Moisture Readings on a Stripped Door

Stripper residue may affect moisture-meter readings on woodwork. February 13, 2006

How do we get the moisture down in an exterior door that was stripped with Big E and then neutralized with vinegar (to lower the pH) over 3 months ago? We are trying to rectify someone else’s problem. It was initially stripped with Peel Away 5 years ago, and it immediately started breaking down and moisture got in the grain and raised it badly. We have turned the heat up over the weekend and tried everything. The exterior side is reading 11 to 18/19 and the interior side is 9/10. Does anyone have any suggestions?

Forum Responses
(Finishing Forum)
From contributor A:
The best case would be to remove the door to an environment where you can dry it out, maybe a heated room of some sort. Cover your door opening with a tarp for a day or so - depending on your neighborhood of course!

From the original questioner:
The doors have been inside for over 3 months.

From contributor B:
Unless you're in a very dry climate, that's about average for wood that's not in a climate controlled environment of 50% humidity or less. At our shop, fresh kiln dried lumber with an average MC of 7% goes back to about 10-12% in two or three weeks. Summertime is worse, especially with 90% humidity. If it's humid where you're located, the MC may increase when it's hung again. Air movement will help it dry some.

From the original questioner:
Has anyone ever had luck using *Damp Rid* - the little quart containers that contain moisture eating crystals? We were going to wrap it in plastic and let it sit over night and see if that pulls the moisture out. Do you think that could harm the doors? They are 1850's 4" thick church doors. The interior side is fine it is the exterior that we can't get the moisture out of.

From contributor C:
If the door has been inside for several weeks, the true reading is that seen on the interior surface. I assume that only the exterior surface was stripped? The problem with moisture meters is that they measure the electrical resistance of the timber between the prongs - the more moisture, the lower the resistance. Now cast your minds back to high school, where you could make electricity pass through water more easily by adding salt. What this door now has on the outer face is a concentration of sodium acetate, the resulting salt from the reaction of sodium hydroxide with acetic acid (vinegar). Basically, this door is bone dry and ready for coating, but you may get some salt efflorescence on the exterior face as the salts leach out. Use a vapor permeable finish externally, otherwise the salts will attempt to push a non-permeable coating off.