Replies

1. 
   Andrew | Jul 20, 2004 02:24am | #1

   If the plywood was in contact with rusted or even damp metal that could create a stain just like you mentioned. Turners sometimes use this techinique to color there bowls by using various types of metal swarf and water to create some very interesting and artistic stain patterns. sprinkle on metal swarf, mist with water and let it sit for a while. Iron and steel would give you red, copper would create green stains for example. I'm not sure what type of metal would stain the wood blue, but I've seen it before.

   Andrew

1. 
   hartproject | Jul 21, 2004 09:06pm | #2

   Good call, I have to admit I use an old knife with my wet rags to clean the glue out of the cracks wich would explain the dots on the maple. My knife has brass in it, maybe brass makes the blue.

2. 
   DaveHeinlein | Jul 21, 2004 10:35pm | #3

   On Oak, iron or steel will leave blue or black stains. This could possibly be true with Maple also.

2. 
   SRToolguy | Jul 22, 2004 07:14am | #4

   Dude, you're gonna think I'm absolutely nuts but what the heck, I'll risk it... LOL. So, whats your vitamin intake been like lately... Iron suplements, maybe a little copper sulfate ..... Sounds kinda weird but it happend to me. Seems I was overdosing a bit during a bought with the flu and my sweat was helping to relieve my body of the toxins. Along with that came the excess copper sulfate and iron that I had been taking in a multi-vitamin and it produced the same little blue spots with a tinge of red on some maple I was working on. It was driving me nuts and then suddenly went away. The only thing different was that I had cut back to normal dosage on the vitamins. I upped the dosage again just to see if it would re-occur and sure enough it did.

   I have no idea what even made me think it might be the vitamins but as far as I can tell it was.

   Sounds a little like a "Ripley's Believe it or Not" but its true. Does it matter that he's buried in the cemetary about 3 blocks from my house? LOL

   Sincerely;

   The Tool Guy

1. 
   UncleDunc | Jul 22, 2004 08:07am | #5

   Copper sulfate as a dietary supplement?!?!? Could you tell us what brand of multi-vitamins you were taking? Or do you take the copper in some other form and copper sulfate is how it comes out?

   Copper sulfate is seriously poisonous. Here's an MSDS.

   http://www.syndel.com/msds/copper_sulfate_msds.html

1. 
   SRToolguy | Jul 23, 2004 06:59am | #6

   Wow, maybe thats why I got over the flu so quickly ! Actually I was just joking around. I was under the impression that the post itself was a joke. Sincerely;

   The Tool Guy

3. 
   SgianDubh | Jul 23, 2004 10:11am | #7

   Aside from the joshing going on with alleged copper sulphate dietary supplements, maples and sycamores are prone to mould developing rapidly, and they stain the wood grey or blue. Basically, air borne spores of mould can develop in minutes if standing water is present.

   Typically during conversion of solid maple or sycamore logs they are immediately reared up on end off the saw and spaced with a stick top and bottom to allow passing air to dry out any surface moisture to help prevent the staining.  Later, the planks are stacked as normal to season, but if they are stacked too soon free water can get trapped resulting in sticker stain. This will result in the plank being rejected for show work.

   But back to green copperas, or ferrous sulphate. These chrystals are used to create harewood or grey wood out of maples and sycamore, and they are also used to change the colour of white oaks to anywhere between a light blue/grey to a strong RAF blue. Copper sulphate reacts (usually less visually satisfyingly) with the tannin in other tannin rich woods. I have no idea what it's reacting with in the maples and sycamores because neither are renowned for their high tannin content, but react it certainly does. Slainte.

   RJFurniture

1. 
   hartproject | Jul 27, 2004 11:38pm | #8

   Thank you for your input. Standing water has definately been present. So this makes sense.