Sanding Sealer Issue and Salad Bowl Issue

[Jeff Walters]

Hi Everyone,
I have been turning a bunch of bowls lately. Mostly Walnut, Maple and Cherry and Sycamore. I mixed up a sanding sealer of 50% non-waxed Shellac sanding sealer and 50% Alcohol. It goes on nicely however when I sanded again (From 320) I found that the end grain was still soaking up the finish. So my questions are, how many coats of sanding sealer should I need to apply and should I sand in between each coat?

Also, I have tried Salad Bowl Finish for the first time. I have my first coat on and wiped it on with a clean cloth rag as per the instructions however it is still tacky after 48 hours. At the 24 hour make I put a small fan on the bowl to help move air around and while that helped a little bit, there is still tackiness. Based on what I have read, this does not seem normal. Anyone have any suggestions? Note: Shop is in basement with an average temperature of 70 degrees)

Thanks,
Jeff Walters

[Doug Hepler]

JEFF,

Regarding the end grain soaking up finish, it will do that until the vessels become clogged with finish and gradually fill up. The diameter and depth of the vessels varies with wood species. Shellac does not cure. Each coat dissolves the previous one. I can imagine that this would really slow the process of filling those pores. Furthermore, you have diluted the shellac, which reduced the concentration of solids. It may be a long time until you get the result you want. I recommend that you try French Polishing with shellac. You might try a grain filler, dyed to match wood color. Or, switch to a high solids finish like varnish. You may get a smooth result in 4-5 coats (maybe fewer). Some people would use a cyanoacrylate finish but I have no experience with that except to know that it is extremely unpleasant to use.

Regarding salad bowl finish, you need to specify the brand. Some products with this label are just polyurethane varnish, some are drying oil (tung oil) and some are non-drying oil (mineral oil). The varnish should have dried by now. Mineral oil will never dry. By the way, any varnish is "food safe" after it cures.

Doug

[Jeff Walters]

Hi Doug,
The salad bowl finish I used is made by General Finishes.

Also, would a lacquer bash sanding sealer would work better?

Thanks,
Jeff

[Len Mullin]

Jeff, next time try not diluting the shellac so thin, try an 80/20 mix rather than a 50/50. Diluting it 50/50 makes the shellac to thin, and you have to reapply it so many more times to get the coverage your expecting and want.
Len

[Jeff Walters]

Hi Len,
Thanks for the advise. The reason I did 50/50 is that it was what I saw others online do. So I figured they were right since they were getting beautiful results.
Jeff

[Doug Hepler]

Jeff,

I doubt that a lacquer based sanding sealer would help to fill the end grain faster. French polishing of turned items on a lathe is a way to apply a thicker coating of shellac and get a brilliant glossy finish. It is worth learning how to do.

General finishes salad bowl finish is a wipe-on polyurethane "Oil modified urethane resin" varnish. Wipe on varnishes are just diluted brush-on varnishes. It should dry to a hard film in a few hours, overnight at the longest. One trick I have used successfully, to encourage drying, is to put the object into the sunlight. Just make sure that it does not get too hot.

Doug

[robert baccus]

Shellac's are full of problems--slow drying--slow buildup--ruined by an acahol drink in the future and easy to spot. A good laq. sanding sealer is a lifesaver here. Buy a good Heavybodied (such as Mowhawk) and use the first coat straight. Sand with 220 until some wood shows and follow with a light coat(sandthroughs will show). All pores should be filled and require more. Follow with several coats of spray lacquer and perhaps liquid compounds and waxes. laq. based S.S. dries quickly--all of this can be done in 4 hours. PS--wipe on poly,s (all poly,s) are almost impossible to patch or refinish without complete sanding to bare wood. It will not stick to it's self or anything else after a few hours drying. Bad scene.

[Pat Scott]

Jeff if you are trying to finish a bowl that will be used with food and then washed afterwards - a utility salad bowl - then I would stay away from poly or varnish or lacquer straight from the can, French Polish, grain fillers, CA, shellac, or any heavy bodied anything straight from the can. These are all film forming finishes and have no place on a utility bowl. I only make utility bowls, so here is my opinion:

For a utility bowl, I wouldn't bother with a sanding sealer. You didn't say what cut your non-waxed Shellac was to start with. IF you must use a shellac sanding sealer, then I would only use a 1 or 1-1/2 cut at most. Lacquer sanding sealer is OK if you want to use it (I make my own by diluting lacquer 50/50 with lacquer thinner - but I don't use it on bowls). IF you must use sanding sealer, I'd put on one coat of sanding sealer as described above, no need to sand afterwards because it's such a thin coat, and then some kind of oil finish on top. I used to use GF Salad Bowl Finish quite a bit, and the only time it wouldn't dry overnight is when I tried to use an old can. It will eventually cure, so just set the bowl aside and check it in a week or two. You don't have to put it in the sun, for me that just made it gummier. Throw that can out and get a new one for the next bowl. Salad Bowl Finish is not a wiping varnish, it is a Danish Oil. The difference between the two is that wiping varnish is full strength varnish that has been diluted 50/50 with mineral spirits. If you take that wiping varnish and then add Tung Oil or Linseed oil to it, now you have a Danish Oil. As Doug stated, GF Salad Bowl finish is an oil modified urethane resin. So GF is using urethane instead of varnish or poly. In my experience, Salad Bowl Finish has a lot of solids in it, and it doesn't take many coats before you start to build up a film finish on the surface. I have diluted Salad Bowl Finish even more with mineral spirits and it helped some. I would not use it full strength.

I'd have to look back through my notes from a Finishing Class that I took one semester and check the statement that shellac doesn't cure. I want to say that one coat might dissolve the previous coat, but I think that's only during a certain window. As far as alcohol from a drink dissolving the finish, studies were done that the alcohol in a normal drink is not strong enough to affect the finish once Shellac is cured. It would have to sit on the surface for weeks before it had any effect. Don't use French Polishing on a Utility bowl as that just builds up a film on the surface.

If you want to use Salad Bowl Finish straight from the can (GF or Behlens), I would only put on 2 or maybe 3 coats at most with no sanding sealer. As soon as you see a shiny surface start to show on the surface, stop. Yes end grain will soak up a lot of finish, and the first coat on bare wood soaks in like a sponge. But it's soaking in and starting to fill the pores. For a utility bowl you want the finish IN the wood, not ON the wood.

[Jeff Walters]

There has been so much good information for me to soak in. Thank you all for sharing your knowledge. I am turning a cherry bowl this weekend so we'll see how I do with the end grain. I'll report back and post a image of the outcome.

Thanks,
Jeff

[Brian Kent]

I nearly always use de-waxed shellac and have never thinned it. It has already been thinned down to the best mix. If others have further diluted theirs, then great, but it is just right for most uses out of the can.

The place I need the best-sealed end-grain is in the bottom of the cup portion of chalices. I turn on the lathe at about 250 rpm, with a cover on the lathe and surrounding area, and squirt the de-waxed shellac directly at the bottom of the cup. I make sure that the whole inner surface is covered and wipe off the excess bead of wet shellac at the rim. I usually do this 2 or 3 times. It is well sealed with almost all woods.

One of my reasons for using poly as the final coat(s) is that shellac is alcohol based and I have never actually tested to see if fully cured shellac would soften if you left wine in it for hours.