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What's wrong with my shellac?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=37264		 Page 1 of 2
Author:  WendyW [ Sun Jul 29, 2012 10:53 am ]
Post subject:  What's wrong with my shellac?
I mixed a new batch of dewaxed platina shellac that I got from a supplier recommended on this forum as being very knowledgeable and concious of shellac flake deterioration. Shellac flakes were purchased in December or January and came with a label that said "check dissolution after Dec 2012", so they should still be good. They were stored in a cabinet in my dining room and the room is kept between 70-80 degrees. I'm in the desert, so humidity is usually not an issue, also they were stored in a sealed plastic ziploc. I will say that yesterday did happen to be an unusual humid day here, but I mixed them in the house with the a/c running. I ground them in a dedicated cleaned coffee grinder and dissolved them in Everclear 190 proof and have been stirring every so often since yesterday afternoon. The jar was brand new and had never had anything else in it. Today the solution is still cloudy and thick almost mushy. Could the flakes have gone bad that fast? I still have some solution that I mixed from these same flakes in February, that I tested this morning and it is drying fine, so I will use it for now. I had no issues when I mixed them in Feb.
I hate to think that fresh shellac flakes can't be kept more than 6 months!
Wendy
Author:  CharlieT [ Sun Jul 29, 2012 11:06 am ]
Post subject:  Re: What's wrong with my shellac?
Wendy, can you elaborate on what you mean by "cloudy"? My guess is the ground flakes just congealed into a mass at the bottom of the jar and are resisting dissolving, but I'm not sure based on your description. If it were me I would keep stirring it and give it some time.
Author:  WendyW [ Sun Jul 29, 2012 11:32 am ]
Post subject:  Re: What's wrong with my shellac?
Hi Charlie, no it's not congealed at the bottom. It is evenly dispersed throughout the liquid, and semi dissolved so it's kind of thick, and when you look through it, it isn't totally translucent. If I tilt the jar, when it flows toward 1 side of the jar, it leaves little tiny globs evenly spread on the other side. But I have stirred often and they are definitley not congealed, but in suspension. I'm of course assuming that the bottle of Everclear was not the culprit. It was a closed, 1/2 full bottle, bought in February. Thanks, Wendy
Author:  B. Howard [ Sun Jul 29, 2012 11:52 am ]
Post subject:  Re: What's wrong with my shellac?
Usually shellac that has expired simply wont dry completely. Sounds more like water in it to me. Kept in a closed bottle, that shoudln't be a problem. So, do you have kids? Teenagers perhaps? Could they have taken some Everclear to party and simply added water so you wouldn't notice?
Author:  WendyW [ Sun Jul 29, 2012 12:59 pm ]
Post subject:  Re: What's wrong with my shellac?
Good thought Brian, but no kids. The only one who could have tampered with it would have been my dog. :lol:
Author:  CharlieT [ Sun Jul 29, 2012 1:02 pm ]
Post subject:  Re: What's wrong with my shellac?
callyrox wrote:
Good thought Brian, but no kids. The only one who could have tampered with it would have been my dog. :lol:


Has the dog been sleeping more than usual? :mrgreen:
Author:  TRein [ Sun Jul 29, 2012 1:07 pm ]
Post subject:  Re: What's wrong with my shellac?
B. Howard wrote:
Usually shellac that has expired simply wont dry completely.

I have found that old shellac, won't dissolve completely even after weeks in solution with alcohol. I have only witnessed this problem with blonde shellac. I have seedlac that is many years old and still dissolves completely and dries quickly.
Author:  Michael.N. [ Sun Jul 29, 2012 2:24 pm ]
Post subject:  Re: What's wrong with my shellac?
TRein wrote:
B. Howard wrote:
Usually shellac that has expired simply wont dry completely.

I have found that old shellac, won't dissolve completely even after weeks in solution with alcohol. I have only witnessed this problem with blonde shellac. I have seedlac that is many years old and still dissolves completely and dries quickly.


Yes. That's my experience too. However it seems that some folk can keep blonde shellac for years and still not have any trouble:

http://www.toolsforworkingwood.com/Merc ... BlogID=235
Author:  WendyW [ Sun Jul 29, 2012 2:24 pm ]
Post subject:  Re: What's wrong with my shellac?
Well it certainly is acting like old shellac, although it shouldn't be. I'm going to email the supplier and see what he says. I just got back from the store where I bought a new bottle of Everclear. $17.00 for 750ML!!!!!!!!! gaah Really makes me want to rethink not using denatured alcohol, but denatured alcohol was making me cough every time I smelled it. I'm going to try and see if a few flakes will dissolve in a little of the new Everclear overnight. Wendy
Author:  Eric Reid [ Sun Jul 29, 2012 2:28 pm ]
Post subject:  Re: What's wrong with my shellac?
Wendy, I'm surprised you're having this problem. It sounds like you've done everything right. Platina flakes do have a pretty short shelf life. I think even Super Blonde flakes last a little longer. Still,these should still be good. If you keep stirring occasionally over the next couple of days, and there are still gelatinous floaters, I wouldn't use that shellac on a guitar. Call Vijay, and describe what's happened. I've never had to return any product to him, but I would guess you could get a replacement.
Author:  WendyW [ Sun Jul 29, 2012 2:40 pm ]
Post subject:  Re: What's wrong with my shellac?
Eric, it is Vijay I got it from, and I just read the interesting article that Michael posted the link to. They actually refer to an article written by Vijay in the article at toolsforworkingwood. I am going to email Vijay and see what he says. I have to add that I dug through my receipts and I actually purchased the shellac from him in October, so earlier than I thought but still only 9 months ago. And his label says that the dissolution needs to be checked after Dec 2012 so it should still be good. Even if it ends up dissolving in the next few days I will probably be reluctant to use it on a guitar.
Author:  Eric Reid [ Sun Jul 29, 2012 3:10 pm ]
Post subject:  Re: What's wrong with my shellac?
If you can get the floaters to dissolve, you shouldn't have a problem. I don't grind the flakes before dissolving them, so that slows things down, but Super Blonde and especially Platina flakes always take 2-3 days to fully dissolve, and are gummy, rather than sticky while dissolving. The darker shellacs have a much longer shelf life, and dissolve much more readily. I've had old shellac (nothing would make it dissolve) from other suppliers, but I've always had good luck with Vijay's flakes.
Author:  WaddyThomson [ Sun Jul 29, 2012 3:29 pm ]
Post subject:  Re: What's wrong with my shellac?
That is 190 proof Everclear, isn't it? They make a 150 proof which is all you can buy now in NC, unless you make special arrangements and buy a whole case.
Author:  runamuck [ Sun Jul 29, 2012 3:54 pm ]
Post subject:  Re: What's wrong with my shellac?
I used 150 proof Everclear once and got the same result as you.
Author:  Billy T [ Sun Jul 29, 2012 6:05 pm ]
Post subject:  Re: What's wrong with my shellac?
callyrox wrote:
Even if it ends up dissolving in the next few days I will probably be reluctant to use it on a guitar.


I can understand that! Even still, you can always test it on a piece of scrap.
Author:  WendyW [ Sun Jul 29, 2012 7:14 pm ]
Post subject:  Re: What's wrong with my shellac?
Yep, 190 proof. Eric, are you saying that it takes longer for shellac flakes to dissolve when you grind them, or just that platina takes longer to dissolve? This same platina dissolved overnight when I mixed it in Feb.
Author:  alan stassforth [ Sun Jul 29, 2012 8:18 pm ]
Post subject:  Re: What's wrong with my shellac?
Sounds like water to me.
Shellac flakes last a long time.
Once mixed, they say six months.
I don't grind, but stir every once in a while,
and in less than 6 hours, done.
Never seen a cloudy thang going on,
but I'm still new to shellac flakes.
Try using D.A.
and see what happens.
Author:  Eric Reid [ Mon Jul 30, 2012 3:23 am ]
Post subject:  Re: What's wrong with my shellac?
callyrox wrote:
Yep, 190 proof. Eric, are you saying that it takes longer for shellac flakes to dissolve when you grind them, or just that platina takes longer to dissolve? This same platina dissolved overnight when I mixed it in Feb.


I'm sorry Wendy. No, grinding should speed the process. Platina is slow to dissolve. I don't bother to grind the flakes. Patience is my strength. Did you grind all the flakes when you received them? Maybe that would accelerate the aging.

I've looked at the blog that Michael linked to, and sent a response. I'm sceptical, but open-minded. At this point, I defer to Vijay's opinions (and my own experience).
Author:  TRein [ Mon Jul 30, 2012 6:52 am ]
Post subject:  Re: What's wrong with my shellac?
alan stassforth wrote:
Try using D.A. and see what happens.


This would conclusively prove if it is the alcohol or the shellac. Lowe's sells a "green" DA by the quart that is fairly benign and not mixed with lots of cheap diluent.
Author:  WendyW [ Mon Jul 30, 2012 9:23 am ]
Post subject:  Re: What's wrong with my shellac?
Eric, I only grind as much as I am mixing at the time.

I am going to do an experiment this morning. I'll put some flakes (unground) into 2 bottles. I'll add 190 proof Everclear to 1 bottle and Startex DA (a good quality brand) to the other. I'll agitate periodically throughout the day and post the results here.
Author:  Eric Reid [ Mon Jul 30, 2012 2:00 pm ]
Post subject:  Re: What's wrong with my shellac?
I received a prompt response to my email from Joel at Tools For Working Wood:

Eric,
Thanks for your email.
Age is not the issue, oxygen is.
Since my blog we have seen shellac that won't dissolve even if broken up.15 year old platina and some few year old super blond. The factor is storage and temperature
We took an oxygen barrier bag, filled it with brand new shellac,pumped it full of oxygen, sealed it and waited a few days. The stuff would not dissolve. Did the same with with oxygen absorbers - no problem. Now all our shellac is packed in oxygen barrier bags with a dessicent (probably not needed) and a oygen absorber. Heat is still an enemy but really because of clumping not because of polymerization. Although the heat might speed it up.

Storing dewaxed shellac on a shelf in a non-barrier back will greatly reduce it's shelf life. that being said oxygen works from the outside in so large flakes, broken up have a longer shelf life than small flakes with more surface area.

thanks,
joel
—
Tools for Working Wood
Author:  JoeUlman [ Mon Jul 30, 2012 2:03 pm ]
Post subject:  Re: What's wrong with my shellac?
In my experience, blonde/super blonde flakes can take from 1 to 3 days to dissolve in 190 proof ethanol. I don't grind the flakes, I just dump them in a shallow glass jar, pour in enough ethanol to make a 1 or 2 lb cut, screw on the lid tightly and let stand, with a brief swirling of the contents once a day to check if the flakes have completely dissolved.

Since alcohol readily absorbs moisture from the air, it's a good practice to keep the bottle of alcohol and mixing jars tightly sealed at all times; I use pipettes to draw out small portions of mixed shellac to use as needed and quickly reseal the jar.

I haven't yet had issues dissolving older flakes that have been stored in a cool dry place for over two years. I'm not sure why or how properly stored flakes would go bad but I'd certainly like to hear details about this from someone in the know.
Edit: I see Eric has just shed some light on this as I was posting. Thanks.

Joe
Author:  Bryan Bear [ Mon Jul 30, 2012 2:14 pm ]
Post subject:  Re: What's wrong with my shellac?
I don't want to hijack this thread, but I think this is related. . . I have some blone that has been sitting for a long time and no longer dissolves completely. I have been using it and discarding the shellac that hasn't dissolved. It seems to dry properly, I just have some that is still in the jar undissolved. Should I not be using the mixture?
Author:  Eric Reid [ Mon Jul 30, 2012 2:29 pm ]
Post subject:  Re: What's wrong with my shellac?
Bryan Bear wrote:
I don't want to hijack this thread, but I think this is related. . . I have some blone that has been sitting for a long time and no longer dissolves completely. I have been using it and discarding the shellac that hasn't dissolved. It seems to dry properly, I just have some that is still in the jar undissolved. Should I not be using the mixture?


Bryan, the first time I encountered shellac that wouldn't dissolve, I tried heating it in a double boiler. That didn't help. I filtered out the floaters, and used the shellac to French polish a guitar. The finish crazed badly. I don't know if it crazed because it was old, or because of the heat (although many finishers heat their spirit varnishes), or if there was another factor involved. I haven't felt the need to really sort it out. Now when shellac won't dissolve, I throw it out. I've never had another finish craze like that.
Author:  WendyW [ Mon Jul 30, 2012 2:35 pm ]
Post subject:  Re: What's wrong with my shellac?
Thanks for posting that reply from Joel, Eric. Interesting about the oxygen. So can someone explain what an oxygen barrier bag is?

Progress on the experiment... So far both jars appear to be dissolving better than the one I had the problem with, which leads me to think there was a problem with the older bottle of Everclear. I am not making any conclusions until they have completely dissolved. The only other factor that chenged is that I did not grind these. And I probably won't be grinding them anymore, now that I see they seem to dissolve at the same rate anyway.
Wendy
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