Replies

1. 
   saschafer | Apr 23, 2009 03:49pm | #1

   Zinsser guarantees 3 years from the date on the can. For shellac you mix yourself, you shouldn't expect to get more than a year from the mixing date (Zinsser includes some additives that extend the life of their premixed shellac).

   You can do a simple test: Take a little shellac and put a drop on a hard surface, like a piece of glass. Let it sit for 24 hours. If you can still dent it with your fingernail after 24 hours, it's past its prime.

   The cloudiness of your orange shellac is probably wax. If you let the container stand for a while, the wax will gradually settle out to the bottom.

   -Steve

    

2. 
   SteveSchoene | Apr 23, 2009 04:24pm | #2

   No, the esterfication that causes the problem as shellac ages goes on regardless of whether the can has been opened.  It starts as soon as it has been mixed with the alcohol. 

   Zinsser guarantees 3 years, but since you can't know how it has been stored and handled and whether their definition of "OK to use" agrees with yours, I'd give it a bit of margin, and certainly test any shellac more than a year old before putting it on an actual project.  Shellac you mix from flakes has a shorter life as a liquid than the Zinsser liquid shellac because of certain processing they do to the shellac. 

   I agree that the cloudiness you saw was likely the wax.  On wood it doesn't seem to cause as much haziness as you might expect in the can. 

3. 
   Jimurock | Apr 23, 2009 07:50pm | #3

   I can't remember from your other thread whether you absolutely needed dewaxed shellac.  If by "clearcoat" you mean Bullseye Clearcoat, then that isn't dewaxed -- for that you need Sealcoat, which is harder to find in stores.

   Jim

1. 
   stewie | Apr 23, 2009 10:31pm | #4

   Hi Jim I am using a L.V. water based dye to color some beech for one project , and some maple and cherry for a 2nd . So the plan is a thin coat of shellac sealer over the dye, then Waterlox's Original oil based varnish and oil as a finish. The shellac is to stop the dye from bleeding thru , and from the oil in the varnish from making the cherry blotchy. I understand Zinsser's Bulls Eye Seal Coat is a 1 lb. cut of de-waxed shellac. Other posters have said there is not enough wax in regular/thinned shellac to worry about. Stewie
   The Sawdust Shop

1. 
   saschafer | Apr 23, 2009 10:44pm | #5

   SealCoat is a 2-lb. cut.

   Wax in your shellac is only of concern under polyurethane varnish or waterborne finishes.

   -Steve

    

2. 
   SteveSchoene | Apr 24, 2009 02:15am | #6

   Waterlox is  not a varnish and oil mix.  It is strictly a varnish.  That makes it a much better product over oil/varnish mixes if you put it over shellac.  Now if you apply it and wipe it off like an oil/varnish mix you will get a similar effect, albeit a bit more protective.  But, you don't have to do that, you can let it build a film, of pretty much however thick you want it.  (Though thin coats are still best.) 

   Waterlox will adhere over shellac with wax in it, while waterborne finishes and polyurethane varnishes may have problems. 

   Edited 4/23/2009 7:17 pm ET by SteveSchoene

1. 
   stewie | Apr 25, 2009 04:53pm | #7

   Thanks, Steve Just one more detail before we put this to rest. I plan to do a couple of coats of a 50/50 mix of oil (Boiled linseed or tung) and the Waterlox over a Shellac sealer. I think a little wax in the shellac should not be a problem with the oil?? Stewie
   The Sawdust Shop

1. 
   [email protected] | Apr 25, 2009 06:56pm | #8

   That schedule doesn't quite sound right. The oil is normally used as a penetrating finish. Applying it after the shellac sealer means it can't penetrate. I could easily be wrong, but I don't think it will work well. Be sure to try this on a test piece first.

2. 
   saschafer | Apr 25, 2009 07:58pm | #9

   Let's step back a second and try to understand what you're attempting to accomplish here. Shellac, oil, oil-varnish mixtures, and varnish are all good finishing materials. But I can't see using more than two on any given piece, and certain sequences (e.g., oil or oil-varnish mix after shellac) don't make a whole lot of sense.So, what are you trying to do? What is the effect that you want?-Steve

3. 
   SteveSchoene | Apr 26, 2009 12:38am | #10

   You can put an oil varnish over shellac only if the shellac is strictly a wash coat--one light coat of less than 1 lb. cut. In that case it will not have really sealed the wood, you get the necessary penetration of the oil/varnish and won't be wiping everything off, just everything on the surface. This will likely have a small beneficial effect on "blotching" of woods such as cherry or maple which are prone to that, and which your tests have shown the oil based finish to be too blotchy. Otherwise, oil or oil/varnish finishes are best used only on unsealed wood and should have all excess wiped vigorously off the surface. If left on the surface either finish will be soft and almost gummy.

4. 
   stewie | Apr 27, 2009 04:20pm | #11

   I have some cherry doors and face frame to go on a cupboard in the powder room that I want to match the look of the commercial (cherry)kitchen cabinets. I have some water based annaline dyes from L.V. to color match. Having read Mark Schofield's article "Blotch Free Cherry" in FW # 200 , the plan is ####wash coat of shellac (1 lb. cut , de-waxed) that I now have , sand to 320 , apply the annaline dye, then use Waterlox/oil mix , with a final coat of straight Waterlox. Result: Deep, lustrous sheen with lots of grain on display.
   If not a perfect match , at least it's in an adjacent room. Stewie
   The Sawdust Shop

5. 
   saschafer | Apr 27, 2009 05:00pm | #12

   If you're going to top coat with Waterlox, then I think you can omit the intermediate oil/Waterlox step. I doubt that it will make any difference in the appearance at all.

   But don't take my word for it--practice the finishing schedule on some scrap and see what you get.

   -Steve