Replies

1. 
   Gretchen | Sep 16, 2009 02:13pm | #1

   Bleach. Surely it isn't under the finish.

   Gretchen
1. 
   actuary | Sep 16, 2009 03:02pm | #2

   I know bleach kills mildew but what does it do to the varnish?

1. 
   SteveSchoene | Sep 16, 2009 03:26pm | #3

   How is the surface of the varnish?  Still glossy, unbroken, not crazed?  Does the black appear to be on the surface, or under the varnish on the wood?  Any chance for a picture? 

   Bleach should have no effect on the varnish, certainly not for the relatively brief period you will leave it on.  Mildew kills varnish.   But on a solid, unbroken varnish surface I'd be surprised that mildew wouldn't scrub off, even without bleach. 

   Edited 9/16/2009 8:32 am ET by SteveSchoene

1. 
   forestgirl | Sep 18, 2009 04:22am | #4

   "Bleach should have no effect on the varnish, certainly not for the relatively brief period you will leave it on."  What concentration would you recommend, Steve?  I'm assuming not full strength?forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

1. 
   SteveSchoene | Sep 18, 2009 05:23am | #5

   I've general approached such things very scientifically, the few times I've had to do it.  I put some water in a plastic bucket, then I pour in a few good glugs of bleach.  I usually ruin a T-shirt (or rather, I convert it for wear while finishing). 

2. 
   forestgirl | Sep 18, 2009 05:30am | #6

   OK, Steve, got it!  Seriously, though, I sometimes have visions of someone pouring it on straight.  Not!  Doesn't take much to kill what ails, LOL.

   BTW, I start with the same finely-tuned proportional measurements that  you do.  But I modify slightly depending on the alignment of the stars and the phase of the moon.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

   Edited 9/17/2009 10:31 pm by forestgirl

3. 
   HowardAcheson | Sep 18, 2009 08:14pm | #7

   If forced to give an answer I generally quote 1:10 or 1:12 fresh Clorox to water. Say it authoritatively and walk away.Howie.........

4. 
   mrbird90 | Sep 20, 2009 02:35am | #8

   Most sources say that one part bleach to three parts water with a dash of soap to act as a wetting agent. This is what I use all summer as black mildew forms on my white painted tables on our deck. I have used it for years with no problems on the painted surfaces. I also do my deck in spots where the black or greem mold starts to form on the deck surfaces.

   Edited 9/19/2009 7:35 pm ET by mrbird90

5. 
   Gretchen | Sep 20, 2009 03:27pm | #9

   I have been known to just put some bleach on a cloth and wipe away!  ;o)Gretchen

2. 
   actuary | Oct 27, 2009 03:55am | #12

   I finally got to dealing with mildew issue and tried bleach in various diluted amounts, and even at 100% bleach the mildew remained--although it's much lighter in color. Any ideas about something stronger?

1. 
   Blackwill | Oct 27, 2009 08:17pm | #13

   Try milk. It works on plants with powdery mildew.

2. 
   SteveSchoene | Oct 27, 2009 11:34pm | #14

   The bleach has undoubtedly killed the mildew, but you will still have to scrub off the "dirt" that it creates.  A stiff brush, and a drop or two of liquid dishwashing soap just to break the surface tension of the water.   

2. 
   Beckum | Sep 27, 2009 07:48pm | #10

   I have a silly question .... Did you seal the bottoms of the legs? The mildew could be coming up through the end grain. If so, you may have to put your bleach water into cups and soak the bottoms of the legs in it for a while. Then, of course, let it dry forever before you seal them up. I've had to do that repair a couple of times over the years. Sometimes people forget that when they are doing outside furniture. Heat lamps will dry out the legs after a couple of days, just turn the piece upside down so the heat will carry the moisture out of the wood and not deeper into it.

1. 
   actuary | Oct 12, 2009 12:25am | #11

   not a silly question but in fact I did seal the leg bottoms. I also attached plastic cups or protectors on the leg bottoms so the table is raised about 1/4" from the patio and won't sit in any rainwater. In any case, the mildew is only on the table top.