Replies

1. 
   SgianDubh | May 15, 2009 08:45pm | #1

   Water, iron and the tannin found naturally in the oak combined to give the black staining. Assumimg the staining isn't deep it will, or should, plane, scrape and sand out at later stages of the production. Slainte.

   richardjonesfurniture.com

1. 
   tenderfootbob | May 15, 2009 10:38pm | #2

   Thanks Stainte. The reaction of tannin with iron was something that did not occur to me and explains why wetting down maple for planing for another project did not result in stains. Again, thank you so much.

   Tenderfoot Bob

1. 
   SgianDubh | May 15, 2009 10:48pm | #3

   I'm curious to know why you felt it necessary to wet quarter sawn oak with water prior to flattening it. I can think of no reason to do so if the wood is normal, and working conditions are also normal.

   Unless there is a compelling reason to wet the wood that I am not aware of I suggest you work the stuff dry for the rest of the job. Slainte.richardjonesfurniture.com

1. 
   tenderfootbob | May 16, 2009 01:32am | #4

   The quarter-sawn white oak stock I am using for the bed project I am making, is highly figured and thus much of the planing is necessarily against the grain. I have used, on the advice of "Knots", the light wetting of similiarly figured hard maple boards to soften the wood fibers to successfully avoid tear-out.

   Tenderfoot Bob

1. 
   SgianDubh | May 16, 2009 10:37am | #5

   Did you initially try planing the wood without wetting it first? And if you did, how bad was the the tear-out and did adding water help?

   Instead of using water you could try white spirits, aka mineral spirits in North America. One advantage of this is that you don't get the staining you experienced, although the smell is nothing to write home about!

   Additionally there are other factors that can exacerbate tear-out, such as:

   too heavy a cut

   dull knives

   feeding too fast 

   One technique you can use that will sometimes help reduce tear-out during both surface planing and thickness planing is skewing the cut. This seems counterintuitive because skewing effectively reduces the angle of attack of the knives which really should increase the likelihood of tear-out. It does however also mean the knives take more of a cross grain cut; and the technique loosely emulates the old trick of hand planing difficult figure, eg, ripple figure, across the grain to reduce tear-out.

   In any case if you have now successfully planed all your wood for this project the information in this post is probably of no help, except perhaps for a future project. Slainte.richardjonesfurniture.com

2. 
   HowardAcheson | May 16, 2009 05:35pm | #6

   And, as I said in the other forums you posted in, if you need to apply water to a wood high in tannin, only use distilled water. The minerals and metals in much water will react with the tannin and cause dark stains.Oxalic acid is the bleach that removes these stains.Like Richard, I too question the application of water to "soften" the wood surface. Water is sometimes used on highly figured wood like curly or birds eye maple but oak is not a wood that tends to need that type of treatment.Howie.........