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View Full Version : Brushing on poly... but the stain comes off on the brush



Tom Hammond
04-22-2010, 1:23 PM
So... I build a beautiful oak bookcase and stain it with MinWax red oak stain, and it looks great. Then, I begin to brush on MinWax polyurethane. The stain becomes streaky and I notice that the brush is discoloring to the color of the stain. Cleaned the brush, and notice that the stain is actually coming right off the wood.

I have two things to say:
1. AAAAARRRRRGGGHHHHHHHH !!!!!
2. Any help is greatly appreciated.

Prashun Patel
04-22-2010, 1:33 PM
This happened to me back in the day too - with those very same 2 products.

The problem is that the stain is not fully dry. The solvent in the stain and the poly are similar and will dissolve each other b4 fully dry.

Dave Gaul
04-22-2010, 1:44 PM
Tom,

I have been trying to learn as much as possible about finishing, as it is my weakest skill, so I am hoping this reply shows that I have learned something, if not, someone will correct me!

Red Oak has tannins, which can cause the stain to seep back out of the wood.. I am guessing that is what is happening here... When you stain, dye or oil wood with high tannins, you have to go back and wipe off any excess that "bleeds" out, and you should check often for the first hour or so after applying...

Also, maybe just your preference, but I don't see why you would apply Red Oak stain to Red Oak...

Rob Young
04-22-2010, 1:49 PM
Seal the stain with a spit coat of de-waxed blonde shellac. Say around a 1# cut. Then put on the poly.

Alternatively, you can build up some depth to the finish with the shellac (two, three, four coats at #1 to 2# - exact cut isn't terribly critical) then seal with the poly. More layers of shellac, fewer of the poly. Shellac goes on fast, drys fast, cleans up and touches up fast.

Prashun Patel
04-22-2010, 2:04 PM
If you don't want to muck around with shellac, then yr easiest solution is just let it dry for a few more days at room temp.

Shellac barrier coats are easily applied with spray equipment. But with a brush, you risk lifting the stain a little still (alcohol is a pretty good solvent in its own right) - DAMHIKT.

Scott Holmes
04-22-2010, 7:16 PM
Dave,

Partially correct:

Tannins cause Oak to make stuff with iron turn black. The large open pores of red oak suck up a lot of stain then as it starts to dry, it pushes back out of the pore, many call this weeping, seeping and most often bleedback.

Barrier coat of some type is the easy fix. Shellac is my choice, most times. Most any sprayed coat of finish will work.

Tom,

I don't like to make assumptions ... Did you wipe the excess stain off after 5-15 minutes and continue to wipe any bleedback? If, not then the main cause is too much stain left on the wood.

Tom Hammond
04-23-2010, 11:06 AM
Tom, I don't like to make assumptions ... Did you wipe the excess stain off after 5-15 minutes and continue to wipe any bleedback? If, not then the main cause is too much stain left on the wood.

I do wipe the stain off after about 15-20 minutes. Too much stain... hmmmm.... that's an interesting theory. I'll try more wiping.

Thanks to all ! I appreciate the input.

ARGH... I NEED A SPRAY BOOTH !!!!

Howard Acheson
04-23-2010, 2:43 PM
First, did you follow the label directions regarding applying the stain, letting it set for 15 minutes and then thoroughly wiping off the excess? Wiping off the excess is a key step.

Second, let the stain fully dry for at least 24 hours and 48 is better.

Third, only gently apply your initial coat of clear. The stain contains a small amount of varnish that holds the pigment onto the surface. When you apply a top coat too aggressively, you can dislodge some the the pigment and that is what you are seeing. Even with a gentle application, some pigment may come off but it should not affect the finish. Second and subsequent coats should apply with no color transfer.

Julie Rose
04-23-2010, 8:22 PM
I have had the same problem with pine. The only solution is to wait longer, what it says for wait time on the can is often not enough for the stain to really be completely dry. The application of poly seems to lift the stain off the wood. Wait an extra day or two and try again.

~Julie~

Cameron Reddy
04-23-2010, 8:42 PM
I'm having a similar problem and intend to solve it with an HVLP spraying system from Jeff Jewett.

Cameron

Scott Holmes
04-23-2010, 10:21 PM
Julie and Cameron,

It sounds as if you leave more stain on the project than is recommended. Stain can't be applied as paint you must wipe the excess off in 5-15 minutes. Dry time should be OK then. Cameron, spraying will only allow you to go faster; it can't make you a finish pro. Practice. Practice. Practice. Practice.

Joe Shinall
04-23-2010, 10:42 PM
I too have had this same problem with Red oak, minwax stain, and minwax poly. I do believe Scott is totally right by telling you guys too much stain. I built a jewelry box and could not get the poly to take after the stain. Same thing was happening, pulling up the stain from the oak.

I built a second one a few weeks later and went very sparingly with the stain and wiped wiped and wiped some more. Poly went on perfect and clean afterward.

Wish I would have seen Mr. Holmes post before I did that first one.

Scott Holmes
04-23-2010, 10:51 PM
Joe, no need to be so formal; Mr Holmes is my dad. :)

Dave Gaul
04-28-2010, 1:04 PM
Dave,

Partially correct:

Tannins cause Oak to make stuff with iron turn black. The large open pores of red oak suck up a lot of stain then as it starts to dry, it pushes back out of the pore, many call this weeping, seeping and most often bleedback.

Barrier coat of some type is the easy fix. Shellac is my choice, most times. Most any sprayed coat of finish will work.

Scott, thanks for clarifying, but I wanna make sure I got it.. Tannins don't affect the weeping/seeping/bleedback?
And you are saying any sprayed finish will work as a barrier coat? So sprayed laquer would work as a barrier coat on porous woods (Although I'm convince the Shellac IS the best barrier coat from my research...)?

Scott Holmes
04-28-2010, 7:08 PM
The large open pores in red oak are what cause it to "bleedback" stains and finish.

When I said "most any sprayed finish" I should have said "that most any sprayed finish will seal the stain in for you, so, you can brush the next coat."


I don't think it's a good practice to go mixing several different types of finishes.

Shellac is close to a "universal" sealer. Most finishes have no problem sticking to de-waxed shellac and shellac will even stick to Teflon.

Dave Gaul
04-29-2010, 9:12 AM
Ok.. Got it!

I have learned that Shellac will stick to just about anything, sprayed shellac on my last project, and it stuck very well to EVERYTHING it landed on!!!

I don't mix different types of finishes, but I was very interested in learing how these things work!

Ok, I'm done hijacking this thread! Thanks again!!!