Matching Fresh Poplar to a Stripped Old Poplar Door

Here's a discussion about what stripping solution does to Poplar, and about matching that appearance in fresh new wood.July 16, 2012

My client has some old French doors that were painted, dip stripped, and returned to the job site. They are over 100 years old and made in solid popular and now have a uniform patina to them almost faded to a brown. I had to do some repair work to them with new popular which has green color in it. How can I get the new popular to look like the old popular color? When I sanded in the repair flush the old color turned to match the new green so I assume the stripper chemical is what will change it back.

Forum Responses
(Finishing Forum)
From contributor R:
Just a hunch but it might be a lye. Itís commonly used in dip tanks.

From the original questioner:
Where can I find it and can you suggest a mix I can start testing samples with?

From contributor C:
Usually an oxalic acid wash is used after hot tank stripping to eliminate discolorations caused by the stripper. It could be that they didn't do that. Also, old poplar will naturally darken over time.

From contributor T:
Try Sodium Hydroxide in a 10% solution of water. Straight (Lye) can burn the wood so start with a milder solution. Oxalic Acid with neutralize the solution. Be careful when working with caustic solutions as they can cause burns to the skin. I have the scars to prove it.

From contributor H:
This is one of the main reasons that there are not a lot of hot tanks any more (that and the power bill to keep a hot tank fired up 24/7). Chances are that they did neutralize the lye solution. I would sand the wood down with 120 then oxalic everything. Oxalic will not work if it cannot get into the cellular fibers of the wood. That includes leftover paint, or even hand oils. Use oxalic and water and stick them out in the sun to dry, then rinse down with clean water. The off coloration in your new wood can be reduced with a wash of George Franks "Witches Brew" (vinegar and iron filings). I have had a bottle of the stuff brewing for the past 25 years. Strain and dilute with water and use it like you would a stain. Mix a lighter color than you think then hit it with a heat gun or a touch and it will dry and bloom the iron to the right color.

From contributor I:
How much time do you have? The green goes away pretty quickly with direct sun exposure. If you take them outside after the repair for a week of direct sun, they might be pretty close.