Replies

1. 
   saschafer | Jun 18, 2009 04:07am | #1

   The iron reacted with tannin in the wood to create the black color. I don't know if there's a practical way to remove it from walnut; it can be removed using oxalic acid bleach, but that will also bleach out the natural color of the wood.

   Common woods most susceptible to this are walnut, oak, cedar, and, to a lesser extent, cherry.

   -Steve

    

1. 
   SteveSchoene | Jun 19, 2009 06:59am | #6

   Oxalic acid is what you want to remove the iron discoloration.  It doesn't remove the natural color of the wood--it's not the same as the A - B wood bleaches (sodium hydroxide and hydrogen peroxide) that can turn walnut all the way to white.  The other bleach used in woodworking is chlorine bleach which removes most dyes and a few other stains and also has minimal effect on the natural color of the wood. 

2. 
   hammer1 | Jun 18, 2009 04:56am | #2

   Steel or iron pipe isn't the way to go. Your work piece has to be suspended above any condensed water that will accumulate in the steam box. You have deeply stained the walnut and there isn't a fix except to start over.

   Beat it to fit / Paint it to match

1. 
   Zigs | Jun 18, 2009 05:18am | #3

    

   Thanks guys. Luckily this was just an imromptu test on one molding piece to see if we could achieve the bend.  I plan on making a proper steam box with stainless steel rods as 'shelves' and some holes in the bottom to let cool air and condensed water escape.

   Hopefully that will solve the staining issue.

   Zigs

   Edited 6/17/2009 10:20 pm ET by Zigs

1. 
   DonfromUtah | Jun 18, 2009 05:22am | #4

   Depending on the alloy, stainless steel can rust under certain conditions.  If it can rust, it can discolor wood.  Dowels to support the molding may be the way to go.

3. 
   ASK | Jun 18, 2009 04:03pm | #5

   When I was bending a 5'+ piece of 1 X 4 maple a bunch of years ago I bought a 6' piece of aluminum gutter downspout, plugged the ends with a hole at one end to drain the water and hooked up the steam hose and had no trouble at all.

   ASK

4. 
   BrentD | Jun 19, 2009 02:42pm | #7

   There is another way to bend walnut without steam.   You can bend finished woods without harm to the finish by using oil - a high temperature vegetable oil, like peanut oil - and infrared heat lamps. 

   I use this to bend 150 yr old walnut gunstocks and it turns the wood to a very rubbery consistency quickly.  The finish is unharmed when the vegetable oil is wiped off. 

   Brent

    

1. 
   saschafer | Jun 19, 2009 04:28pm | #8

   You do have to be more careful about overheating and burning the wood when using oil, though. That's actually one of the main reasons for using steam: it limits the maximum temperature to a little below the boiling point of water.

   -Steve

    

1. 
   BrentD | Jun 19, 2009 04:34pm | #9

   I suppose that could true, though I am hard pressed to see that as a problem.  It has not been the case for me using easily regulated lamps.  I have never heard of anyone burning or even blistering the finish on an antique rifle.

   Brent

5. 
   WillGeorge | Jun 19, 2009 07:30pm | #10

   I think all is well.. I am not into making wood as some plane sheet of glass you look at and see through..

   Wood is wood and as it should be. Like a Man and Wife that love each other.. May not get along sometimes... But mostly do.. All that counts.. I'd say that perfect finish in wood is Artificial and will always be that..

1. 
   BrentD | Jun 19, 2009 10:14pm | #11

   ?????????????????????????

1. 
   Eef | Jun 19, 2009 10:21pm | #12

   brent,
   one does not merely COMPREHEND our beloved will, one needs to FEEL into his meanings. hang in there. be patient with yourself. soon you will come to treasure his lovely articulations and wise words. his posts always make the knots experience richer.
   eef

1. 
   BrentD | Jun 19, 2009 10:29pm | #13

   Oh...

   I think I need a beer.

1. 
   Eef | Jun 19, 2009 10:45pm | #14

   brent,
   i'm buying.
   eef