I have some cherry table legs that I sanded to 220 grit and popped with Boiled Linseed Oil, (BLO).
I padded on 4 coats of 2 lb cut Garnet shellac. I tried rubbing out with 400 grit paper and mineral spirits. It took everything off, even the BLO. So I did the same with 2000 grit paper. It left some shellac but I can see that it isn’t level.
What am I doing wrong? Do I need more mineral spirits? (Like we used to sand cars, really wet.) Do I need more coats of shellac, say 6 or 8 total? Can I mix a 1 lb “wash coat” and level that way? What about rubbing with an alcohol pad to level the finish? Is the ultimate answer French Polish?, (Which I would only do as a last resort.)
The quilted maple table top was finished with BLO and blonde shellac and there were no problems with it. It looks GREAT!!! It’s an occasional tables so shellac is OK for the top.
Any help or advice would be appreciated. Thanks.
Replies
I guess your padding techniqe is at fault. Are you using oil, like mineral oil, in the traditional french polish technique?
If you are padding on Shellac without oil you have to move very fast allowing the pad to pass over an area only once. if you work an area you will disolve the previous coats and never build up a finish. Using oil as a lube gives a smooth gloss finish without needing sandpaper. If you are not using oil I would recomend you brush or spray on the Shellac. It is very hard to pad on enough to be able to level the surface. On the other hand if you are going to use traditional French polish technique you will not need to sand (if you are doing it right).
I do not use Mineral Spirits for wet sanding untill there is enough Shellac built up that the spirits dosent penetrate into the wood. If you are using BLO this is even more importaint. Also dont use garnet sand paper on a finish, the black oxide type for metal is better. And yes use a lot of mineral spirits. Keep the surface wet do not allow a slurry to build up.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
guy,
Any time you sand right through a finish, you are either using too much force, sanding too long, or trying to level a very thin finish layer. Several coats of 2# cut should give enough "body" to start the leveling process. But I don't know how much shellac you are actually putting down with your padding technique. Your "rubbing" technique is wrong. Don't start using lubricant at this point. Here's my schedule for applying and rubbing out sprayed or brushed shellac.
Put down 1 or 2 coats of 2# cut. Allow to dry completely (several hours at least, overnight if possible). Shellac should sand to a fine powder. If it doesen't, it's not dry. Start with 220 grit on a padded sanding block when sanding flat surfaces. Regular, curved surfaces can use a curved block. Irregular curved surfaces need careful sanding with either a curved block, or completely by hand with a sanding sheet that has had the back "broken" well. Sand very lightly, just removing the tops of the shellac "mountains," nubs, dust and other irregularities, leaving shiny, unsanded "valleys."
Don't try to completely level at this point. You can't, and you'll rub through to bare wood if you try. Apply several more coats, allowing to dry completely and sand again. Use light pressure (little more than the weight of your hand and the block). More of the "mountains" will level and the shiny valleys will be smaller.
Apply a few more coats. Sand again. With each application of shellac and sanding, the leveled areas will grow and the shiny valleys will shrink, until the entire surface assumes a completely uniform, flat, ground-glass, matte appearance. It may take 5, 6, 7 cycles, or more, depending on your technique.
At that point, final rubbing out can begin with 4-0 steel wool or 400, 600, 800, 1000 grit "wet-or-dry" paper, each using mineral spirits or soapy water as a lubricant. You can stop at whatever finish surface you like, up through using automotive rubbing compound (red), auto polishing compound (white), swirl removal for a crystal-clear, glass-like surface.
Rich
Rich:Thank you. Let me say it again, THANK YOU!I have had considerable difficulty in rubbing out my finishes (shellac and catalyzed lacquer). I have many of your previous posts filed away, but I had not understood the following, so I kept rubbing through the finish, because I'm trying to do it too soon. It has been very frustrating."Don't try to completely level at this point. You can't, and you'll rub through to bare wood if you try. Apply several more coats, allowing to dry completely and sand again. Use light pressure (little more than the weight of your hand and the block). More of the "mountains" will level and the shiny valleys will be smaller.Apply a few more coats. Sand again. With each application of shellac and sanding, the leveled areas will grow and the shiny valleys will shrink, until the entire surface assumes a completely uniform, flat, ground-glass, matte appearance. It may take 5, 6, 7 cycles, or more, depending on your technique."Regards,Hastings
Good luck! It takes a while to do it right, but it's not hard at all. The rubbing out process probably removes more material than it leaves on the wood, but the result is a beautiful, uniform, hard film that then polishes easily to whatever final abrasive grit you want.
Rich
You might want to consider putting on more coats before sanding. Use a sanding block on flat areas and use a light touch. I decided to practice first when I used shellac before starting on a customer's piece, recently. It was my first real use of shellac and I sanded through on a couple of spots, too but part of finishing is stopping when the thought of "just one more pass" hits. That thought went through my mind a few times before I got the hang of it.
I didn't use oil when I sanded or leveled, I used water to sand with wet/dry 600 grit first, then 2000 grit. After I wiped it off and wiped it again with a damp cloth, I let it dry and gave it a few coats of paste wax.
I believe the British call dampening a cloth with denatured alcohol and wrapping it with another clean piece "spiriting off" and you can only make one pass in each area, then move to a new one. I made full-width passes under flourescent lights, so I could see the effect of each pass. I let it dry and watched as the surface turned to something I had never seen before- it looked wet but was totally dry. What a great finish!
I think your problem is all in step number 1... 'I have some cherry table legs that I sanded to 220 grit and popped with Boiled Linseed Oil, (BLO).'
You may not have given the BLO enough time to properly and THOROUGHLY dry before you started applying your shellac. You may be better off if you apply 2 or 3 coats of shellac and then, when thoroughly dry, VERY LIGHTLY 'sand' it with a scotch-bright pad, more to remove any slight imperfections than to level it. Apply another coat or two of shellac, again let it dry thoroughly and finish with wax, applied with the scotch-bright for a high gloss finish or just the scotch-bright for a matte finish. SawdustSteve
Steve,
It's not necessary to let the BLO dry before applying shellac.
Most people who use that technique (I don't) apply shellac immediately after wiping off the BLO and use it as lubricant, BLO dryes well under shellac.
If I recall there was an article on a recent FWWM on that technique.C.
CHere's the article you mentioned. Tomhttp://www.taunton.com/finewoodworking/FWNPDF/011186052.pdf"Notice that at no time do my fingers leave my hand"
Thank you everyone for your great input and advice.
I put four more coats of shellac on, dry sanding VERY lightly between coats with 400 grit wet/dry paper. I let everythnig rest over night.
Then I LIGHTLY rubbed with 2000 grit w/d and paste wax thinned with mineral spirits. The result was a "smooth as glass" finish.
Some picts are included below. Thanks again to everyone.
If you ever need advice on taking highly figured, exotic wood and turning it into sawdust and firewood, I'm your man...
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