D

08/11/2008 3:48 PM

finishing... can of worms.... I know

I am a newbie woodworker on my second project. The first project I
just used a natural look with a couple of coats of Poly.... no
problem. My newest project is a 24"x24" chest of drawers for my
closet.
Quite a bit bigger, and I'm using it as a test bed for finishing and
joinery and what not. I used a dark stain on the Birch plywood,
turned out nice... even color. The first coat of brush on Satin Poly
that i put on was good. When I went to do a light sanding (240 grit)
on it (as instructed by the can) some of the stain came off. After
the next coat, when sanding, I got some scratches. After that, I
switched to 320 grit and still got scratches. The rest of the coat
looks fine, nice and smooth. I just don't know what I'm doing wrong.
I'm not pressing very hard and at this point have tried different
strokes with the sandpaper (back and forth, circular, one direction,
even tried using a block). Any suggestions, recommendations,
anything???? Cause I'm at my whit's end trying to figure it out on my
own.


This topic has 7 replies

BB

Bored Borg

in reply to [email protected] on 08/11/2008 3:48 PM

09/11/2008 3:54 PM

NEVER START WHAT YOU CAN'T FINI





sorry.... :-)

RC

Robatoy

in reply to [email protected] on 08/11/2008 3:48 PM

08/11/2008 5:53 PM

On Nov 8, 7:24=A0pm, "[email protected]" <[email protected]>
wrote:
> Stop... take a breath.
>
> Most finishing problems are procedural, and can be fixed with the
> right approach.
>
> If you used an oil based stain, a couple of things probably happened.
> (Disregard of you used a water borne color). =A0The stain wasn't 100%
> dry, even though it felt like that to you. =A0When you put the poly on,
> it dissolved the tiny amount of oil in the stain that had not dried
> out. =A0It brought the stain into the poly. =A0When you sanded the poly,
> you sanded off your color. =A0It happens.
>
> Solution: =A0If you want to get the show on the road and are pressed for
> time, stain your piece, the seal with dewaxed sanding sealer. =A0Sand
> lightly, apply poly according to instructions.
>
> If you are not in a huge hurry, you should apply the (oil) stain to
> the piece and let it sit for about a week. =A0Then apply your poly as
> directed.
>
> Regardless of which avenue you choose, make sure your stain is put on
> in light, even coats. =A0If you need to apply more than one coat, wait
> 24 hours between coats so you can see what the wood will actually look
> like with the stain. =A02 - 3 light coats of stain are better than one
> thick heavy one. =A0This allow you to follow the amount of color
> penetration in the different areas of your project and apply more
> colorant as needed.
>
> As a sidebar, I don't sand between coats of poly if I am actually
> doing the finishing as a process. =A0I recoat in 8 - 10 hours, and do
> only a cursory sand for dust nibs. =A0The poly will bite fine into the
> first coat.
>
> But if I have to wait a day or two between coats, I hand sand with 220
> to knock off the sheen. =A0If it is a week before I can coat again, I
> usually wait for about 10 day or more so I can sand more aggressively
> before applying another coat.
>
> Do not swirl or rub your sandpaper; follow the grain in long, even
> strokes with the lightest pressure possible. =A0Your finish is probably
> showing marks due to incorrect technique. =A0Use clean, new paper. =A0Whe=
n
> it feels dull, you should have thrown it away a few minutes ago. =A0If
> the face of the paper clogs with finish, you are sanding too hard, or
> using dull (or cheaply made) paper.
>
> Sanding between coats is insurance for the finish to bite. =A0A green
> finish will be dry to the touch and probably won't mark, but it is
> still quite soft. =A0That's another reason for the marking. =A0Make sure
> you use a block with the paper wrapped around it. =A0I am a big fan of
> the foam sanding pads, and use them as sanding blocks for paper when
> their own grit is gone.
>
> Good luck!
>
> Let us know how it goes.
>
> Robert

I'm sure others feel the same way, but let me thank you with a *tip-of-
the-hat* for your helpful input.
It is a funny thing. But somebody asks a question and a dozen or more
are helped by the answer.
You go into detail and the help is appreciated. Just wanted you to
know that. Thassal.

r (that's the lower case 'r')

nn

in reply to [email protected] on 08/11/2008 3:48 PM

09/11/2008 1:25 AM

On Nov 8, 7:53 pm, Robatoy <[email protected]> wrote:

>
> I'm sure others feel the same way, but let me thank you with a *tip-of-
> the-hat* for your helpful input.
> It is a funny thing. But somebody asks a question and a dozen or more
> are helped by the answer.
> You go into detail and the help is appreciated. Just wanted you to
> know that. Thassal.

Hey.... thanks, Rob. I appreciate the compliment and the feedback.
Sometimes you never know if anyone reads a response, but we all know
how good it feels when you can get someone out of the weeds on their
project. If it helps someone besides the OP, that's even better.

' Preciate it.

Robert

RB

"Rod & Betty Jo"

in reply to [email protected] on 08/11/2008 3:48 PM

19/11/2008 10:05 AM


<[email protected]> wrote in message
news:[email protected]...
> Hey.... thanks, Rob. I appreciate the compliment and the feedback.
> Sometimes you never know if anyone reads a response, but we all know
> how good it feels when you can get someone out of the weeds on their
> project. If it helps someone besides the OP, that's even better.
>
> ' Preciate it.
>
> Robert

Well I for one have certain issues with your posts.....I suppose its
basically okay that whatever you write is a "must read" but it is also a
"must save"......you force me into filling harddrives, organizing
information and even worse making me think about the information you provide
because it is always so worthwhile.....Anyway in the future life would be
much simpler if you would learn "mindless drivel" and cut out all of the
good stuff.........Thanks Rod

PH

Peter Huebner

in reply to [email protected] on 08/11/2008 3:48 PM

10/11/2008 3:59 AM

In article <cd725009-4c52-499d-9320-8e98e9fe7444
@v16g2000prc.googlegroups.com>, [email protected] says...
> I am a newbie woodworker on my second project. The first project I
> just used a natural look with a couple of coats of Poly.... no
> problem. My newest project is a 24"x24" chest of drawers for my
> closet.
> Quite a bit bigger, and I'm using it as a test bed for finishing and
> joinery and what not. I used a dark stain on the Birch plywood,
> turned out nice... even color. The first coat of brush on Satin Poly
> that i put on was good. When I went to do a light sanding (240 grit)
> on it (as instructed by the can) some of the stain came off. After
> the next coat, when sanding, I got some scratches. After that, I
> switched to 320 grit and still got scratches. The rest of the coat
> looks fine, nice and smooth. I just don't know what I'm doing wrong.
> I'm not pressing very hard and at this point have tried different
> strokes with the sandpaper (back and forth, circular, one direction,
> even tried using a block). Any suggestions, recommendations,
> anything???? Cause I'm at my whit's end trying to figure it out on my
> own.
>


I'm going to stay away from talking about stain, since I never use it.

As for sanding poly, I'm pretty much with what Robert said, with some
frills: I usually lightly sand over the first coat of poly because
there's something poking up or feeling gritty on the surface; I use
something between 400 and 600 grit on fairly fresh poly (e.g. less than
2 days old) and I use wet and dry paper and use water as a lubricant.
Wipe with 2 separate cloths before the next coat. That works pretty
well. Other than that, I don't sand between coats unless there's a
compelling reason, I just make sure I recoat around the 12 hour mark
.... works for me.
Once it's dried for 2+ days, you will usually have to sand or the new
coat will not bond properly. Depending on many factors like chemistry,
humidity, ambient temperature ...
Even on older/hardened poly I wouldn't dream of starting below a 320
grit, using wet & dry paper.

With 4,5 or more coats of poly you can work out a lot of scratches and
accidental uneven-ness, like you may later find the brush left a hair on
the finish that you didn't spot in odd lighting, but once you've gone
into your stain or through the veneer that job's probably a re-do from
start. Been there, done that, gone through the veneer on veneered mdf.
Painful. One reason why I prefer to work with solid wood ;-)

You mentioned using a block: a nice smooth & level sanding cork is the
way to go, i.m.o., and a very light touch.

-P.

Bp

"Baron"

in reply to [email protected] on 08/11/2008 3:48 PM

08/11/2008 8:40 PM

<[email protected]> wrote in message
news:cd725009-4c52-499d-9320-8e98e9fe7444@v16g2000prc.googlegroups.com...
>I am a newbie woodworker on my second project. The first project I
> just used a natural look with a couple of coats of Poly.... no
> problem. My newest project is a 24"x24" chest of drawers for my
> closet.
> Quite a bit bigger, and I'm using it as a test bed for finishing and
> joinery and what not. I used a dark stain on the Birch plywood,
> turned out nice... even color. The first coat of brush on Satin Poly
> that i put on was good. When I went to do a light sanding (240 grit)
> on it (as instructed by the can) some of the stain came off. After
> the next coat, when sanding, I got some scratches. After that, I
> switched to 320 grit and still got scratches. The rest of the coat
> looks fine, nice and smooth. I just don't know what I'm doing wrong.
> I'm not pressing very hard and at this point have tried different
> strokes with the sandpaper (back and forth, circular, one direction,
> even tried using a block). Any suggestions, recommendations,
> anything???? Cause I'm at my whit's end trying to figure it out on my
> own.

Hello,

You don't mention the type of stain you were using or how long you let
it dry but I will assume it was completely dry before you put on your first
finish coat. It sounds like you simply sanded a bit too far and started
sanding off the stain.
As far as the scratches go, it sounds like you saw what you should have.
Even brush applied polyurethane will have a very high gloss finish/smooth
surface. It may have dust nibs in it or have drips and sags but it will be
smoother than you expect. Sanding it will start putting down a scratch
pattern that can only be removed with progressively higher grits. Same idea
as polishing compound on a car finish.

Good Luck.

nn

in reply to [email protected] on 08/11/2008 3:48 PM

08/11/2008 4:24 PM

Stop... take a breath.

Most finishing problems are procedural, and can be fixed with the
right approach.

If you used an oil based stain, a couple of things probably happened.
(Disregard of you used a water borne color). The stain wasn't 100%
dry, even though it felt like that to you. When you put the poly on,
it dissolved the tiny amount of oil in the stain that had not dried
out. It brought the stain into the poly. When you sanded the poly,
you sanded off your color. It happens.

Solution: If you want to get the show on the road and are pressed for
time, stain your piece, the seal with dewaxed sanding sealer. Sand
lightly, apply poly according to instructions.

If you are not in a huge hurry, you should apply the (oil) stain to
the piece and let it sit for about a week. Then apply your poly as
directed.

Regardless of which avenue you choose, make sure your stain is put on
in light, even coats. If you need to apply more than one coat, wait
24 hours between coats so you can see what the wood will actually look
like with the stain. 2 - 3 light coats of stain are better than one
thick heavy one. This allow you to follow the amount of color
penetration in the different areas of your project and apply more
colorant as needed.

As a sidebar, I don't sand between coats of poly if I am actually
doing the finishing as a process. I recoat in 8 - 10 hours, and do
only a cursory sand for dust nibs. The poly will bite fine into the
first coat.

But if I have to wait a day or two between coats, I hand sand with 220
to knock off the sheen. If it is a week before I can coat again, I
usually wait for about 10 day or more so I can sand more aggressively
before applying another coat.

Do not swirl or rub your sandpaper; follow the grain in long, even
strokes with the lightest pressure possible. Your finish is probably
showing marks due to incorrect technique. Use clean, new paper. When
it feels dull, you should have thrown it away a few minutes ago. If
the face of the paper clogs with finish, you are sanding too hard, or
using dull (or cheaply made) paper.

Sanding between coats is insurance for the finish to bite. A green
finish will be dry to the touch and probably won't mark, but it is
still quite soft. That's another reason for the marking. Make sure
you use a block with the paper wrapped around it. I am a big fan of
the foam sanding pads, and use them as sanding blocks for paper when
their own grit is gone.

Good luck!

Let us know how it goes.

Robert


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