Hi everyone, I am working on a large (24in x 34in ) shadow box that needs to
be painted gloss black. It needs to be done cheaply so I used some MDF that
I had laying around. I'm using cheapo spray paint from WalMart and am
having trouble with the rounded edges not taking the paint. The flat
surfaces are fine but where I used a round over bit the MDF is behaving like
end grain-it's just sucking up the paint. I shot a primer coat and three
top coats and still cannot get a nice finish. Before painting I also sanded
to 220 grit so it should be smooth enough. Can anyone shed light on this
problem?
Thanks,
Gene
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"Gene T" <[email protected]> wrote in message
news:[email protected]...
> Before painting I also sanded to 220 grit so it should be smooth enough.
> Can anyone shed light on this problem?
> Thanks,
> Gene
>
When ever I finish MDF with paint I prime the hell out of it. I use Krylon
spray primer and lay it on until it looks like it will run, then I let it
dry, and put on one or two more heavy coats, with a light sanding in
between. Keep laying on the primer until it quits absorbing into the MDF.
Greg
You can also buy special primer for MDF too :)
Most big box tool stores should have it.
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"Gene T" <[email protected]> wrote in message
news:[email protected]...
> Hi everyone, I am working on a large (24in x 34in ) shadow box that needs
to
> be painted gloss black. It needs to be done cheaply so I used some MDF
that
> I had laying around. I'm using cheapo spray paint from WalMart and am
> having trouble with the rounded edges not taking the paint. The flat
> surfaces are fine but where I used a round over bit the MDF is behaving
like
> end grain-it's just sucking up the paint. I shot a primer coat and three
> top coats and still cannot get a nice finish. Before painting I also
sanded
> to 220 grit so it should be smooth enough. Can anyone shed light on this
> problem?
Unfortunately I work with MDF all too often, I find no joy out in working
with it whatsoever.
I make a light wash of PVA and water and "pre-prime" (hey, did I just invent
a new term?) the MDF edges with that, let it dry and then prime & paint
normally. Occasionally I may also need to do some filling but I do that
after priming and usually add a second coat of primer over the filler.
It works for me, anyway.
- Andy
"B a r r y" <[email protected]> wrote in message
news:[email protected]...
> Andy McArdle wrote:
>
> > I make a light wash of PVA and water and "pre-prime" (hey, did I just
invent
> > a new term?) the MDF edges with that
>
> A.K.A. "Glue Size".
Ah. Thank you. Terminology's one of the problems with being self-taught...
- Andy
> > Terminology's one of the problems with being self-taught...
>
> I know the feeling.
Lessee... glue sizing isn't about wallpaper, tenons go in mortises instead
of chucks, and if a plane flies you're doing something wrong? Next I'll be
told a jig is not when you hit your thumb and lathing doesn't involve
plaster.
No. No, I'm not getting the hang of this. I'm going back to pointy sticks.
- Andy
In article <[email protected]>,
<[email protected]> wrote:
>I used shellac for this purpose and found that it did a good job of
>sealing the surface. After each coat (did several) I sanded the
>surface to make it smooth. Has anyone tried shellac as a primer? Have
>you found that the other methods mentioned did a better job?
>
I haven't used plain shellac, but I have used Zinsser BIN primer,
which is a shellac based primer with white pigment added. It worked
very well for me.
--
Larry Wasserman Baltimore, Maryland
[email protected]
Gene T wrote:
> Hi everyone, I am working on a large (24in x 34in ) shadow box that needs to
> be painted gloss black. It needs to be done cheaply so I used some MDF that
> I had laying around. I'm using cheapo spray paint from WalMart and am
> having trouble with the rounded edges not taking the paint. The flat
> surfaces are fine but where I used a round over bit the MDF is behaving like
> end grain-it's just sucking up the paint. I shot a primer coat and three
> top coats and still cannot get a nice finish. Before painting I also sanded
> to 220 grit so it should be smooth enough. Can anyone shed light on this
> problem?
> Thanks,
> Gene
>
The spray paints (Pressure Packs) are just to thin for MDF edges. Get
out a brush and give them a coat of acrylic Black or undercoat-sealer.
Sand back nice and smooth and then spray. All should be OK.
Regards
John
"Gene T" <[email protected]> wrote in
news:[email protected]:
> Hi everyone, I am working on a large (24in x 34in ) shadow box that
> needs to be painted gloss black. It needs to be done cheaply so I
> used some MDF that I had laying around. I'm using cheapo spray paint
> from WalMart and am having trouble with the rounded edges not taking
> the paint. The flat surfaces are fine but where I used a round over
> bit the MDF is behaving like end grain-it's just sucking up the paint.
> I shot a primer coat and three top coats and still cannot get a nice
> finish. Before painting I also sanded to 220 grit so it should be
> smooth enough. Can anyone shed light on this problem?
> Thanks,
> Gene
>
An article in FWW and/or FHB showed sealing the cut edges of MDF with
thinned drywall taping compound. Fills, smooths and pretty much seals the
edges. Use before priming.
Or so I'm told. I use very little of the stuff, personally.
Patriarch
I have used it ith success.
I like shellac for it's quick-drying, and it "sandability".
-Steve
<[email protected]> wrote in message
news:[email protected]...
> I used shellac for this purpose and found that it did a good job of
> sealing the surface. After each coat (did several) I sanded the
> surface to make it smooth. Has anyone tried shellac as a primer? Have
> you found that the other methods mentioned did a better job?
>
In article <[email protected]>,
"Gene T" <[email protected]> wrote:
> Hi everyone, I am working on a large (24in x 34in ) shadow box that needs to
> be painted gloss black. It needs to be done cheaply so I used some MDF that
> I had laying around. I'm using cheapo spray paint from WalMart and am
> having trouble with the rounded edges not taking the paint. The flat
> surfaces are fine but where I used a round over bit the MDF is behaving like
> end grain-it's just sucking up the paint. I shot a primer coat and three
> top coats and still cannot get a nice finish. Before painting I also sanded
> to 220 grit so it should be smooth enough. Can anyone shed light on this
> problem?
> Thanks,
> Gene
Think sponge.
You need to seal the porosity. I use lacquer-based automotive finishing
putty.
In article <[email protected]>,
"Gene T" <[email protected]> wrote:
Now I wish I had used polar instead!!!
> Gene
...working with that stuff can give you a disorder.
.
.
.
.
.
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.
I seldom make fun of a typo..sorry 'bout that.
Thanks for all of the useful info guys. I didn't realize how porous MDF
was. Now I wish I had used polar instead!!!
Gene
"Gene T" <[email protected]> wrote in message
news:[email protected]...
> Hi everyone, I am working on a large (24in x 34in ) shadow box that needs
> to be painted gloss black. It needs to be done cheaply so I used some MDF
> that I had laying around. I'm using cheapo spray paint from WalMart and
> am having trouble with the rounded edges not taking the paint. The flat
> surfaces are fine but where I used a round over bit the MDF is behaving
> like end grain-it's just sucking up the paint. I shot a primer coat and
> three top coats and still cannot get a nice finish. Before painting I
> also sanded to 220 grit so it should be smooth enough. Can anyone shed
> light on this problem?
> Thanks,
> Gene
>
> --
>
>
>
>
>
> This message has been scanned by Norton Anti-virus software
>