Getting the Red Out

Tips and advice for neutralizing a red stain under urethane on mahogany, using "opposite-color" theory. August 9, 2005

There's a lot of mahogany out there, and most of it gets finished with various forms of red mahogany stain. But the doors already have been top-coated, so the options become minimized. I don’t know ow many times I’ve had to explain that you just can't stain over polyurethane finish

Currently I have a very difficult customer, who doesn't like their red, and also doesn't like the “no stain over urethane” explanation. I just did a sample with my usual trick of taking Sikkens Cetol 23 dark oak and I put a couple coats over the previous top coat after a complete sanding.

The folks didn't think it took enough red out, so I mixed some of the Sikkens with a custom dark brown stain and they somewhat liked the effect, until I told them I'd only give them a one year workmanship guarantee because I was adding too much stain to the urethane which will effect long term adhesion to the previous coat.

So here I am, wondering if I should bother to go to emergency plan b, which would be adding green and blue tints to a urethane and laying it on the red to make a brown. My past experience with this has been a brown, but one with a blue or green hue.

My other emergency plan which has worked in the past is raw umber, it is the answer when all else fails. Add it to urethane, and it pretty much neutralizes anything, but the resulting color is not spectacular. Does anyone have any ideas?

Forum Responses
(Finishing Forum)
From contributor J:
I would suggest that you take a small amount of green - which is the opposite color of red and add it to some of your stain or urethane. Wipe or spray it over the too red mahogany. Pure green is the most effective way to neutralize red. Raw umber - which has a greenish undertone, will work, but you may need too much colorant, and then you're back to your original problem.

From contributor M:
Contributor J is right, mixing red and green will give you many different colors of brown, and this will depend on the amount of each color you use. The green will take out the red, and kick it back to brown. You then may want to try adjusting the brown.

From contributor E:
I am currently dealing with the same problem. I stripped a table to discover a cherry veneer table and I bleached the cherry to kill the red. The customer wanted the table to be a green color with the entire grain clarity showing. There can’t be a muddy appearance what so ever.

I decide to go with a NGR raw umber with a little raw sienna. I sealed that in place and it was really red still. I then had to mix up a batch of green lacquer to kill the red. I added green mixol to my lacquer. I applied two coats at two mills. I then made a dye toner - raw umber with lacquer.

I sealed that in place and then applied another coat of toner. I decided to get out the sheen meter and check the sheen of the sample board. It was 61 and my table was 91.I killed the sheen on my table, and there was the color Maybe you could try to knock down the sheen. A lower sheen level hides a lot, and I found in my case it even knocks down the red.

From contributor O:
The use of raw umber will only serve to darken your color. The use of phthalo green to oppose the red is the way to go. The addition of yellow to brighten the green helps tremendously in this area. Make sure to make samples.

From contributor C:
Contributor H is right about the phthalo green. It is a very powerful tinter though – make sure to use it in very small amounts. Polyurethanes are able to perform well with a wide range of film thicknesses, so you can normally over-glaze as much as you'd like to (or need to). Just do not put too much tinter in any one coat.

I often approach projects like this with a green tinted glaze that readjusts the overall color cast, and then I use a light tint of umber (raw or burnt depending on which hue shift is desirable) in another topcoat. This will keep you from seeing the greenish cast that can appear at certain angles otherwise. It is also easier to get the tint that you desire when you approach it in two or more steps as each coat represents a new opportunity to fine tune the color.

I will sometimes use Star waterborne poly for quick adjustments like this as a lightly tinted solution can be made up and numerous coats applied within a very short time gently approaching the desired look in small, but quick steps. I use Star Hydrogold (wipe on) for this. This stuff has amazing durability. I put some on some marble tile inserts in a commercial showroom and it has been untouched by the heavy traffic there.