Thread: Shellac mixture cloudy

Ho y,

Yeah, can be a bit cloudy, run it through a filter to get rid of most of that. What was the ratio of meths to shellac flakes? The formula I use is 12 g of shellac per 100ml of alcohol per pound cut, so for my normal 2 lb cut I add 25 g of shellac flakes to 100 ml of alcohol. The more shellac (or the less alcohol) the cloudier it will get I reckon. I assume you're using the good industrial meths, >95% alcohol?
Cheers Swifty

Originally Posted by yoboseyo

I'm preparing my own shellac mixture with flakes and metho. I ground up the flakes and put it into a dry soda bottle and covered it with metho. I gave it a stir by prodding it with a stick every once in a while. Two days later, it's still cloudy. I thought it was meant to be clear, and the cloudiness is sediment that is supposed to settle to the bottom?

Restorers Choice recommends strongly to use denatured alcohol instead of metho when making shellac.

Originally Posted by yoboseyo

Two days later, it's still cloudy. I thought it was meant to be clear, and the cloudiness is sediment that is supposed to settle to the bottom?

Flake normally has an opaque look to it when mixed . Nothing really settles to the bottom . Left for a few weeks it can get a more clear top layer sitting above the rest in the top 15% layer . If its not dissolving completely it could be to old, and when its like that you will get suspended rubbery little parts in it that will settle down low . Filter it if it has that . If its just opaque without that then its good to use .

Originally Posted by Swifty

What was the ratio of meths to shellac flakes?

I assume you're using the good industrial meths, >95% alcohol?
Cheers Swifty

I really didn't measure. I read that you can just fill it till it covers. I ground the flakes up first, and ground flakes takes up less volume, reducing the amount of solvent required to cover it. So it may be quite thick right now, but I can just add more to thin it out.

I'm using diggers metho, which is 95%

Just an update, left for a week and it hasn't separated into a translucent layer

edit: trying to filter it through a coffee filter. it clogs up the filter immediately

Originally Posted by mpot

Restorers Choice recommends strongly to use denatured alcohol instead of metho when making shellac.

It really makes no difference.

Originally Posted by yoboseyo

Just an update, left for a week and it hasn't separated into a translucent layer

edit: trying to filter it through a coffee filter. it clogs up the filter immediately

What are you planning to use the shellac for?

cheers Swifty

Originally Posted by Swifty

What are you planning to use the shellac for?

cheers Swifty

Finishing a shelf made from stringybark

I used the cloudy mixture for the first coat today. Seemed ok. Might stick with it.

I see you have used Diggers 95% so problem will have been with the shellac.

Where did you get the shellac flakes?
How long have you had it?
Was it part of Granddads collection of old stuff?
Was it in a paper bag, plastic bag or container of some sort?
Was it labelled on the container?
Was it kept in a metallic container?

If it is old shellac and it appears to have worked alright it could be that it may never fully harden. IE: if you put books, ornaments, etc. on the shelf, when you take them off, weeks or months later, there may be an imprint of the book or ornament in the surface of the shellac.

Bit of general info of others who are interested

Denatured Alcohol is... Methylated Spirits is... Ethanol all containing a denaturant to make it unpalatable as drinking alcohol.

For shellac making you need to have either 95% or 100% if you get it yours from the cleaning section of supermarket and it doesn't have 95% or 100% printed somewhere on the label it could have as much as 42.5% water in it and will be completely useless for shellac.

For Methylated Spirits/Ethanol/Denatured Alcohol (whatever you want to call it) to be classed as that product they must overproof, ie must be able to be lit on fire or contain more than 57.5% alcohol, at that rate it's ok for cleaning windows and not much more.

Shellac flakes, pre-mixed or made yourself, will split into clear and cloudy with the cloudy brown to tan bit on the bottom. That bit is the waxy portion, the clear (dark honey to treacle colour) is the unwaxed portion. The split should be obvious within at the least, hours or at most within a day of mixing it.

To test if your denatured alcohol has water in it add a few drops of mineral turpentines to it and shake it.

• If it goes ever so slightly cloudy, it is probably 95% and fine for shellac.
• If it goes obviously cloudy it is less than 95% and not good for mixing shellac. This could account for the shellac not fully dissolving.

Hope this is of interest or help to some.

Cheers - Neil

A Polishers Handbook
For more on Shellac, and other finishes.

The Shellac is "Uni-pro" and it came in a plastic bucket. I've had it for ~2 years, but haven't opened it. It was sitting on a garage shelf not exposed to sunlight.

I've only put the first coat on. Should I just sand it back as I normally would, and then prepare a fresher shellac mixture for the finishing coats?

Hello yoboseyo

I would suggest you put some into a class jar as is (not crushed up) and add enough metho to fully cover it with about 10% extra.

Stir it with a non-metalic stirrer for a few seconds, every 10 -15 min If it isn't all dissolved within a couple of hours it may well be very old and not much good.

2 years in a garage shouldn't hurt it. However, if it came from a reseller that didn't sell much of it then it could be 2, 3 or even 4 times older than that. If it came directly from Uni-pro then it should be fine and mix down really quickly.

Cheers - Neil

PS PM sent to you.

PPS as for sanding I would leave it for the moment as it may clog your abrasive and just make a mess. stick your thumbnail into the surface and see if it will scrape some of the finish off. If not and it feels really hard you should be able to sand it without too much trouble. If not real hard try washing it off with metho. and clean dry cloth to clean up with.

Originally Posted by ubeaut

PPS as for sanding I would leave it for the moment as it may clog your abrasive and just make a mess. stick your thumbnail into the surface and see if it will scrape some of the finish off. If not and it feels really hard you should be able to sand it without too much trouble. If not real hard try washing it off with metho. and clean dry cloth to clean up with.

Thanks, I tried this, and it seems as if it's firmed up nicely as I was able to sand it without trouble. I didn't manage to sand much off, but removed the rough parts where I had lumped the shellac

I am going to finish the job with this batch, as there has been nothing wrong with it so far. I just need to work on my technique and spread it smooth.