Fixing mold issue on live edge slab
#4
I built a bar from locally sourced lumber many months ago.  I'm having an issue with the bar top.  There wasn't mold on the edges after I finished it many months ago (or before), but it is constantly reappearing even after wiping it away with paper towels or disinfectant wipes.

The locals do not kiln dry these slabs and they form them into tabletops very soon after slabbing them.  Apparently, the wood is very stable and it seems to be.  There were live borers of some kind in the slab so I treated it with a liquid borax solution and then wrapped the slab in black trash bags, left it in the sun for a week (turning midday), and ensured with an IR gun that it was above 135deg for many hours which was easy to do with the sun we get here.  I have not seen any new evidence of borers.  It's finished all over with several coats of polyurethane.

The bar lives outside but in a covered patio and never gets rained on. We are also emerging from rainy season and it's getting dry again.

Just let it go and let it dry further, or is there something I can do to kill it off?  I could sand back the outer edge to fresh wood and re-seal, but the other edge is scribed to another portion of the bar and I don't want to make any adjustments.

Thanks,
Paul



   



   
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#5
Wood moisture content between [b]0% and about 28%[/b] is dependent upon the relative humidity (RH) of the air. As the air’s RH increases, so does the moisture content of any wood exposed to the air. Wood exposed to air with a RH of about 90% will reach a Wood Moisture Content of about 20%. Above 90% RH or 20% WMC, mold can grow on the wood.

Wood Moisture Content - RLC Engineering, LLC
www.rlcengineering.com/wood-moisture-content/


Your wood must still be really wet inside and it's unlikely you'll be able to stop the mold for long until it dries below 20% moisture.  You can hasten the drying by removing the finish and then drying it, slowly, down to whatever the typical indoor moisture content is for wood where you live. 

John
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#6
(11-08-2021, 03:28 PM)atgcpaul Wrote: Just let it go and let it dry further, or is there something I can do to kill it off?  I could sand back the outer edge to fresh wood and re-seal, but the other edge is scribed to another portion of the bar and I don't want to make any adjustments.

Thanks,
Paul

Not sure if you can get this where you live or if it will work for your situation but it worked for me.

https://www.amazon.com/Siamons-Internati...1645&psc=1

I had a bunch of alder I got that had been stored in a barn for who knows how long.  It had mold in a lot of places.  I treated it with this and then sanded off the mold stains.  The mold did not return but I live in a dry climate.
A carpenter's house is never done.
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