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Polyurethane pulling up stain

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Forum topic by brianl posted 03-15-2010 05:15 AM 12285 views 1 time favorited 11 replies Add to Favorites Watch
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brianl

108 posts in 2546 days


03-15-2010 05:15 AM

Topic tags/keywords: oak finishing polyurethane

On a recent project (red oak) I noticed that then I tried to brush on a coat of polyurethane a decent amount of stain lifted out of the wood. The color of the piece changed quite a bit because of this. Is this because of bad stain? Or is it because of the finish not being sealed? Should I seal the stain with a spit coat of shellac first (As Scott Bryan mentions)? Would that prevent the smearing and stain transfer? Would I just brush on the shellac?

Thanks!
Brian

-- Brian - Belmont, Massachusetts


11 replies so far

View Scott Bryan's profile

Scott Bryan

27251 posts in 3287 days


#1 posted 03-15-2010 12:12 PM

Brian, stain lift-off is not the result of a bad stain but it is just a natural process (I am assuming that the stain and poly were similar formulations). Sealing the stained wood with shellac will help with your lift off problem.

-- Challenges are what make life interesting; overcoming them is what makes life meaningful- Joshua Marine

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Julian

880 posts in 2990 days


#2 posted 03-15-2010 12:45 PM

How soon after staining did you apply the finish coat?

-- Julian, Park Forest, IL

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brianl

108 posts in 2546 days


#3 posted 03-15-2010 01:12 PM

The stain and poly were both oil-based. I waited 3 days between stain and poly.

I was pretty mystified when it happened – I’ve never had to deal with this before (that I noticed anyway).

I found a similar discussion at WoodWeb (although they are talking about Water-based over Oil-based).

So applying a thin coat of shellac with a brush should not lift the stain? Should I cut the shellac with anything?

Thanks
Brian

-- Brian - Belmont, Massachusetts

View SKFrog16's profile

SKFrog16

661 posts in 2665 days


#4 posted 03-15-2010 01:51 PM

You should use what is called a spit coat of shellac, 1/2lb cut. This will seal every thing and allow a great finish coat with no lifting.

-- Methods are many,Principles are few.Methods change often,Principles never do.

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rickf16

387 posts in 3046 days


#5 posted 03-15-2010 05:34 PM

Agree with Scott. Had the same problem on my entertainment center. Put the poly on after staining and the stain kinda “smeared” with the poly. Sealed it with shellac and no problemlo!

-- Rick

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wisno

88 posts in 2476 days


#6 posted 03-15-2010 11:30 PM

Yes it is
It a normal situation when you brush your coat. I don’t think the varnish will help.
As long as you brush the coat, the coat will resolves the stain and pull out the stain little bit.
The only way prevent it is, to spray your clear coat either it poly or varnish
Spray gun application in the furniture finishing

Wisno

-- http://www.wisnofurniturefinishing.com/

View Gofor's profile

Gofor

470 posts in 3252 days


#7 posted 03-16-2010 12:03 AM

I haven’t had that problem, but I usually wipe off all excess stain before it dries. With oak, I sometimes have to wipe it a couple times as it seeps out of the large pores.

However, IIRC, Zinsser’s Bulls-Eye Seal Coat is premixed 1/2lb cut dewaxed shellac. The cans should have the mfgr date on them, so don’t buy any pre-mix that is over 6 months old.

Go

-- Go http://ncwoodworker.net/pp/showgallery.php?cat=500&ppuser=730

View Tim29's profile

Tim29

307 posts in 2615 days


#8 posted 03-16-2010 12:15 AM

I have had that same problem. What I have done in the past (after a little bit of crying) is to spray my first coat of poly after staining. brush on my second coat, sand very lightly with at the roughest 180 grit sandpaper or sponge, then brush on 1 or 2 more coats sanding in between coats. for a final buffing I sometimes get the cheap brown paper towels like out of a gas station and rub the final dryed finish with these. it comes out very nice. hope this helps

-- Tim, Nevada MO

View brianl's profile

brianl

108 posts in 2546 days


#9 posted 03-17-2010 03:57 PM

Thanks for all the feedback guys!

I went out and purchased Zinsser's Clear Shellac and some Denatured alcohol solvent. I read that Zinsser’s is a 2lb cut, so I used the chart at shallac.net to get an idea of what a 1/2lb cut is.

I sanded everything back down to bare wood (ultra smooth – 220 grit), restained (wiping away the excess), let dry for 12 hours then I lightly brushed on the shellac solution with a foam brush and let dry. I let it wait 12 hours and then I proceeded to start applying polyurethane – which is in process now. It isn’t as smooth as I wanted, but I am guessing that will come with layers of polyurethane (using 0000 steel wool inbetween layers). The wood was like glass before the shellac.

Thanks again for all your help guys.
Brian

-- Brian - Belmont, Massachusetts

View Bill White's profile

Bill White

4456 posts in 3425 days


#10 posted 03-17-2010 06:06 PM

First:
Ya gotta use SEAL COAT DEWAXED shellac.as a sealer.
Second:
Why are you determined to use poly? Are you thinning the poly?
Bill

-- bill@magraphics.us

View hObOmOnk's profile

hObOmOnk

1381 posts in 3592 days


#11 posted 03-17-2010 06:43 PM

Zinsser also sells shellac in a spray can.
It’s good when you don’t want to touch your stained wood.

-- 温故知新

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