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jethro Member
Joined: 07 Apr 2007 Posts: 178
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Posted: Tue Nov 20, 2007 4:23 am Post subject: black spots on plate after water stain ????? |
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I was staining my back plate with a yellow water stain and then a little later with a strong tea solution. after about 10 minuites I noticed nasty
looking black spots everywhere on the wood. very small spots- like
a liquid splatter which bled while wet.
could this be ------
1. tea leaf particles from the tea solution that got through the tea bags ?
or
2. possibly small bits of steel wool which lodged in the grain and made a
rust stain on application of water based solutions ? I had steel wooled
the surface earlier in the day.
Anyone have this problem ???? (he asked stupidly)
Tim |
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Chet Bishop Super Member
Joined: 23 Mar 2007 Posts: 678 Location: Forest Grove, Oregon
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Posted: Tue Nov 20, 2007 12:24 pm Post subject: |
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Yep-- those are steel wool flecks, reacting to the tannic acid in the tea...sorry. The tannic acid/ iron combination has been used for centuries to make black ink. I don't know of any way to get it out. Maybe someone else can come to the rescue. (BTW, this is the way people dye the black part of their purfling, frequently.)
Chet |
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Andres Sender Super Member
Joined: 23 Mar 2007 Posts: 275 Location: N. CA
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Posted: Tue Nov 20, 2007 4:15 pm Post subject: |
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...and it's why you don't use steel wool on wood. Some bleaches may help, I believe oxalic acid is the one for iron stains. |
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jethro Member
Joined: 07 Apr 2007 Posts: 178
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Posted: Wed Nov 21, 2007 1:48 am Post subject: thats what I was afraid of ...... (!@?**$#@@&%!!!!!!!!!) |
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I just happened to have some oxallic acid. I am sanding it out with 400
grit to some success. I have gotten about 95 % out by sanding so far,
but sanding -making the plate thinner- was the last thing I wanted to do.
The little spits have the appearance of splinters. There are more in the
center there the grain is perpindiculat to the surface. May try the acid
on the ones that won't come out.
Tonight I completely cleaned off my bench, blew it off with compresses air,
sanded the surface, blew again, then a wash down with solvent and clean
rag to rid any residue of steel wool !
Thank you SO MUCH for filling me in on the source of my spots.
No more steel wool ever - maybe no more even in the building !
BAN STEEL WOOL ----- !
Thanks , Tim |
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jethro Member
Joined: 07 Apr 2007 Posts: 178
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Posted: Fri Nov 23, 2007 4:20 am Post subject: titrate out the tannic acid ? (!) |
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Could I neutralise the acis with a mild base (amonia maybe?) or is it
the tannic acid that increases the flame contrast in the maple ?
Are there other substances which will also increas the flame contrast
and not turn steel wool flecks black ?????
( I know I as wishing for the moon ......
But the tea does work REALLY WELL !
How about decaffinated tea ????? Is it also contain tannic acid ?
Tim |
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luthier9010 Junior Member
Joined: 02 Sep 2007 Posts: 3
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Posted: Sat Nov 24, 2007 8:05 pm Post subject: |
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Don't feel like your the only one who's had this problem. It's a hard lesson to learn about steel wool. Mine happened with alum. I've quite using steel wool in between coats of varnish, because it just gets everywhere. It's not hard to get off the varnish but it gets everywhere else (clothes, bench, any thing that's magnatized, and eventually making it's way into the varnish pot).
Just a note 3M makes a new product ( I think it's new ) called Sand Blaster. Its soft rubber type stuff kind of cross hatched looking coated with grit. It works really well, it last a long time and is very flexable. I've been using the 400 grit. The flexability makes it easy to use on backs and tops around the edges. You can use it with water. They also make a foam rubber that is also coated with grit. I like the 320 grit. Both products can be used with water. I like these products much better than sandpaper, they're soft and much more flexable. I have been tring different finishing products. These products will make it easy to get rid of the steel wool in between coats of varnish.
Berl Mendenhall |
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Mat Roop Senior Member
Joined: 24 Mar 2007 Posts: 911 Location: Wyoming Ontario
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Posted: Sun Nov 25, 2007 12:20 am Post subject: Re: thats what I was afraid of ...... (!@?**$#@@&%!!!!!! |
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jethro wrote: | No more steel wool ever - maybe no more even in the building !
BAN STEEL WOOL ----- !
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No so fast!!... good quality oil free steel wool has its place...not on bare wood.... but it does work very well on well sealed finishes. Particularly, It works very well on bow restoration.
Good luck on beating your black measels! Mat |
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