Replies

1. 
   JeffKurtz | Nov 19, 2002 03:48am | #1

   Not positive, but I think a year is about all the longer shellac will keep.

   Jeff

1. 
   PlaneWood | Nov 19, 2002 04:08am | #2

   I thought flakes would last forever??

   PlaneWood by Mike_in_KatyPlaneWood

1. 
   JeffKurtz | Nov 19, 2002 04:26am | #4

   Just did a quick check over on Jeff Jewitt's site.  He doesn't give a time frame, but does say that it's important to use fresh flakes.

   Jeff

1. 
   PlaneWood | Nov 19, 2002 05:58am | #5

   Well durn!

   PlaneWood by Mike_in_KatyPlaneWood

1. 
   forestgirl | Nov 19, 2002 06:11am | #6

   Earlier today, I was researching some finishing problems and ran across some Dresdner info on the Zinsser Bulls Eye Seal Coat -- dewaxed shellac sealer that's sold in liquid form.  He loves it and says he probably won't be mixing shellac any more.  I've talked to a couple of WWers who have used it and really like it.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

2. 
   JeffKurtz | Nov 19, 2002 10:00pm | #15

   Forest Girl,

   I'm just getting a project ready for finishing and will be using Bulls Eye Shellac on it.  Will let you know how it turns out.  Not only does it dispense of the task of mixing, but it has a shelf life of three years.

   Jeff

3. 
   bobhallsr | Nov 19, 2002 07:34am | #7

   It hasn't been mentioned here, but alcohol will absorb water if it's been around a while and hasn't been sufficiently sealed. I have suspected damp alcohol when I've had trouble getting stuff like shellack into solution.

   BJGardening, cooking and woodworking in Southern Maryland

2. 
   Paul_Snyder | Nov 19, 2002 04:25am | #3

   Mike - flakes can go bad. Store them in a cool, dry place for longest life. The indicator they're bad is they won't dissolve. If you're mixing them in a warm room and they don't dissolve it's time to replace them.

   Paul

   F'burg, VA

3. 
   Marcello | Nov 19, 2002 05:55pm | #8

   PlaneWood,

   I hadn't realized the flakes go bad after a while either.  I recently made a batch and it took over two weeks to dissolve.  I thought it was taken longer than the last batch but could not be certain, (selective memory loss).  I hope the mix is ok, haven't used it yet. I better mix up what I have left and use it quikly.

   Have you tried mixing the rest of your flakes and let them sit untill dissolved?  If they are bad, you can't loose too much.

   Marcello

1. 
   bill_1010 | Nov 19, 2002 08:05pm | #9

   the others have hit it, either bad flakes or bad alcohol.

   You can get those vacum bag machines for food, but they work great for woodworking.  use it for storing shellac flakes, and even oil based finishes.  The vacum machines come with a canning attachment. Once i use a can i find a mason jar and label the contents and vacum seal up the remainder.  This keeps that nasty skin from forming.  Storing items like this helps prolong life if you dont plan on using it w/in a few weeks.  The bags are reuseble to an extent.

1. 
   davamoore | Nov 19, 2002 08:36pm | #10

   (Note:  Sorry, Bill, I forgot to click "All" in the "To:" box.)

   It seems to me that an important question is, Why do the flakes go bad?  Are the flakes themselves breaking down as a matter of time, or does exposure to light or moisture cause this problem?

   While I'm not sure, I lean toward moisture being the problem.  That said, wouldn't it help to add a couple of those little silica dessicant packets into the container I'm using to store my shellac flakes, or use the vacuum method described earlier?

   I'm ready to be enlightened... :-)

   David

   Look, I made a hat -- Where there never was a hat!

   Edited 11/19/2002 12:37:41 PM ET by davamoore

1. 
   BenM | Nov 19, 2002 08:45pm | #11

   I think moisture is a problem too.  I've read that hot weather doesn't do anything good for shellac flakes either.

1. 
   davamoore | Nov 19, 2002 09:16pm | #12

   One last comment/question (that may not apply to everyone) is, How often do you stir your flake/alcohol mix?

   I've found that if I let my shellac flakes sit for too long, undisturbed, in the jar of alcohol, I can't ever get rid of the clump that forms at the bottom.  I usually give the mix a good, 3-5 minute stirring as soon as I add the alcohol to the flakes.  Then, for the next couple of hours I give them a good stir or shake every half-hour or so, making sure I get all the undissolved flakes to budge (if any are stuck to the bottom).  Then, for maybe another 2-3 hours I give a stir/shake about once an hour.  One more time before bed, and by the next morning they're usually all dissolved, with no hard clump at the bottom.

   Again, this may be overkill and only effective with good flakes, but it seems to have solved my problem.  All told, the stir/shake time is about ten minutes total.  Plus, I love the odor of denatured alcohol... kidding!

   DavidLook, I made a hat -- Where there never was a hat!

2. 
   Paul_Snyder | Nov 19, 2002 09:40pm | #14

   There are a lot of good articles on shellac and alcohols on the web. Here's an excerpt from one of Jeff Jewitt's articles;

   "Dry shellac flakes store indefinitely under proper conditions, but contrary to what you may hear, it won't store forever. Given enough time, especially under hot, wet conditions, dry shellac reacts with itself to form polymers that are insoluble in alcohol. Shellacs that have been dewaxed are more prone to this. You can extend the usable life of dry shellac flakes by storing them after purchase in a cool, dry area -- a refrigerator is best. A test for suspected old shellac is easy -- simply dissolve the flakes in alcohol. Most shellacs should be totally dissolved within three days. If you see a gelatinous mass after this time, the shellac is past its usable life and should be discarded (don't confuse natural wax with this). If you just purchased it, return it to the company you bought it from. Sometimes in summer months, shellac will cake together. This is known in the industry as "blocking" and is not a sign of bad shellac. Break up the shellac with a hammer and dissolve it in alcohol as usual."

   Here's the link to the entire article - Jeff Jewitt on Shellac

   Paul

   F'burg, VA

3. 
   davamoore | Nov 20, 2002 04:58pm | #16

   Thanks Tom, and Paul for the reminder about Jeff Jewitt's article.  I actually read that article a while ago, but at the time I was searching for more information on the application of shellac, and I glossed right over the discussion about the effects of time on shellac flakes.

   DavidLook, I made a hat -- Where there never was a hat!

2. 
   b1gcountry | Nov 19, 2002 09:31pm | #13

   The reason shellac goes bad, if I remember what I read correctly, is estrification. The Shellac slowly breaks down over time. This happens very quickly in solution, but also happens, more slowly, in solid form. The process by which they manufacture blonde shellac also speeds up the process. The results don't affect the cured finish too much because it mostly affects the shellac's ability to go in and out of solution.

   This is mostly spewed out of something I read once, and can no longer remember where. I don't know very much about the process, but this is consistent with what I know about shellac, so it works for me. Maybe someone who knows more on the subject can chime in.

   Tom

4. 
   logcabin | Nov 20, 2002 07:36pm | #17

   Yup, I think BJ hit it on the head.  The alcohol should be dry.  It's much more likely your problem was water in the alcohol-should always use an unopened can.  I agree, mixing shellac is a pain the dust shute.  I recently bought some premixed blond from shellac.net and like it a lot.

   Tom from Clayton