Replies

1. 
   forestgirl | Aug 23, 2003 10:10pm | #1

   What are the other "small problems?"  Is it safe to assume, since you didn't detail them, that the white rings are your main concern?

   If you're going to clean first, use mineral spirits, not TSP.  If you mainly want to get rid of the white rings, try cleaning first, then apply alcohol to the rings, let sit for awhile and see if the rings diminish.  If they do, repeat the process, if the don't then probably on to Plan B, which for me would be to sand out the imperfections and re-oil.

   In any case, I wouldn't apply oil now -- just makes the rest of the fixing-up more difficult.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

1. 
   Kevin | Aug 23, 2003 10:54pm | #2

   I'll ditto FG here with the exception of using alcohol on the rings. If the Walnut's finish really is nothing more than oil, alcohol isn't likely to help since oil isn't alcohol soluable. Other than that, though... ditto everything FG said.

   Also, keep in mind that as long as the existing oil finish isn't degraded... wetsanding with an oil finish is always a viable and widely accepted option on the imperfections, including the white rings. If it doesn't work, the worst thing that you've done is added some oil that needs to dry overnight before you can sand it off. It's worth trying IMO.

   Regards,

   Kevin

1. 
   Gretchen | Aug 24, 2003 01:40am | #3

   FG is telling a good way to remove white rings--just barely moistening a rag with denatured alcohol and wisping it across the white rings--it will release the water trapped in the finish perhaps.  You can also rub it with mayonnaise and let it sit a while to see if this will work.   Since there ARE white rings I think there is an oil "finish" on the table--one with some varnish.  The "wisping" may remove the white marks (which are IN the finish, not the wood).  It is a good way to start.

   another way (after the alcohol) is to try a product like Howard's Restor-a-Finish and see if that makes the top "serviceable".  It well may do the trick.

   So, try these steps and see what happens.  Then come back.  Definitely get rid of the white rings BEFORE applying ANY other finish.Gretchen

1. 
   scooter1 | Aug 24, 2003 01:52am | #4

   Toothpaste works well on the rings, too.

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

2. 
   Kevin | Aug 24, 2003 04:32am | #5

   Wiping a white ring with an alcohol-moistened rag is definitely the standard procedure for dealing with water rings in a shellac finish. No doubt about that. But, the original poster here stated that his is an oil finish. Oil, not being alcohol soluable, won't be fazed by an alcohol rag. Shellac is alcohol soluable, which is why that procedure works fantastically on shellac finishes.

   Actually, the white ring that's visible isn't moisture that's been trapped. Rather it is the resins in the finish that have been knocked out of precipitation by the presence of moisture. The moisture itself is long gone shortly after the ring is caused, leaving one with nothing more than an unsightly white ring of resins out of precipitation. What the alcohol does on shellac is it redissolves the top layer of the shellac, allowing the resin to go back into proper balance in the finish. Ketones (MEK, Acetone, etc.) do the same thing for nitrocellulose and acrylic Lacquers. Those solvents work for those finishes precisely because those particular resins are readily dissolved by those specific solvents without incurring any damage to the resins.

   What's happening on a non-compatible resin, if wiping with an alchol-moistened rag removes the ring, is simply the friction of the rag itself rubbing away the small amount of resin that's out of the mix and causing the white ring. IOW, the same thing could be achieved with simply the rag, or the rag and any number of other substances that won't do a thing to dissolve the resin. That's a perfectly good solution to some water blush marks, even with shellac and lacquer. It all depends on where the water mark is at in the finish. If it's on the surface then any polishing action will remove it by simply wearing a minute layer of the finish away. For water marks that are deeper in the finish, the only solution... if any solution will work at all, is to use a solvent that will dissolve the finish without damaging it. That's why I mentioned in the earlier post that oil is not alcohol soluable.

   Frankly, I don't know of any solvent that will dissolve a cured oil finish without permanently damaging it. Wet sanding blemishes in a cured oil finish with a fresh oil finish of the same type is a perfectly acceptable and very widely used technique.

   Regards,

   Kevin

1. 
   Gretchen | Aug 24, 2003 05:10am | #6

   I understand about shellac.  I also understand about varnish. I think in this case the "wisping" of alcohol may release the water vapor from the surface, even if the finish is not shellac.  I always suggest something like mayonnaise first.  We were just trying to be the least invasive.

   Gretchen

2. 
   Kevin | Aug 24, 2003 05:51am | #7

   I always suggest something like mayonnaise first.  We were just trying to be the least invasive.

   Absolutely. That's the best approach. You'd make a great art conservator with that attitude. I'm serious. :-)

   BTW, I suspect what mayonaise is doing on the white rings is the vegetable oil in it is simply filling the uneven surface caused by the resin bits being out of precipitation. When they're like that on the surface, they function the same way that flatting agents do - they refract light on the surface to change the amount of light that's reflect back at any given point. They also change the manner in which you percieve the light that is reflected back. That's why the ring appears white even though there's not a stitch of white pigment there. You could wipe mayonaise over a dead flat finish and wipe the worst of it off and there would be a satin sheen left.

   Regards,

   Kevin

3. 
   riverr1 | Aug 24, 2003 06:15am | #8

   Tooth paste is used also. This one comes from Koval's antique restoration book.

   Also, the white rings can be caused by heat. Hot coffee cups being the usual culprit. How that translates into different treatments per finish material---I don't know! 8*)

   Don

4. 
   Kevin | Aug 25, 2003 06:24am | #13

   Also, the white rings can be caused by heat. Hot coffee cups being the usual culprit. How that translates into different treatments per finish material---I don't know! 8*)

   That's a great point to make here, Don. Unfortunately, white rings caused by heat aren't repairable in the same way that blush rings are repairable. The heat damages the finish. The only remedy is to rub it out somehow (the toothpaste would work as long as the ring is on the surface and not too deep) or else strip and refinish if rubbing it out doesn't work.

   Regards,

   Kevin

2. 
   forestgirl | Aug 24, 2003 09:16am | #9

   Hoppy, just for fun, here's another technique for attempting to remove the white rings.  Probably falls into the same category as toothpaste, but more traditional, LOL.  Taken from The Weekend Refinisher by Bruce Johnson.

   • Clean area with a rag dipped in turpentine, wipe dry
   • Sprinkle the damaged area with fine ashes or rottenstone
   • Dip a coarse cloth in mineral oil, then lightly rub area in direction of grain, checking frequently, adding more oil and abrasive as needed
   • Lightly rub out entire top for uniform sheen
   • Wipe dry

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

1. 
   Gretchen | Aug 24, 2003 02:38pm | #10

   The rottenstone is about the same as toothpaste--a very fine abrasive.  Another thing that works in this way is old fashioned Wright's silver cream or the equivalent.

   And petroleum jelly as a grease may work to release the water vapor.Gretchen

1. 
   riverr1 | Aug 24, 2003 08:04pm | #11

   Dittos Gretchen on Rottenstone to toothpaste. I imagine that is why Koval's, considered by many the authority in restoration, discusses toothpaste. You can find it more readily and in more homes then rottenstone.

   Don

3. 
   mikehop | Aug 25, 2003 05:00am | #12

   Mineral Spirits worked pretty well.  The slab has about thirty years of wear so there was some other small debris on the wood( food, drink...).  I tried wet sanding and used 600 grit garnet paper and 600 grit emery cloth, but managed to make small scratches in the wood which now are really bothering me, but are barely visible.  So what did I do wrong?  Is 600 grit too low?  I was hand sanding and perhaps I just knocked off a little of the patina.  I am hoping that liberal coats of oil will help a little to correct the underlying scratches  but I don't see how.  Do others sand with the grain?  On a burl how would that be done?  Thanks in advance.  Best , Mike

1. 
   Kevin | Aug 25, 2003 06:31am | #14

   Did you wetsand with mineral spirits or with an oil finish?

   I suspect that the scratches you're seeing aren't actually in the wood, but rather are in the existing finish which soaked into the wood when it was originally applied. According to Jeff Jewitt ( http://www.homesteadfinishing.com ), 320 grit yields a scratch pattern that isn't perceivable by the naked eye. 600 grit is a heck of a lot finer than 320. So, it must be the oil finish that you are seeing the scratches in.

   Regards,

   Kevin

1. 
   Gretchen | Aug 25, 2003 02:15pm | #15

   It is time to strip the top of this table and get a good finish on it.  Gretchen

2. 
   forestgirl | Aug 25, 2003 07:39pm | #16

   Hoppy, I've wet-sanded red oak with Danish oil and 220 grit paper and achieved an excellent surface and finish.  There really should be no need to go about 400 grit.  You should be using your oil finish and Wet-Dry silicon carbide paper for this process.  Were you sanding using the mineral spirits??  Oops!  Garnet paper?  I'm guessing here, but I suspect the grain size/shape is too variable in garnet paper for this purpose.

   You can experiment on this table, learn some things, and if it doesn't work, go ahead and strip/refinish it.  So, next step?  Start the wet sanding as described above, but no finer than 320 to even out the scratches from the garnet paper.

   Are you absolutely sure there's nothing but oil on this table?  If there's any varnish or shellac (varnish as in an pre-mixed "Tung Oil Finish" or something similar), then all this wet-sanding is probably an exercise in futility.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

   Edited 8/25/2003 12:42:53 PM ET by forestgirl

1. 
   Gretchen | Aug 25, 2003 08:15pm | #17

   If there's any varnish or shellac (varnish as in an pre-mixed "Tung Oil Finish" or something similar), then all this wet-sanding is probably an exercise in futility.

   I have considered from the beginning that there is a finish on this table--hence the "release" of the vapor from the finish.  I think water on a plain oil finish would have left black marks--wood damage, not finish damage.Gretchen

1. 
   riverr1 | Aug 25, 2003 10:47pm | #19

   Dittos

2. 
   forestgirl | Aug 26, 2003 08:14am | #20

   Gretchen, I know you've considered it -- just trying to find out if Hoppy's not only considered it, but investigated and figured it out one way or t'other.  Good point about the color of the rings, and you're probably right -- stripping is no doubt on the horizon.  forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

2. 
   Kevin | Aug 25, 2003 08:17pm | #18

   Ditto FG's excellent thoughts/suggestions here.

   One word of caution, though... the grit used to wetsand with can influence the final appearance. With just an oil this is nearly a moot issue. But, with any type of pigment in a stain or oil and you will have to be very careful to test with various grits to see which is going to leave a comparable look.

   Regards,

   Kevin