S

01/12/2012 9:34 PM

Sanding before Priming

I was curious as to how much sanding is usually necessary before priming.

Is it normal to sand old or even relatively new paint completely off before=
priming, or just enough so that the primer adheres?

I ask because I'm restoring some old artwork on a plywood cabinet, and if I=
don't sand it off completely it would be easier to restore the art by mask=
ing and going over it with each of the three or four colors originally used=
rather than to have to start from scratch.

The artwork was originally done in lacquer paint, however the paint I'm usi=
ng to restore it is latex.

Thanks.

Darren Harris
Staten Island, New York.


This topic has 14 replies

SS

Searcher7

in reply to [email protected] on 01/12/2012 9:34 PM

04/12/2012 3:44 PM

On Dec 2, 4:58=A0pm, Ed Pawlowski <[email protected]> wrote:
> On Sun, 2 Dec 2012 12:33:34 -0800 (PST), [email protected]
> wrote:
>
> >On Sunday, December 2, 2012 12:50:47 AM UTC-5, Ed Pawlowski wrote:
> >> Painting over lacquer with latex is just repainting, not restoration.
>
> >I'm not sure what you mean by that. As long as the surface is smooth the=
three different color matched latex paints I have, which are actually prim=
er and paint in one, will be used on the entire side which was actually ori=
ginally stenciled and sprayed. The base/background color, the second and th=
en third color, followed lastly by the black outlines.
>
> When you "restore" something, you bring it back to original condition.
> If you have a '55 Chevy and replace the chrome on the bumper with
> silver paint, it is just painted, not restored. =A0Replacing lacquer
> with latex is not a restoration.

I still don't see the parallel. I'll be using latex and a clear gloss
over that for protection. Many other have done this in restoring their
cabinets and the resulting artwork looks factory new.

Darren Harris
Staten Island, New York.

FH

Father Haskell

in reply to [email protected] on 01/12/2012 9:34 PM

06/12/2012 2:10 PM

On Dec 2, 12:34=A0am, [email protected] wrote:
> I was curious as to how much sanding is usually necessary before priming.
>
> Is it normal to sand old or even relatively new paint completely off befo=
re priming, or just enough so that the primer adheres?
>
> I ask because I'm restoring some old artwork on a plywood cabinet, and if=
I don't sand it off completely it would be easier to restore the art by ma=
sking and going over it with each of the three or four colors originally us=
ed rather than to have to start from scratch.
>
> The artwork was originally done in lacquer paint, however the paint I'm u=
sing to restore it is latex.

Only two things will stick reliably to cured lacquer -- lacquer
or shellac. Clean, scuff with 220 until no longer glossy.
Seal with clear dewaxed shellac (Seal Coat), scuff when
dry, and paint with whatever you like. The shellac will also
seal the masking tape edges to create sharper lines and
prevent paint from seeping under.

S

in reply to [email protected] on 01/12/2012 9:34 PM

06/12/2012 9:06 AM

On Tuesday, December 4, 2012 9:54:06 PM UTC-5, Mike Marlow wrote:
> Searcher7 wrote:
>
> > On Dec 2, 3:40 pm, "Mike Marlow" <[email protected]> wrote:
>
> >> [email protected] wrote:
>
> >>
>
> >>> Ok. I'm not 100 sure what you mean by "unfeathered edges". Is that
>
> >>> were two different colors meet? I will obviously be using brushes.
>
> >>> Foam for the main colors and a thick liner brush for the black
>
> >>> outlines.
>
> >>
>
> >> Unfeathered edges - the raw edge of the old paint. Imagine a large
>
> >> paint chip missing - the edges of the chip. On a thin coat of paint
>
> >> that edge may not be very significant but on a thicker coat it would
>
> >> be very significant. You'd want to feather that down to blend it
>
> >> into the wood.
>
> >
>
> > The original paint was lacquer and therefore somewhat transparent. If
>
> > you sand it too much the color underneath the color you are sanding
>
> > stars to come through. It doesn't chip, so there are no unfeathered
>
> > edges to worry about.
>
> >
>
> >>> But as far as sanding *after* I finish re-painting. Camn this be
>
> >>> done without having to worry about bleed over?
>
> >>
>
> >> Bleed over? Don't understand what you mean.
>
> >
>
> > When one color contaminates an adjoining color.
>
> >
>
>
>
> Got it. You meant bleed through. As for sanding after re-painting... you
>
> can if you use a fine grit and are careful how much you sand. Even a very
>
> fine grit will cut through a top coat at some point, exposing the underlying
>
> coats. That's not really bleed through though. Bleed through is when the
>
> underlying colors are still (partially) visible through your undisturbed top
>
> coat. Think - not enough top coat.

No. "Bleed through". When one color contaminates an *adjoining* color. I'm hoping the sanded particles from one color don't embed themselves in the adjoining color.

> I'm sorry to have to ask - if you've already said why, but why is it that
>
> you are thinking about sanding your finished top coat? There can indeed be
>
> good reasons to do this, but it also depends on the paint in question. Not
>
> all paints will shine if knocked down with sandpaper. Don't want to answer
>
> your question incorrectly and steer you wrong.

I may decide to do more than one coat depending on how it comes out. I'd like the finish to be as smooth as possible.

Thanks.

Darren Harris
Staten Island, New York.

S

in reply to [email protected] on 01/12/2012 9:34 PM

09/12/2012 11:04 AM

On Sunday, December 2, 2012 6:34:51 PM UTC-5, -MIKE- wrote:
> On 12/2/12 2:33 PM, [email protected] wrote:
>=20
> > On Sunday, December 2, 2012 1:08:17 PM UTC-5, -MIKE- wrote:
>=20
> >> If whatever you're applying on top will stick to what's beneath it, yo=
u
>=20
> >>
>=20
> >> don't need to sand down to wood. With many woods, whatever is already =
on
>=20
> >> the surface is better to paint over than bare wood, anyway.
>=20
> >
>=20
> > In a question involving a different but similar project, *priming* over=
a clean, lightly sanded surface that still has paint is no problem, correc=
t?
>=20
> >
>=20
>=20
>=20
> Not that I know of. Priming over a surface that has different,=20
>=20
> contracting colors can help keep the top color even.

I used a foam roller. One coat with horizontal strokes, the second with ve=
rtical strokes and the third with horizontal strokes again, and I can still=
couldn't completely get rid of the "parquet-like" pattern. So I hope when =
it is painted over it will look ok.

> >> Smooth is relative with paint, as well. I can't tell you how many time=
s
>=20
> >> I've sanded a drywall patch "perfectly smooth" only to see the borders
>=20
> >> after painting. If there's any texture or artwork on top, it often hid=
es
>=20
> >> those imperfections. But a single color, smooth topcoat will often sho=
w
>=20
> >> them.
>=20
> >>
>=20
> >>
>=20
> >>
>=20
> >> The solution might be building up a couple layers of primer with flat
>=20
> >> sanding in between coats. Good auto-body guys are maters of this.
>=20
> >
>=20
> > I don't want to lose the original artwork completely, since it will be =
my guide when re-painting.
>=20
> >
>=20
> > But as far as sanding *after* I finish re-painting. Camn this be done w=
ithout having to worry about bleed over?
>=20
> >
>=20
>=20
>=20
> I don't know what "bleed over" means, and I'm certainly no paint expert.
>=20
> But I would never sand the final, finish coat of paint. Maybe some do.

I'll be force to use brushes at certain points and assume I'll have to deal=
with some streaks as a result, so I was thinking a light sanding might hel=
p. (Someone even mentioned using #000 steel wool to "feather" any slight ra=
ises).

Thanks.

Darren Harris
Staten Island, New York.

SS

Searcher7

in reply to [email protected] on 01/12/2012 9:34 PM

04/12/2012 3:41 PM

On Dec 2, 3:40=A0pm, "Mike Marlow" <[email protected]> wrote:
> [email protected] wrote:
>
> > Ok. I'm not 100 sure what you mean by "unfeathered edges". Is that
> > were two different colors meet? I will obviously be using brushes.
> > Foam for the main colors and a thick liner brush for the black
> > outlines.
>
> Unfeathered edges - the raw edge of the old paint. =A0Imagine a large pai=
nt
> chip missing - the edges of the chip. =A0On a thin coat of paint that edg=
e may
> not be very significant but on a thicker coat it would be very significan=
t.
> You'd want to feather that down to blend it into the wood.

The original paint was lacquer and therefore somewhat transparent. If
you sand it too much the color underneath the color you are sanding
stars to come through. It doesn't chip, so there are no unfeathered
edges to worry about.

> > But as far as sanding *after* I finish re-painting. Camn this be done
> > without having to worry about bleed over?
>
> Bleed over? =A0Don't understand what you mean.

When one color contaminates an adjoining color.

Darren Harris
Staten Island, New York.

S

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 12:33 PM

On Sunday, December 2, 2012 12:50:47 AM UTC-5, Ed Pawlowski wrote:
> Paining over lacquer with latex is just repainting, not restoration.

I'm not sure what you mean by that. As long as the surface is smooth the th=
ree different color matched latex paints I have, which are actually primer =
and paint in one, will be used on the entire side which was actually origin=
ally stenciled and sprayed. The base/background color, the second and then =
third color, followed lastly by the black outlines.

In fact, the most difficult part is the black outlines, which is really all=
I need to get right.

On Sunday, December 2, 2012 6:59:47 AM UTC-5, Mike Marlow wrote:
> No need to sand off old paint as long as it is adhearing well. Sand to=
=20
> develop tooth, and to feather out any edges, as any edges will show throu=
gh=20
> the primer, and your finish paint. You do not need a very coarse paper t=
o=20
> develop tooth - 400 grit is plenty coarse enough.Blending edges may likel=
y=20
> require a coarser paper though. Since you are using latex, which is as=
=20
> thick as snot, you probably won't have to blend the edges down to a level=
=20
> you cannot feel, but you likewise will not want to leave unfeathered edge=
s=20
> either.

Ok. I'm not 100 sure what you mean by "unfeathered edges". Is that were two=
different colors meet? I will obviously be using brushes. Foam for the mai=
n colors and a thick liner brush for the black outlines.=20

On Sunday, December 2, 2012 9:11:10 AM UTC-5, Larry Jaques wrote:
> Lacquer is much, much thinner than latex, so you'll have lines at the
> edges. Those can be sanded flatter (with a dual-action sander, or DA)
> once the latex hardens completely. Then you can put a clear covercoat
> over it all for a better look. I doubt you'll be able to match the
> colors and glosses, so plan on painting the entire panel once you
> start. Paint usually won't stick well to vinyl, either, so I'd avoid
> that.

Ok. There is no vinyl involved in this project.

The paint I'm using is Valspar Interior Semi-Gloss, which is a paint and pr=
imer in one. I did ask for something to clear coat it with and was directed=
to get Valspar Clear Gloss Premium Enamel in a rattle can, which is suppos=
ed to seal and increase durability.

On Sunday, December 2, 2012 1:08:17 PM UTC-5, -MIKE- wrote:
> If whatever you're applying on top will stick to what's beneath it, you
>=20
> don't need to sand down to wood. With many woods, whatever is already on
> the surface is better to paint over than bare wood, anyway.

In a question involving a different but similar project, *priming* over a c=
lean, lightly sanded surface that still has paint is no problem, correct?

> Smooth is relative with paint, as well. I can't tell you how many times
> I've sanded a drywall patch "perfectly smooth" only to see the borders
> after painting. If there's any texture or artwork on top, it often hides
> those imperfections. But a single color, smooth topcoat will often show
> them.
>=20
>=20
>=20
> The solution might be building up a couple layers of primer with flat
> sanding in between coats. Good auto-body guys are maters of this.

I don't want to lose the original artwork completely, since it will be my g=
uide when re-painting.

But as far as sanding *after* I finish re-painting. Camn this be done witho=
ut having to worry about bleed over?

Thanks a lot.

Darren Harris
Staten Island, New York.

LJ

Larry Jaques

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 6:11 AM

On Sat, 1 Dec 2012 21:34:47 -0800 (PST), [email protected]
wrote:

>I was curious as to how much sanding is usually necessary before priming.
>
>Is it normal to sand old or even relatively new paint completely off before priming, or just enough so that the primer adheres?

Just enough to give it tooth for the primer to adhere, unless there is
paint flaking off. I'd sand all the flaky paint down and off the
cabinet. Sanding is usually done to flatten the piece for painting.
The glossier the paint, the flatter it has to be without showing the
blemishes.


>I ask because I'm restoring some old artwork on a plywood cabinet, and if I don't sand it off completely it would be easier to restore the art by masking and going over it with each of the three or four colors originally used rather than to have to start from scratch.
>
>The artwork was originally done in lacquer paint, however the paint I'm using to restore it is latex.

Lacquer is much, much thinner than latex, so you'll have lines at the
edges. Those can be sanded flatter (with a dual-action sander, or DA)
once the latex hardens completely. Then you can put a clear covercoat
over it all for a better look. I doubt you'll be able to match the
colors and glosses, so plan on painting the entire panel once you
start. Paint usually won't stick well to vinyl, either, so I'd avoid
that.

--
Happiness lies in the joy of achievement and the thrill of creative effort.
-- Franklin D. Roosevelt

EP

Ed Pawlowski

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 12:50 AM

On Sat, 1 Dec 2012 21:34:47 -0800 (PST), [email protected]
wrote:

>I was curious as to how much sanding is usually necessary before priming.
>
>Is it normal to sand old or even relatively new paint completely off before priming, or just enough so that the primer adheres?
>
>I ask because I'm restoring some old artwork on a plywood cabinet, and if I don't sand it off completely it would be easier to restore the art by masking and going over it with each of the three or four colors originally used rather than to have to start from scratch.
>
>The artwork was originally done in lacquer paint, however the paint I'm using to restore it is latex.
>
>Thanks.
>
>Darren Harris
>Staten Island, New York.


You want to take off enough to get a smooth coat of primer. It does
not have to be bare wood.

Paining over lacquer with latex is just repainting, not restoration.

MM

"Mike Marlow"

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 6:59 AM

[email protected] wrote:
> I was curious as to how much sanding is usually necessary before
> priming.
>
> Is it normal to sand old or even relatively new paint completely off
> before priming, or just enough so that the primer adheres?
>
> I ask because I'm restoring some old artwork on a plywood cabinet,
> and if I don't sand it off completely it would be easier to restore
> the art by masking and going over it with each of the three or four
> colors originally used rather than to have to start from scratch.
>
> The artwork was originally done in lacquer paint, however the paint
> I'm using to restore it is latex.
>

No need to sand off old paint as long as it is adhearing well. Sand to
develop tooth, and to feather out any edges, as any edges will show through
the primer, and your finish paint. You do not need a very coarse paper to
develop tooth - 400 grit is plenty coarse enough.Blending edges may likely
require a coarser paper though. Since you are using latex, which is as
thick as snot, you probably won't have to blend the edges down to a level
you cannot feel, but you likewise will not want to leave unfeathered edges
either.

--

-Mike-
[email protected]

Mm

-MIKE-

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 12:08 PM

On 12/1/12 11:34 PM, [email protected] wrote:
> I was curious as to how much sanding is usually necessary before
> priming.
>
> Is it normal to sand old or even relatively new paint completely off
> before priming, or just enough so that the primer adheres?
>
> I ask because I'm restoring some old artwork on a plywood cabinet,
> and if I don't sand it off completely it would be easier to restore
> the art by masking and going over it with each of the three or four
> colors originally used rather than to have to start from scratch.
>
> The artwork was originally done in lacquer paint, however the paint
> I'm using to restore it is latex.
>
> Thanks.
>
> Darren Harris Staten Island, New York.
>

If whatever you're applying on top will stick to what's beneath it, you
don't need to sand down to wood. With many woods, whatever is already on
the surface is better to paint over than bare wood, anyway.

Smooth is relative with paint, as well. I can't tell you how many times
I've sanded a drywall patch "perfectly smooth" only to see the borders
after painting. If there's any texture or artwork on top, it often hides
those imperfections. But a single color, smooth topcoat will often show
them.

The solution might be building up a couple layers of primer with flat
sanding in between coats. Good auto-body guys are maters of this.


--

-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

MM

"Mike Marlow"

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 3:40 PM

[email protected] wrote:

>
> Ok. I'm not 100 sure what you mean by "unfeathered edges". Is that
> were two different colors meet? I will obviously be using brushes.
> Foam for the main colors and a thick liner brush for the black
> outlines.
>

Unfeathered edges - the raw edge of the old paint. Imagine a large paint
chip missing - the edges of the chip. On a thin coat of paint that edge may
not be very significant but on a thicker coat it would be very significant.
You'd want to feather that down to blend it into the wood.

>
> But as far as sanding *after* I finish re-painting. Camn this be done
> without having to worry about bleed over?
>

Bleed over? Don't understand what you mean.

--

-Mike-
[email protected]

Mm

-MIKE-

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 5:34 PM

On 12/2/12 2:33 PM, [email protected] wrote:
> On Sunday, December 2, 2012 1:08:17 PM UTC-5, -MIKE- wrote:
>> If whatever you're applying on top will stick to what's beneath it, you
>>
>> don't need to sand down to wood. With many woods, whatever is already on
>> the surface is better to paint over than bare wood, anyway.
>
> In a question involving a different but similar project, *priming* over a clean, lightly sanded surface that still has paint is no problem, correct?
>

Not that I know of. Priming over a surface that has different,
contracting colors can help keep the top color even.


>> Smooth is relative with paint, as well. I can't tell you how many times
>> I've sanded a drywall patch "perfectly smooth" only to see the borders
>> after painting. If there's any texture or artwork on top, it often hides
>> those imperfections. But a single color, smooth topcoat will often show
>> them.
>>
>>
>>
>> The solution might be building up a couple layers of primer with flat
>> sanding in between coats. Good auto-body guys are maters of this.
>
> I don't want to lose the original artwork completely, since it will be my guide when re-painting.
>
> But as far as sanding *after* I finish re-painting. Camn this be done without having to worry about bleed over?
>

I don't know what "bleed over" means, and I'm certainly no paint expert.
But I would never sand the final, finish coat of paint. Maybe some do.


--

-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

MM

"Mike Marlow"

in reply to [email protected] on 01/12/2012 9:34 PM

04/12/2012 9:54 PM

Searcher7 wrote:
> On Dec 2, 3:40 pm, "Mike Marlow" <[email protected]> wrote:
>> [email protected] wrote:
>>
>>> Ok. I'm not 100 sure what you mean by "unfeathered edges". Is that
>>> were two different colors meet? I will obviously be using brushes.
>>> Foam for the main colors and a thick liner brush for the black
>>> outlines.
>>
>> Unfeathered edges - the raw edge of the old paint. Imagine a large
>> paint chip missing - the edges of the chip. On a thin coat of paint
>> that edge may not be very significant but on a thicker coat it would
>> be very significant. You'd want to feather that down to blend it
>> into the wood.
>
> The original paint was lacquer and therefore somewhat transparent. If
> you sand it too much the color underneath the color you are sanding
> stars to come through. It doesn't chip, so there are no unfeathered
> edges to worry about.
>
>>> But as far as sanding *after* I finish re-painting. Camn this be
>>> done without having to worry about bleed over?
>>
>> Bleed over? Don't understand what you mean.
>
> When one color contaminates an adjoining color.
>

Got it. You meant bleed through. As for sanding after re-painting... you
can if you use a fine grit and are careful how much you sand. Even a very
fine grit will cut through a top coat at some point, exposing the underlying
coats. That's not really bleed through though. Bleed through is when the
underlying colors are still (partially) visible through your undisturbed top
coat. Think - not enough top coat.

I'm sorry to have to ask - if you've already said why, but why is it that
you are thinking about sanding your finished top coat? There can indeed be
good reasons to do this, but it also depends on the paint in question. Not
all paints will shine if knocked down with sandpaper. Don't want to answer
your question incorrectly and steer you wrong.

--

-Mike-
[email protected]

EP

Ed Pawlowski

in reply to [email protected] on 01/12/2012 9:34 PM

02/12/2012 4:58 PM

On Sun, 2 Dec 2012 12:33:34 -0800 (PST), [email protected]
wrote:

>On Sunday, December 2, 2012 12:50:47 AM UTC-5, Ed Pawlowski wrote:
>> Painting over lacquer with latex is just repainting, not restoration.
>
>I'm not sure what you mean by that. As long as the surface is smooth the three different color matched latex paints I have, which are actually primer and paint in one, will be used on the entire side which was actually originally stenciled and sprayed. The base/background color, the second and then third color, followed lastly by the black outlines.
>

When you "restore" something, you bring it back to original condition.
If you have a '55 Chevy and replace the chrome on the bumper with
silver paint, it is just painted, not restored. Replacing lacquer
with latex is not a restoration.


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