help. Mold or mildew on unfinished bench top

[Mike Baker 2]

I have been building my first work bench. It is going to be an outdoor bench. Threads here http://www.sawmillcreek.org/showthre...ons&highlight=

and here http://www.sawmillcreek.org/showthre...mentary-Thread.



It rained yesterday and day before. This is not the first time this has happened during the build. I cover it with a tarp to keep the rain off of it. Yesterday morning I went outside and pulled the tarp off, which is a habit of mine. I don't want that tarp to stay on there and hold in moisture, trying to avoid this kind of problem. When I pulled tha tarp, there is black mold all over the top of the bench, and on top of the jaws of my new vise.
I washed it down with dish soap and bleach water, and for good measure, followed that with straight bleach.
I will let that dry, and then go back out with a palm sander and try to sand all of the spots I can see off of the top.
Anyone have any other suggestions?
I plan to seal the whole thing with Thompson's water seal, as soon as it is dry enough. But it is supposed to rain most of the day tomorrow, and will take at least a couple of days for it to dry before I can seal it with Thompson's.
Does anyone know if I seal it with waterseal, that it will stop the mold, or that the mold won't come through that? I am planning to begin an acoustic guitar build, and don't want to risk getting mold on the wood, or bring mold spores into my home and contaminate all of my good wood stock for instrument building.

[Noah Magnuson]

If this is truly going to be an outdoor bench, you should probably rig up a sheet of roofing or lexan to keep it (mostly) dry like a mini shed roof. This will give it constant air flow and keep it dry As far as finishes. Once the wood is dry (as in cured dry), there is little risk of mold when you leave stuff on top of it. Very few finishes really are weatherproof for constant exposure and those that are aren't really desirable for a bench top, but any number of them will protect it from a bit of water now and then and allow it to bead up and prevent mold. I wouldn't worry too much about transferring general mold spores. They are pretty much everywhere already. It is the conditions that allow them to turn into proper mold growth.

[Rick Malakoff]

Hi Mike, look around at the BORG and see if you can find 1.5 inch thick foil backed ridged foam insulation and make a cover for the bench it is light weight and will be easy to put on and take off.
As for the mold bleach is the best, I don't know the properties of Thompson's but I would think any type oil based product would work well.
Rick

[Mike Baker 2]

Hi Mike, look around at the BORG and see if you can find 1.5 inch thick foil backed ridged foam insulation and make a cover for the bench it is light weight and will be easy to put on and take off.
As for the mold bleach is the best, I don't know the properties of Thompson's but I would think any type oil based product would work well.
Rick

That's a great idea, Rick. Thanks.
I assume you are talking basically a bench sized box that will fit over top of the bench.
I hit it with straight bleach. It killed a lot fo the mold, as in it is gone. But there is still some left. We are forcast for rain tonight and tomorrow, but I am not going to cover it with that tarp again. I will let it rain on it; at least it will have plenty of air flow.
I'll hit it again with straight bleach after the weather clears, let that dry, sand the snot out of it, and seal with Thompson's(oil based). I just need two or three days to let it all dry, and a couple of days after I apply the Thompson's to give it time to dry.

[Mike Baker 2]

In the end, judicious use of a hand plane took care of it. I took my 4 and 1/2 and planed until the mold was no more, then poured straight bleach over the entire top again.
I will go down to Lowes and pick up that rigid insulation as soon as my wallet allows.
Hopefully, there will not be a repeat of this, but if there is, I'll plane it off before I seal the wood.