Hello All ! I need some help, I recently finished a table, which I done in mahogany. To bring out the color in the mahogany I used a finish the Peter Gedrys used in one of the FWW magazines. 3 parts polyurethane 1 part BLO 1 part naphtha. I but on three coats, and it turned out just great.
Now my question, in Lee Valley’s 2008/2009 catalog page 222 they have some pumice stone (fine abrasive powder) along with rottenstone and 3M rubbing pads. I would like to use the above to rube out the fine bumps on the table. I recall seeing a few years back where a small sack was made and rubbed on the top of the table, is this the same think I am trying to do.
My final question, will this give the table a very hard shine.
Thanks Jack
Replies
I don't think the pumice will remove the bumps; you'll need sand paper backed by a block to do that. Pumice is used to change/unify the sheen.
Rob Millard
http://www.americanfederalperiod.com
Rob is right on this--the powdered abrasives--pumice and rottenstone, or rubbing compounds don't flatten. Also remember that with your oil varnish mix, you should have very little if any film on the surface, and shouldn't have "bumps" on the surface to rub out. Even with 3-1 varnish/oil I would wipe the surface virtually dry after each application, not letting it build a film that would attract dust. You would have very, very little film thickness, so the sanding to remove dust must be VERY gentle--I'd use nothing coarser than 600 grit, and use a light touch. Even so you may need a final coat almost entirely rubbed off so it can't collect dust before it cures to get a final even sheen.
If you didn't fill the grain, you are going to have a big mess using any type of rubbing compound, pumice or others. Pumice is a very fine abrasive, like toothpaste. It will get in every pore. You have to use fine sandpaper to remove imperfections like dust nibs. Follow that up with 0000 steel wool. If you want more of a polish, then use a 3M synthetic pad. White is the finest.
Beat it to fit / Paint it to match
If by "fine bumps" you mean dust nibs, I think pumice, or rottenstone would be a good choice. The advantage of using these sorts of abrasive is that they don't try to flatten. They work the surface you have. Using a block on an uneven surface can result in high spots being over worked. Unless you have the experience and skill of Rob Millard or Steve Schoene you may find you can dig the corners in when using a block. Some guys use foam on their blocks for this reason.
I've used pumice and rottenstone with a paper towel and a dollop of BLO. If the pores aren't filled, it will fill them. My feeling is that it is old technology that may or may not be worth your while. Commercial automotive rubbing compound may well work as well or better. I've know commercial furniture makers who used bits of cardboard box. Like to hear Gedrys' view of this. The good thing about Peter is that he's done it all, seen it all, and has an open mind about these sorts of things.
Sparky, why don't you send him an email and ask him what he thinks? Send him a link to this thread as I'd like to know what he thinks. I really struggle with finishing and have struggled with this step in particular. I've tried at least some period finishes. I've had some success with loose abrasives. They are cheap, so it may be worth a try.
Adam
Sand paper does a much better job at removing dust nibs. You don't want to work the surface you have, you do want to work just the tips of the dust nibs to shear them off with as little disturbance to the surface in between as possible until you are adjusting the final sheen. It is true that if you have hand planed surfaces you would be better off without the block, just with folded paper, but I don't think it would take a lot of skill to avoid problems with a padded block on surfaces that have been leveled--ie. modern surfaces.
A very effective method for dust nibs, which does call for skills that I don't command, is a very light touch with a card scraper. The analogy I have heard is shaving a peach, as far as delicacy. That is a possible task, just not by me.
Jack,
Adam and Steve brought up an important point; using a block on a planed surface isn't a good idea. When I say planed, I mean the surface left by smooth plane with a nearly imperceptible camber. I have ever sanded a scrub/jack planed surface, and film forming finishes wouldn't' be appropriate for those anyway.
I should have noted that I use an eraser to back my sand paper. It may seem too small to be efficient, but it works quite well, and is cushioned enough not to dig in, but firm enough to level the surface.
Rob Millard
http://www.americanfederalperiod.com
Whoa, whoa, whoa! Come again Rob? Are we talking pink pearl or the school teacher's chalk eraser? Never seen that one in a tips and tricks column.Adam
Adam,
Well, until now it has been a closely guarded secret. I'm talking about the Pink Pearl. I actually have a supply of erasers that came in Happy Meals in the mid 1980's (Ronald McDonald, Hamburgular etc). They measure about 1 1/8" wide by 1 1/4" long. This came from my model airplane days (also in the mid 80's), when I used the eraser to back the sandpaper when sanding the seams true. I know it doesn't sound very efficient, but I've used them on everything from pipe boxes to sideboards. I have used the felt chalkboard erasers too, but not since I got a couple of felt blocks.
Rob Millardhttp://www.americanfederalperiod.com
I have hunks of felt from old snowmobile boots and a felt blackboard eraser, too. My favorite is a small block of wood with an 1/8" thick piece of leather glued on. I cut the finger tips off some leather gloves and wear them when the card scraper is to hot to handle. Someday, I may make a leather sleeve to fit over the scraper. I'll be ticked off if I start seeing these in the woodworking catalogs, just like manufactured router tables, plastic assembly blocks, push sticks and other things I never thought anyone would pay for.Beat it to fit / Paint it to match
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