LumberJocks

Breaking up shellac flakes

  • Advertise with us

« back to Finishing forum

Forum topic by leftcoaster posted 12-01-2019 10:56 PM 561 views 1 time favorited 21 replies Add to Favorites Watch
View leftcoaster's profile

leftcoaster

284 posts in 1477 days


12-01-2019 10:56 PM

Shellac flakes sometimes form into pretty large lumps that take a long time to dissolve. Breaking them with a hammer sends them everywhere or, if contained in a plastic bag, tears the bag. I’m half tempted to get a cheap coffee grinder but don’t want to store it.

What tips do LJs have for breaking up large chunks of shellac?

Also – as I work a desk job all day, I can’t shake the bottle for most of the day. Is that why I end up with hard sediment at the bottom of the jar?


21 replies so far

View bilyo's profile

bilyo

959 posts in 1703 days


#1 posted 12-01-2019 11:38 PM

Get a small inexpensive coffee grinder similar to this. Even if your flakes are not in chunks, grinding them makes them dissolve faster. Sometimes you can find them cheap at flea markets.

View Snowbeast's profile

Snowbeast

121 posts in 1938 days


#2 posted 12-01-2019 11:58 PM

Or turn a mortar and pestle. Put your woodworking skills to work to benefit yourself.

View CaptainKlutz's profile (online now)

CaptainKlutz

2203 posts in 2095 days


#3 posted 12-02-2019 06:22 AM

Grinding flakes into dust only helps if you constantly shake or stir constantly. Otherwise get same results with flakes. Basically if you don’t shake the bottle, it takes much longer to dissolve, and usually ends up with clump in bottom – regardless of size of flakes. Even if you only shake the bottle once every couple minutes it helps reducing clumps, and dissolves faster. ‘Mix and forget’ process, can take a week to dissolve in cooler weather. Heat helps the process. Put alcohol filled bottle in hot water bath and stir for 15-30 minutes – done.
Better yet: Buy a surplus magnetic stirring hot plate for $20-$35 from fleabay or local lab auctions. Set it for 140°F, and let it do the stirring work. :-)
YMMV

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View SMP's profile

SMP

1556 posts in 506 days


#4 posted 12-02-2019 03:07 PM

How are you storing them? Maybe try double ziploc bags with those desiccant pouches to keep this from happening? I live in an area without much moisture and haven’t run into this.

View bilyo's profile

bilyo

959 posts in 1703 days


#5 posted 12-02-2019 03:13 PM



Grinding flakes into dust only helps if you constantly shake or stir constantly. Otherwise get same results with flakes. Basically if you don t shake the bottle, it takes much longer to dissolve, and usually ends up with clump in bottom – regardless of size of flakes. Even if you only shake the bottle once every couple minutes it helps reducing clumps, and dissolves faster. Mix and forget process, can take a week to dissolve in cooler weather. Heat helps the process. Put alcohol filled bottle in hot water bath and stir for 15-30 minutes – done.
Better yet: Buy a surplus magnetic stirring hot plate for $20-$35 from fleabay or local lab auctions. Set it for 140°F, and let it do the stirring work. :-)
YMMV

- CaptainKlutz


Great information. However, in my experience, after grinding and mixing, an initial thorough stirring and/or shaking is needed. After that, I may shake/stir one more time, filter it through a paint filter, and then use it. I usually find very little undissolved material in the filter. At most, only a few hours are required.

View Mr_Pink's profile

Mr_Pink

183 posts in 972 days


#6 posted 12-02-2019 04:49 PM

Mix your shellac in a Nutribullet or similar blender. Anything that can handle frozen strawberries can handle shellac flakes. Then clean the blender by making your favorite frozen alcoholic beverage.

Seriously, I mix shellac the day before I need it because I fall in between the shake-until-dissolved and mix-and-forget camps. I break up any large pieces by hand, mix with Everclear and give the mixture a good shake. I then shake every several minutes at first, but quickly start shaking with less frequency.

View leftcoaster's profile

leftcoaster

284 posts in 1477 days


#7 posted 12-02-2019 05:06 PM

Cool ideas, thanks all. I ordered a cheap coffee grinder and a magnetic stirring (Not heating) plate. I’m also getting some of the sprayers that pull directly from mason jars, which sounds awesome. Will report back.

View leftcoaster's profile

leftcoaster

284 posts in 1477 days


#8 posted 12-05-2019 02:38 PM

The magnetic plate arrived but not the coffee grinder so it seemed like a chance for an experiment with less than perfect conditions. I had some mostly small flakes and a few large chunks. This is garnet so it was hard to tell if the stirrer was able to do anything in the midst of that shellac. Probably not. The stirrer is not a heated model.

So I have a sous vide water bath circulator and I put the mason jar into that at 140 degrees for 30 minutes or less. That accelerated things nicely. The circulation of the water bath appears to create some movement in the jar but I can’t say how much. So I moved back to the stirrer and left that on for 6 hours. It’s nearly done and I shut it off. I expect it will be entirely done when I get home tonight.

This was a pretty heavy cut as I like to dilute it at time Of use. So that impacted stirrer performance I am sure.

A heated stirrer would likely be a simpler solution but as I have the circulator with its precise control I went with that.

View therealSteveN's profile

therealSteveN

4581 posts in 1174 days


#9 posted 12-05-2019 02:53 PM

Some people may recognize what this was before it took up life as a Shellac grinder.

My wife would kill me if I used her Coffee grinder.

-- Think safe, be safe

View ShopCat's profile

ShopCat

120 posts in 4179 days


#10 posted 12-05-2019 03:21 PM

I use a three step process:

I use a small old coffee grinder, obtained by buying wife a new one, and grind to a fine powder, weighing out the cut rate in a plastic bag on the small kitchen scale. I tend to go with a two pound cut, because I will be adding layers anyway.

Next, I pour the fine powder SLOWLY into the pre-measured denatured alcohol in a glass Mason jar with lid, at a rate that I don’t accumulate mush.

Last, I screw down the Mason jar lid and place the sealed mix in a very sunny location where it will take on solar heat. Being in the tightly sealed strong glass jar means it can get warm, be shaken, turned upside down, etc.

Result is well mixed hot shellac in about 30 minutes. Hot is good because I generally wipe on, usually attempting some form of French Polish, and the thinner mix penetrates deeply and dries instantly.

Of old, Shellac flakes could be hard to come by, but now days Amazon will have it to you in two days. I used to store it in ziplocks in the freezer to avoid getting lumps, now I just get it Prime when I see the need coming.

Don’t make it more complex than that, Shellac is a very simple finish. Do this once and you will never go back to the canned stuff. Some where out in webistan is a post by Bob Flexner of American Woodworker on French Polishing that cuts thru all the nonsense on how it all works. FP is also a very simple technique if you resist letting it get complex.

-- ShopCat

View leftcoaster's profile

leftcoaster

284 posts in 1477 days


#11 posted 12-17-2019 02:53 PM

Update: I did a variant of the transaction prescribed by ShopCat—made off with a coffee grinder from the house and didn’t even have to replace it!

Ground the shellac to a fine powder.

Set the magnetic stirrer going and slowly add powder, adjusting to keep the vortex moving. I ordered some of the larger stir sticks that I hope will make this less finicky.

Let it go while having lunch or a walk with the Mrs. and it’s ready to go.

View leftcoaster's profile

leftcoaster

284 posts in 1477 days


#12 posted 12-17-2019 02:55 PM



I use a three step process:

I use a small old coffee grinder, obtained by buying wife a new one, and grind to a fine powder, weighing out the cut rate in a plastic bag on the small kitchen scale. I tend to go with a two pound cut, because I will be adding layers anyway.

So that’s 4 oz to a quart of alcohol. do you then use a larger jar to mix? Or do you dissolve it as a thicker cut and then dilute to fill the quart jar?

View bilyo's profile

bilyo

959 posts in 1703 days


#13 posted 12-17-2019 03:41 PM


So that s 4 oz to a quart of alcohol. do you then use a larger jar to mix? Or do you dissolve it as a thicker cut and then dilute to fill the quart jar?

- leftcoaster


t doesn’t matter. What ever meats your needs.

View therealSteveN's profile

therealSteveN

4581 posts in 1174 days


#14 posted 12-17-2019 04:52 PM

Just keep in mind that once you mix it, there isn’t a way to make it a heavier cut, at least not of that mix. You can always dilute a little bit of it though if you need a lighter cut placed into a smaller container.

I have never seen use for anything over a 2# cut personally, so I start there. I find epoxy as a filler of voids is easier, quicker, and works better. Small voids I burn in with a knife, but I do use Shellac sticks for that, much easier to handle.

Other 2 things are, Shellac in a sealed pouch will be good for 3 years. Once mixed it has a life span of 1 1/2 years. The moral of that story is wait until you need it to mix it. Count on 2 to 3 days for it to make, and you will always have plenty on hand. I understand some voices are saying 30 minutes. I’ll not work on a project for a few weeks, and splash Shellac on it that I just mixed. I always wait a few days. Doing it quicker I have not had the great results I do waiting a few days.

Probably a lot of variant here. Some folks want to go authentic and use Indian product. I have always found everything I have gotten from Indian/Thai merchants to be dirty (think impurities). I like the German “machine made Shellac” much better, cleaner, easier to use from the start point.

A bit of info about Shellac, where it comes from, how it’s made, yada, yada, yada….

https://www.naturalhandyman.com/iip/infpai/shellac.html

-- Think safe, be safe

View leftcoaster's profile

leftcoaster

284 posts in 1477 days


#15 posted 12-17-2019 05:06 PM



Just keep in mind that once you mix it, there isn t a way to make it a heavier cut, at least not of that mix. You can always dilute a little bit of it though if you need a lighter cut placed into a smaller container.

Can’t you just mix in more shellac flakes?

showing 1 through 15 of 21 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com