Friday, March 22, 2013

A Word About Moisture Meters

From my work on a previous lighthouse I know the problems with moisture metering wood that has been exposed to salt water.  On this first lighthouse I was hired to restore an existing transom and build a new door.  During the restoration of the transom I received very weird numbers from my moisture meter.  After some digging around on the net I found the reason why, the salt in the wood effects the transmission between the two pins therefore giving an inaccurate reading. 




The day I went out to Heceta Head lighthouse to start the prep for the painting of the watchtower window frames I came up against a real problem.  My moisture meter was reading at the maximum number, 95.8%.  Even though I couldn't rely on the percentage number I knew all the wood was soaking wet from the feel and because water pooled around the pins when I inserted them into the wood.  And this was the middle of summer.  




After a call to Benjamin Moore I learned that they won't warranty their paint coats unless the wood substrate was at 11% moisture or less.  I knew that drastic measures would have to be taken if I was going to get a paint coat that was to last past the first six months.
First off, I called my moisture meter company to get some advice.  It was the best thing I ever did.  I found out the Lignomat moisture meters that I use are assembled and designed in Portland.  The owner of the company invited me to come to her workshop where I watched as she assembled my new moisture meter.  She instructed me on how I can monitor the wood and gage when the moisture content would be close to the 11%.  

First thing I had to do was remove the frames from the openings which is something I had not wanted to do when I started the project.  I have learned from experience that they often don't go back in as easily as they come out.  But do this I must.  
Second, I would have to take a moisture reading every other day once they were in Portland.  I would have to graph each reading and when the numbers had stopped dropping and leveled off I would be close to 11% moisture for Portland in the summer.  

Once levels were stable, then I could start the repair process.






2 comments:

Ralph Johnson said...

That was an amazing tool, what are other uses for that instrument?
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Hardware said...

Has anyone ever gone shopping for a specific tool and left the hardware store with something that they had never seen before? This is one of my problems or pleasures and I seem to do it way too often. The best way is to search online before going out to the store and either purchase online or send someone to pick it up.
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