 PM6/27/09
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Puckdropper <puckdropper(at)yahoo(dot)com> wrote in
news:008af213$0$24355$c3e...@news.astraweb.com:

>> Does anyone have any idea as to how I might be able to get it to lay
>> flat again, without gluing down? Is that even possible?
>>
>> Any ideas is much appreciated!

> Sometimes gravity is your friend here. Other times it's just not fast


> enough.
>
> Hardboard is a pressed paper board that does survive getting wet
> reasonably well. You might try a combination of gentle heat and
> moisture to get it to flatten out a bit. (Leave it out in the
> driveway, turning often?)

You might also try lightly wetting (damp sponge) the concave side, then
putting the piece on the table convex side up and weighting it down. It
cups because of the difference in moisture content between the two faces.

8d nails every 4 inches on the edges and every 6 inches in the field will
also be effective, if you're in a rush ;o)

cl...@snyder.on.ca

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Jun 27, 2009, 9:39:04 PM6/27/09
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Dampen it and weight it down.

Tom Veatch

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Jun 27, 2009, 9:45:32 PM6/27/09
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On Sat, 27 Jun 2009 17:03:51 -0700, "Markndawoods"
<marknd...@molalla.net> wrote:

>Does anyone have any idea as to how I might be able to get it to lay flat
>again, without gluing down? Is that even possible?

Definitely possible. As others have indicated, moisture will do it.
You didn't say whether it was tempered or not, and I'm not sure that
would make a difference, anyway.

I built a mantle for a while back, and the part between the shelf and
the top of the firebox was filled in with some thin sheets of oak. Too
thin to tongue and groove so I decided to back them with hardboard.
Used PVA glue to laminate them and the moisture content of the glue
durn near caused the assembly to bow into a circle. Don't remember now
which direction it bowed, but moisture will definitely cause it to
move, or straighten out if you guess right on which side to dampen.

Tom Veatch
Wichita, KS
USA


John Grossbohlin

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Jun 27, 2009, 9:56:08 PM6/27/09
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"Markndawoods" <marknd...@molalla.net> wrote in message
news:GpSdnVEiwK36LtvX...@molalla.net...

I'd be inclined to put it down with contact cement around the edges with a
few dabs in the field. I've never been happy with loose hard board tops as
they always seem to be loose--at least they feel that way compared to
working on solid maple or solid plywood. The contact cement can be loosened
with heat if it doesn't peel off easily at replacement time.

John


Lew Hodgett

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Jun 27, 2009, 10:23:05 PM6/27/09
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"Markndawoods" wrote:


> After cutting it to size it will not lay flat.
>
> Does anyone have any idea as to how I might be able to get it to lay
> flat again, without gluing down? Is that even possible?

Bricks and/or concrete blocks for weight and patience on your part.

Weight it down, wait 30 days minimum.

Lew


Doug Winterburn

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Jun 27, 2009, 10:55:42 PM6/27/09
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doubleback tape and a harborfreight 18 ga brad gun does the job - just a
few brads around the perimeter until it lays flat.

Markndawoods

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Jun 28, 2009, 1:32:33 AM6/28/09
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>
>>After I built my workbench, I made it so I could use a 36" x 72" piece of
>>hardboard drop in, being able to change it out when necessary.
>>Unfortunately, the sheet I had on hand had been leaning against the wall
>>with something behind it, making it quite uneven. After cutting it to size
>>it will not lay flat.
>>
>>Does anyone have any idea as to how I might be able to get it to lay flat
>>again, without gluing down? Is that even possible?
>>
>>Any ideas is much appreciated!
>>
>>markndawoods
>>
> Dampen it and weight it down.

I thought of that, but was afraid to put any moisture to HB, thinking I
would end up with a flaked or a powder top before it was all over with!

I will cautiously try this approach.

Thanks for everyone's input.

Jeff Gorman

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Jun 28, 2009, 3:30:44 AM6/28/09
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"Markndawoods" <marknd...@molalla.net> wrote

Many years ago, in my youth and innocence - try anything once style, I bent
some perforated hardboard round a former to make a dirty-linen chest -
obviously tricky because it would prefer to bend along the lines of the
holes.

I managed it by plying a steam jet to both sides of the board while coaxing
it round a frame.

This makes me wonder whether a domestic steam laundry iron might do the job
of flattening this area?

Jeff

--
Jeff Gorman, West Yorkshire, UK
email : Username is amgron
ISP is clara.co.uk
www.amgron.clara.net


Leon

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Jun 28, 2009, 10:39:34 AM6/28/09
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"Markndawoods" <marknd...@molalla.net> wrote in message
news:GpSdnVEiwK36LtvX...@molalla.net...

Just try setting it out on a flat surface in dirrect sun light on a hot
afternoon.


Puckdropper at dot

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Jun 28, 2009, 2:24:38 PM6/28/09
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"Markndawoods" <marknd...@molalla.net> wrote in
news:S_-dnRRjHIDrndrX...@molalla.net:

>
> I thought of that, but was afraid to put any moisture to HB, thinking
> I would end up with a flaked or a powder top before it was all over
> with!
>
> I will cautiously try this approach.
>
> Thanks for everyone's input.
>

I got a couple pieces of tempered hardboard wet last winter while
fighting a bulge on the ice rink. (Woodworking tip: Sometimes it's not
the size of your fastener, it's the location of your fastener.) There
was minimal swelling, and it went back to normal size.

It's not like the compressed sawdust product that crumbles when it gets
wet.

Phisherman

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Jun 28, 2009, 5:23:58 PM6/28/09
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On Sun, 28 Jun 2009 09:39:34 -0500, "Leon" <lcb1...@swbell.dotnet>
wrote:

You can try laying it on the lawn in the sun. Place the board like a
coffee cup that is upsidedown. The warm moisture underneath should
expand that side. I have used this method with doors and it works 80%
of the time. For you application I'd use carpet tape too.

Groggy

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Jun 30, 2009, 3:24:35 AM6/30/09
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I'd go with this one too. Put a bucket of water on the lawn, wait an
hour then lay the board where the water was. Wait till the board
flattens then remove it. Lay it flat until it dries.

Brian Henderson

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Jun 30, 2009, 9:32:41 PM6/30/09
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Find yourself a good, flat surface, dampen the convex side (not dripping
wet, just a fine spray works) and pile on bricks or sandbags, whatever
you have around, until it dries and flattens. It may never be
completely flat, fair warning, but it will take out the majority of the
bend. If you can get it down to a nearly acceptable level, mount it
concave side up and you can hold down the perimeter with a few
well-placed nails or maybe even double-sided tape, depending on the
amount of bend you still have.

Unless you have a really good reason not to though, it'll be faster and
easier to just go get yourself another piece of hardboard, they're cheap
at any home center.

Leon

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Jun 30, 2009, 11:49:26 PM6/30/09
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"Brian Henderson" <BrianL.H...@NOSPAM.verizon.net> wrote in message
news:Z0z2m.1861$9l4...@nwrddc01.gnilink.net...

>
>
> Find yourself a good, flat surface, dampen the convex side (not dripping
> wet, just a fine spray works) and pile on bricks or sandbags, whatever you
> have around, until it dries and flattens.

Seems to me wetting the convex side would worsen matters. Typically the
material bows in on the dry side.


Brian Henderson

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Jul 1, 2009, 3:43:28 PM7/1/09
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You're right, I should have said concave side, although wetting both
probably doesn't hurt either. The way he described it didn't seem to me
to be a problem with wetness, but with leaning against a wall
unsupported so that gravity was responsible for the problem.

Leon

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Jul 1, 2009, 4:18:06 PM7/1/09
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"Brian Henderson" <BrianL.H...@NOSPAM.verizon.net> wrote in message
news:A%O2m.1953$9l4...@nwrddc01.gnilink.net...


I actually would not suggest wetting at all but apparently the damage is
done and it is not much of a loss either way. My experience with this
compressed wood product stuff is that once it gets wet it swells and stays
that way.
Now warped ply wood would possibly be another matter concerning wetting it
down.

Last eeek Swingman and I were building kitchen cabinets and we had 1/4" oak
plywood leaning against a fence, in the sun, for about a half day. It
warped pretty badly in a mattter of a few hours. IIRC the next day he put
more plywood in the shade with no ill effects.

Mike Stanford

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Jul 1, 2009, 5:11:44 PM7/1/09
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"Markndawoods" <marknd...@molalla.net> wrote in message
news:GpSdnVEiwK36LtvX...@molalla.net...

My father (a carpenter and joiner all his working life) told me that to get
hardboard to go flat you should dampen the backside of it just before you
use it and then pin it down. As it dries, it shrinks slightly and pulls
itself flat.

Hope this helps
Micky


Mark Haveman

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Jul 16, 2009, 1:55:17 PM7/16/09
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Stick it down with double sided tape or buy another sheet.

Markndawoods <marknd...@molalla.net> wrote in message
news:GpSdnVEiwK36LtvX...@molalla.net...

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