Replies

1. 
   jackplane | Jan 11, 2005 05:30pm | #1

   Yes, regular bleach will lighten it. Be sure to wash off with baking soda or another antacid.

1. 
   UncleDunc | Jan 12, 2005 02:26am | #3

   Chlorine bleach is not acidic. Soda water wouldn't hurt anything, but it's not necessary.

1. 
   jackplane | Jan 12, 2005 04:49pm | #5

   Chlorine bleach is indeed acidic. Read the label. It is hypochloric acid. Baking soda neutralizes this to prevent interference with any finish.

1. 
   UncleDunc | Jan 12, 2005 05:55pm | #6

   My mistake. What misled me is that the directions on the bleach bottle for dealing with spills don't mention soda. They just recommend flushing with plenty of water. (The solution to pollution is dilution.) Why is soda better than rinsing? Would neutralizing bleach with soda liberate free chlorine?

1. 
   jackplane | Jan 12, 2005 07:06pm | #7

   Rinsing would also work. Soda causes an acid/base reaction and neutralizes it, but not cause free atoms of chlorine.

2. 
   AlanWS | Jan 14, 2005 01:56am | #12

   Chlorine bleach is sodium hypochlorite, that is, the sodium salt of hypochlorous acid, which could be formed by treating the acid with sodium hydroxide. It is basic, not acidic. (Actually, there are other types of chlorine bleach, but that's laundry bleach.) Rinsing out the excess with water and/or baking soda is a good idea, but not because of acidity of the bleach. Over time, acids can be formed in wood or paper by oxidation, and it may be that washing with baking soda would leave traces to neutralize the forming acid. That may be the reason it was suggested. I don't know whether it's a good idea, only that it's not to neutralize the bleach itself.

1. 
   AlanWS | Jan 14, 2005 02:07am | #13

   Here's more info from Jeff Jewitt: http://antiquerestorers.com/Articles/jeff/using_wood_bleach.htmIt sounds as if peroxide bleach (the two part stuff) is more effecive for lightening wood. If you use swimming pool bleach (calcium hypochlorite), I would advise against using baking soda, since you can wind up making calcium carbonate (limestone) in the wood.

2. 
   UncleDunc | Jan 14, 2005 03:06am | #14

   >> It is basic, not acidic.Well I know it reacts with ammonia. Is that not an acid/base reaction?I thought at least one of the references I read yesterday said that when sodium hypochlorite is dissolved in water, part of it becomes hypochlorous acid again.

3. 
   AlanWS | Jan 14, 2005 06:37am | #15

   Hypochlorous acid is a rather weak acid, so a little of the salt would become the acid in water, but how much will depend on the acidity of the solution. Its primary reactivity is as an oxidizing agent, in common with hydrogen peroxide, but not with oxalic acid. (Oxalic acid I presume acts by solubilizing metal ions to remove mineral stains. This is a completely different mechanism from the other bleaches, so it should work on different stuff.) The dangerous reaction that takes place between ammonia and chlorine bleach is also an oxidation, forming chloramine and some other things, not an acid-base reaction. Usually, if you mix an acid and a base, the product salt is less dangerous than what you started with: sodium hydroxide and hydrochloric acid mix to form table salt. (Usually less dangerous, not always!) The reason it can be dangerous to mix a strong acid with a strong base is that a lot of energy can be released in the form of heat, causing the mixture to boil and spatter unmixed parts of the acid or base on you. But a weak acid, as is in vinegar, mixes safely with the hardener of epoxy to make a salt that is less toxic and easier to wash away.

2. 
   HowardAcheson | Jan 11, 2005 07:14pm | #2

   There are three bleaches used in woodworking. The one that removes the natural color of wood is a two part A/B bleach. You will find it at most big boxes and paint stores.

   Chloring bleach is used for removing dye stain and oxalic acid is used to remove water and metal stains.

   Howie.........
3. 
   mudman | Jan 12, 2005 09:32am | #4

   Thank yall,

   As always I apreciate the help. I know the the borg sells "wood bleach" I've read about its normal use, but now I forget. Will this lighten the colour?

   Mike

   please excuse my spelling.
1. 
   HowardAcheson | Jan 12, 2005 07:30pm | #8

   The "wood bleach" refers to the two part A/B bleach I mention above, as I recall.Howie.........

1. 
   mudman | Jan 14, 2005 08:48am | #16

   Thanks Howie,

   I looked at the stuff yesterday and it is a 2 part. I never realized it before. It said to nutralise with vinegar I believe. As always I was under the gun (one day late) so rather than take the chance on screwing up the finish I milled another piece. It was a 1" x5" fluted molding that I machined from 6/4 stock. I still had the router set up for the flutes so I made another one. Ill find a use for the other one later.

   Thanks for the help,

   Mike

    please excuse my spelling.

4. 
   budreaux | Jan 12, 2005 11:22pm | #9

   Doesn't green tinting in the stain counter the reddish hue as well?  This would be in addition to bleaching.

1. 
   forestgirl | Jan 13, 2005 07:05am | #10

   Great point, treefreak. Immediately makes me think of Jeff Jewitt.  Might be a good idea for Mike to go over to his site http://www.homesteadfinishing.com and ask Jeff for advice. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the  "I Rocked With ToolDoc Club" .... :>) 

2. 
   jackplane | Jan 13, 2005 05:48pm | #11

   yes, IME, tinting with green counters the red, so the color is neutral but not lighter.