Got a "shabby chic" garden sign which is made from mdf. I want to protect it from the elements with some sort of varnish but I think it has to be sealed first?

The sign will hang on a wall in the garden, therefore it will be exposed 24/7.

Advice welcomed!

On 07/06/14 15:52, Jon Parker wrote:
Got a "shabby chic" garden sign which is made from mdf. I want to protect it from the elements with some sort of varnish but I think it has to be sealed first?

The sign will hang on a wall in the garden, therefore it will be exposed 24/7.

Advice welcomed!


Dilute the varnish first (white spirit if a traditional type, no idea
for some of the modern ones) then soak the sign in it. Repeat several
times. Have low expectations...

Jon Parker wrote:
Got a "shabby chic" garden sign which is made from mdf. I want to
protect it from the elements with some sort of varnish but I think it
has to be sealed first?

The sign will hang on a wall in the garden, therefore it will be
exposed 24/7.

Advice welcomed!

MDF is pretty much compressed cardboard, soaks water up like a sponge and is
completely useless for external applications.
I don't think it matters what you put on it, it will not survive long
outside.

On 07/06/2014 19:07, Tim Watts wrote:
On 07/06/14 15:52, Jon Parker wrote:
Got a "shabby chic" garden sign which is made from mdf. I want to
protect it from the elements with some sort of varnish but I think it
has to be sealed first?

The sign will hang on a wall in the garden, therefore it will be
exposed 24/7.

Advice welcomed!


Dilute the varnish first (white spirit if a traditional type, no idea
for some of the modern ones) then soak the sign in it. Repeat several
times. Have low expectations...

Immersion in diluted yatch varnish ought to do it. A properly applied
coat on real wood has lasted nearly a decade for me away from the sea.

Not sure that high gloss yatch varnish counts as shabby chic but it is
immensely durable if you obey the usage instructions to the letter.

--
Regards,
Martin Brown

On 07/06/2014 20:38, Phil L wrote:
Jon Parker wrote:
Got a "shabby chic" garden sign which is made from mdf. I want to
protect it from the elements with some sort of varnish but I think it
has to be sealed first?

The sign will hang on a wall in the garden, therefore it will be
exposed 24/7.

Advice welcomed!

MDF is pretty much compressed cardboard, soaks water up like a sponge and is
completely useless for external applications.
I don't think it matters what you put on it, it will not survive long
outside.



In Scandinavia they have mdf road signs apparently. Different grade of
course

On Saturday, June 7, 2014 8:38:59 PM UTC+1, Phil L wrote:
Jon Parker wrote:

Got a "shabby chic" garden sign which is made from mdf. I want to
protect it from the elements with some sort of varnish but I think it
has to be sealed first?

The sign will hang on a wall in the garden, therefore it will be
exposed 24/7.

Advice welcomed!

glass case & dehumidifier

MDF is pretty much compressed cardboard, soaks water up like a sponge and is
completely useless for external applications.
I don't think it matters what you put on it, it will not survive long
outside.

Quite. A soak in dilute non-waterbased varnish may work for a while, but dont know how long. I've heard of sheet paper getting over a year outdoors this way.


NT

On Sat, 7 Jun 2014 07:52:43 -0700 (PDT), Jon Parker
wrote:

Advice welcomed!

A friend of mine (the one who had a slight mishap with a canoe and
expanding foam) made a fine sign on MDF for his daughters chicken
house. As those who are aware of the canoe mishap saga may appreciate
he is a somewhat unwordly soul despite his intelligence. Having made
the sign he was much put out to discover that signs for chicken houses
went on the outside, not the inside for only the chickens to admire.

Varnish wasn't an option as it would have disrupted the rather fine
artwork so he obtained a length of PVC drainpipe which the sign could
fit into and assorted fittings and constructed a vacuum chamber. This
was connected to an old fridge compressor as the vacuum pump. He put
the sign in, filled it with a slow setting resin, set it all going and
went for a cup of tea. To the amazement of those of us familiar with
some of his Heath Robinson efforts after about an hour he had a
respectably low pressure. He left it for about another hour then
slowly released the vacuum and allowed the apparatus to come back to
atmospheric pressure. The sign was allowed to rest in the resin for
an hour then taken out , allowed to drain and left for several hours
for the resin to set.

Several years later and it is still in place and in perfect condition.
The apparatus would have been reusable had he not forgotten to pour
out the surplus resin and clean the pipes where resin foaming as the
air was extracted from the MDF had collected.

On Sunday, 8 June 2014 12:56:39 UTC+1, Peter Parry wrote:
On Sat, 7 Jun 2014 07:52:43 -0700 (PDT), Jon Parker

wrote:



Advice welcomed!



A friend of mine (the one who had a slight mishap with a canoe and

expanding foam) made a fine sign on MDF for his daughters chicken

house. As those who are aware of the canoe mishap saga may appreciate

he is a somewhat unwordly soul despite his intelligence. Having made

the sign he was much put out to discover that signs for chicken houses

went on the outside, not the inside for only the chickens to admire.



Varnish wasn't an option as it would have disrupted the rather fine

artwork so he obtained a length of PVC drainpipe which the sign could

fit into and assorted fittings and constructed a vacuum chamber. This

was connected to an old fridge compressor as the vacuum pump. He put

the sign in, filled it with a slow setting resin, set it all going and

went for a cup of tea. To the amazement of those of us familiar with

some of his Heath Robinson efforts after about an hour he had a

respectably low pressure. He left it for about another hour then

slowly released the vacuum and allowed the apparatus to come back to

atmospheric pressure. The sign was allowed to rest in the resin for

an hour then taken out , allowed to drain and left for several hours

for the resin to set.



Several years later and it is still in place and in perfect condition.

The apparatus would have been reusable had he not forgotten to pour

out the surplus resin and clean the pipes where resin foaming as the

air was extracted from the MDF had collected.

May have been better pulling a vaccuum without the resin in first, (to purge the air), then "somehow" introducing the resin into the chamber, then de-pressurising - so atmospheric pressure forced it in....

Still it worked obviously

Jim K

On 08/06/2014 12:56, Peter Parry wrote:
Several years later and it is still in place and in perfect condition.
The apparatus would have been reusable had he not forgotten to pour
out the surplus resin and clean the pipes where resin foaming as the
air was extracted from the MDF had collected.

My vote on the sign would be a coating epoxy - thin runny stuff designed
for this. Then varnish to protect the epoxy from UV.

But I wouldn't use MDF.

Andy

The sign, if an external one, may have been made from exterior grade mdf



1220x2440x18mm Exterior Grade MDF

Description

Medite Exterior is an MDF panel developed specifically for use in a wide range of external applications in accordance with MDF-H2 as defined in EN 622 part 5 and gives all the design freedom of Standard MDF. Used as a substitute for softwood, hardwood, plywood, plastic and metal in non-stressed applications. It can be used for a wide range of external applications including: External signs, shop fronts and external woodwork including fascias, exterior mouldings, door parts - raised and fielded panels, garden furniture components, exterior display
stands, marine craft interiors and sports score boards.

Never tried it myself though I have seen various pieces in Garden centres designed for external use using it.

What I have seen has had a slight green tinge to it in its narural stste.