Violin Forum/Message Board Forum Index Violin Forum/Message Board
Provided by Violin Vision
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

black spots on plate after water stain ?????

 
Post new topic   Reply to topic    Violin Forum/Message Board Forum Index -> Violin Making and Restoration Forum
View previous topic :: View next topic  
Author Message
jethro
Member


Joined: 07 Apr 2007
Posts: 178

PostPosted: Tue Nov 20, 2007 4:23 am    Post subject: black spots on plate after water stain ????? Reply with quote

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
Back to top
View user's profile Send private message
Chet Bishop
Super Member


Joined: 23 Mar 2007
Posts: 678
Location: Forest Grove, Oregon

PostPosted: Tue Nov 20, 2007 12:24 pm    Post subject: Reply with quote

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
Back to top
View user's profile Send private message Visit poster's website
Andres Sender
Super Member


Joined: 23 Mar 2007
Posts: 275
Location: N. CA

PostPosted: Tue Nov 20, 2007 4:15 pm    Post subject: Reply with quote

...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.
Back to top
View user's profile Send private message
jethro
Member


Joined: 07 Apr 2007
Posts: 178

PostPosted: Wed Nov 21, 2007 1:48 am    Post subject: thats what I was afraid of ...... (!@?**$#@@&%!!!!!!!!!) Reply with quote

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 ----- ! Smile

Thanks , Tim
Back to top
View user's profile Send private message
jethro
Member


Joined: 07 Apr 2007
Posts: 178

PostPosted: Fri Nov 23, 2007 4:20 am    Post subject: titrate out the tannic acid ? (!) Reply with quote

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
Back to top
View user's profile Send private message
luthier9010
Junior Member


Joined: 02 Sep 2007
Posts: 3

PostPosted: Sat Nov 24, 2007 8:05 pm    Post subject: Reply with quote

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
Back to top
View user's profile Send private message
Mat Roop
Senior Member


Joined: 24 Mar 2007
Posts: 911
Location: Wyoming Ontario

PostPosted: Sun Nov 25, 2007 12:20 am    Post subject: Re: thats what I was afraid of ...... (!@?**$#@@&%!!!!!! Reply with quote

jethro wrote:
No more steel wool ever - maybe no more even in the building !
BAN STEEL WOOL ----- ! Smile


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
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    Violin Forum/Message Board Forum Index -> Violin Making and Restoration Forum All times are GMT - 4 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group