Muddy shellac

[Trav]

Hi all

I was making up some shellac from flakes today. I used half a bag of the Ubeaut shellac mixed with 500ml industrial metho, as directed in the instructions. Even when I cut it to a 1/2 strength batch, it has gone really muddy, not the transparent amber colour I am used to. When applied it seems OK, but in the container it seems very odd.

Is this normal? I would traditionally make a 1/8, 1/4 and 1/2 strength mixes. I confess that I tend to use the white or hard shellac from the bottle, but I thought I'd try it with flakes this time. Perhaps I need to filter it or let the sediment settle.

Trav

[Christos]

After mixing and allowing it to settle over night I run the mixture through a coffee filter into another jar. Normally the heavier substances sink to the bottom of the jar. I try to pour as slowly as possible so that the clear liquid gets filtered first. Once the murky part hits the filter it gets to a very slow drip. I then use another coffee filter in another jar pour the rest of the jar into that, close the lid and leave over night.

Should end up with most of it clear.

[Xanthorrhoeas]

I haven't used those flakes but when I dissolve button shellac it has a lot of rubbish in it. I double filter it, first through ss mesh the through cheese cloth. However, natural shellac has a high wax content, which separates out as an opaque layer. I like the wax and make sure to mix it in when I polish as the final surface seems to benefit and take a wax final buffing well. But, I am usually polishing Australian antiques. However, it does provide a lovely transparent finish to new work as well.


Sent from my iPad using Tapatalk

[ubeaut]

Some of this is for the information of all shellac users or intending/future users.

Couple or few questions:


How long did you had the shellac before mixing with metho? Very old improperly stored shellac may not fully dissolve.
Was it still in the plastic bag or plastic container it came in? If stored in tin or out of the original container it can go off quite badly
Had it been stored in a hot shed or direct sunlight? Bright light can dramatically darken shellac.
Was it humid or damp when you did the mix? Dampness can make shellac bloom or look more muddy in a container.


When I mix up a big batch usually 25KG bag. I agitate it for a whole day or overnight then leave it sit fore a day (or overnight) and filter it through "voile" a very fine woven material sold as curtain material at places like Lincraft and Spotlight. Preferably man made fibre type rather than the cotton type.

Almost any synthetic material with a very fine weave will do. I have found that using muslin, cotton, etc will clog when filtering as the material swells and the weave closes up to some extent making for a very long filtering process. The voile will allow for a reasonably quick filtering but will trap all the rubbish, and there can be a lot of rubbish in most shellac flakes including bits of hessain or cotton from the bags it is stored and transported in, also dirt and grit from the washing of the shellac which is sometimes a bit ordinary along with undissolved bits of shellac.

Your shellac should dissolve almost completely in a couple of hours even with light, very occasional, agitation.

Ideally you filter and keep the whole of the shellac and don't just drain off the tops (the top section after the wax has settled out) unless you are using it for a special project that requires a slightly harder and shinier finish. Doing this can bite you in the bum if using it over ordinary shellac as it almost always craze down the track due to the lac of elasticity because the wax has been taken out of the mix.

The shellac flakes we sell are Machine Made SILTN or TN specifically for French Polishing and other wood coatings. When mixed it will be an opaque dark tan to brown colour. After it has settled the top half will be translucent to transparent brownish colour and the bottom half will look to be be a darker solid brown.

There is a pic below of a premixed bottle of French Polish (liquid Shellac). It is almost impossible to find a photo of a settled bottle of shellac. No one wants you to see that it settles out only how good it looks when it's mixed.

As a side note on our White and Hard Shellac's:

Both will layer and settle out the same way the orange shellac/French Polish does.
Big difference is you can see the settling in French Polish but it is not apparent in the white shellacs.
If the bottle isn't shaken before use or decanting you will not get the best of the shellac as the hardener and body of the shellac will be at the bottom of the bottle.
Even after decanting the shellac will still settle out so must be stirred prior to each use and sometimes during use.


Hope this long winded reply is of some help.

Cheers - Neil :U

http://macwood.com.au/images/fpol.jpg

[stainlesssteve]

awesome, thanks Neil

[Trav]

Thanks Neil. It was raining cats and dogs the day I mixed it, so that would probably explain it. Seems to work ok in the end. I did a few test coats on a scrap and it looked ok.

Thanks for your help

Trav