Jb

"JWBH"

21/04/2007 5:59 AM

PVA waterproof adhesive on MDF

Have a piece of oak veneered mdf that i wish to use to make a shelf along
side the bath.

The oak veneer does not cover all the edges, so my plan is to seal the edges
and to then use a ronseal quick drying water based matt varnish to paint
the whole thing.

I can see that PVA is often advertised for use as a sealant. A little while
ago I bought a tub of Wickes PVA water proof adhesive. It says not to glue
two non porous materials that is subjected to wet. As an experiement I
found soaking things with water makes the adhesive go soft again and come
adrift.

So is this 'so called' waterproof adhesive suitable as a sealant on this mdf
please. Or is PVA waterproof adhesive essentially different from PVA
sealant and so not suitable to seal the mdf. thanks


This topic has 9 replies

Rd

Robatoy

in reply to "JWBH" on 21/04/2007 5:59 AM

21/04/2007 7:17 AM

On Apr 21, 3:20 am, "JWBH" <[email protected]> wrote:
> "Lew Hodgett" <[email protected]> wrote in message
>
> news:[email protected]...
>
> > JWBH wrote:
> > > Have a piece of oak veneered mdf that i wish to use to make a shelf
> > along
> > > side the bath.
> > <snip>
>
> > Don't want to burst your bubble, but you can't get there from here.
>
> > Doesn't make any difference how you try to seal the MDF, my guess is that
> > it will take about 6 months before the MDF starts swelling from water
> > splash and high humidity in the bath room.
>
> > If you want an oak shelf, try oak veneer over a plywood core.
> > Lew
>
> thanks for the advice. as a matter of interest can this adhesive be used
> as a sealer generally?

Talk to sign makers who do out-door stuff. They have tricks they use
to seal MDF.

Gj

GROVER

in reply to "JWBH" on 21/04/2007 5:59 AM

23/04/2007 5:35 AM

On Apr 21, 1:59 am, "JWBH" <[email protected]> wrote:
> Have a piece of oak veneered mdf that i wish to use to make a shelf along
> side the bath.
>
> The oak veneer does not cover all the edges, so my plan is to seal the edges
> and to then use a ronseal quick drying water based matt varnish to paint
> the whole thing.
>
> I can see that PVA is often advertised for use as a sealant. A little while
> ago I bought a tub of Wickes PVA water proof adhesive. It says not to glue
> two non porous materials that is subjected to wet. As an experiement I
> found soaking things with water makes the adhesive go soft again and come
> adrift.
>
> So is this 'so called' waterproof adhesive suitable as a sealant on this mdf
> please. Or is PVA waterproof adhesive essentially different from PVA
> sealant and so not suitable to seal the mdf. thanks

Several previous posts have refered to sign makers. Highway
departments responsible for signage which must withstand exterior and
moist conditions use a material called MDO (medium density overlay).
It has a smooth paper surface suitable for painting. I suspect the
factory treats the sheets to withstand the elements.
For your application, I also would not recommend MDF.
Joe G

wn

"woodstuff"

in reply to "JWBH" on 21/04/2007 5:59 AM

21/04/2007 3:30 PM

<snip>
| So is this 'so called' waterproof adhesive suitable as a sealant on this
mdf
| please. Or is PVA waterproof adhesive essentially different from PVA
| sealant and so not suitable to seal the mdf. thanks

Once I used some water-proof glue on a veneer and got a stain that wouldn't
go a way.. maybe I'm the only one in this world that this has ever happened
to....

woodstuff



LH

Lew Hodgett

in reply to "JWBH" on 21/04/2007 5:59 AM

23/04/2007 4:47 PM

Leon wrote:

> The highway department uses a paper faced mdf for road signs. I
think it is
> the paint that is the key element here.

Think you are referring to MDO which is actually plywood with paper
face(s) depending on application.

Not aware of a product consisting of MDF core with paper face(s).

Lew

LH

Lew Hodgett

in reply to "JWBH" on 21/04/2007 5:59 AM

21/04/2007 1:04 PM

JWBH wrote:

>
> thanks for the advice. as a matter of interest can this adhesive be used
> as a sealer generally?


Strictly a personal opinion.

Adhesives are adhesives, sealers are sealers.

Different horses for different courses.

Lew

Lr

"Leon"

in reply to "JWBH" on 21/04/2007 5:59 AM

23/04/2007 12:19 PM


"Robatoy" <[email protected]> wrote in message
news:[email protected]...
> Talk to sign makers who do out-door stuff. They have tricks they use
> to seal MDF.


The highway department uses a paper faced mdf for road signs. I think it is
the paint that is the key element here.

Jb

"JWBH"

in reply to "JWBH" on 21/04/2007 5:59 AM

21/04/2007 7:20 AM


"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> JWBH wrote:
> > Have a piece of oak veneered mdf that i wish to use to make a shelf
> along
> > side the bath.
> <snip>
>
> Don't want to burst your bubble, but you can't get there from here.
>
> Doesn't make any difference how you try to seal the MDF, my guess is that
> it will take about 6 months before the MDF starts swelling from water
> splash and high humidity in the bath room.
>
> If you want an oak shelf, try oak veneer over a plywood core.
> Lew

thanks for the advice. as a matter of interest can this adhesive be used
as a sealer generally?

LH

Lew Hodgett

in reply to "JWBH" on 21/04/2007 5:59 AM

21/04/2007 6:39 AM

JWBH wrote:
> Have a piece of oak veneered mdf that i wish to use to make a shelf
along
> side the bath.
<snip>

Don't want to burst your bubble, but you can't get there from here.

Doesn't make any difference how you try to seal the MDF, my guess is
that it will take about 6 months before the MDF starts swelling from
water splash and high humidity in the bath room.

If you want an oak shelf, try oak veneer over a plywood core.


Lew

MR

"Mike Richardson"

in reply to "JWBH" on 21/04/2007 5:59 AM

22/04/2007 11:47 AM

>> > > Have a piece of oak veneered mdf that i wish to use to make a shelf
>> > along
>> > > side the bath.
>> > <snip>
>>
>> > Don't want to burst your bubble, but you can't get there from here.
>>
>> > Doesn't make any difference how you try to seal the MDF, my guess is
>> > that
>> > it will take about 6 months before the MDF starts swelling from water
>> > splash and high humidity in the bath room.
>>
>> > If you want an oak shelf, try oak veneer over a plywood core.
>> > Lew
>>
>> thanks for the advice. as a matter of interest can this adhesive be
>> used
>> as a sealer generally?
>
> Talk to sign makers who do out-door stuff. They have tricks they use
> to seal MDF.
>

Permanantly, or for a lifetime of say 5-6 years? Serious question - as I
wonder if there are secret herbs and spices to seal it as opposed to hide
the problem for long enough for decent life in use of that specific
application. I shy away from MDF ever since I read here about the problems.
I must admit to not having been sufficiently educated on the dust problems
of MDF and the hit the tools take. Haven't used it since.

I guess my brain tells me MDF is not the product for wet areas, just as chip
board isn't (even though it is used a LOT in Aus for just that...)

So budget may lead to MDF/Chipboard, but QUALITY leads to other
alternatives. Almost makes me think of another wise phrase ex the
Wreck..."Buy once, cry once".

2c

Mike
Brisbane Aus.


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