How long should Shellac flakes take to dissolve?

[FenceFurniture]

I bought some shellac flakes just recently and in the absence of having Industrial Meths I decided to mix up just 100mls using normal meths to get the hang of it (I.Meths not available up here, so next time I go down the hill).

I used 10 grams of shellac flakes in the 100mls of meths, which is not full strength, but I'm glad I did. 24 hours later it's only about 50% dissolved, after frequent vigorous swirling. During the day I've had it sitting on top of the heater just to elevate the temp slightly (probably around 28°) as it was a cool day.

Is this a normal duration (what looks to be several days worth of sitting yet) or has something perhaps gone amiss?

[Pac man]

When u say normal meths is there an alcohol content marked on the bottle? Marked alcohol content of 95% on "shop bought " meths = good. No marking of alcohol= bad as this can have up to 40 % water as advised by the benevolent dictator in section 1's thread

[FenceFurniture]

It's Diggers brand 95% ethanol.

[Fuzzie]

I don't think shellac flakes have an indefinite shelf life. I had some that were >10 years old that just turned to a stodgy mass in Diggers Meths. Went and bought some fresher ones from the Green shed and they dissolved pretty quickly in the same meths.

[NCArcher]

I bought a cheap electric coffee grinder (About $10) and put the shellac through that. Dissolves in no time now but it was taking ages. Also only using 95% from Bunnies.

[Christos]

It should devolve fairly quickly.

I put the mix in a jar and close the lid. Then I shake vigorously for about 10 minutes. I will leave it for a little while and again shake the mixture. I will then leave it overnight and take a look. There should be crud on the bottom half of the jar with a clear almost transparent liquid on the top half.
Then filter the contents into another jar with a coffee filter. Trying to avoid the crud from filtering first. Leave the majority of the crud in the original jar.

[FenceFurniture]

48 hours later and it's getting there, slowly, and with some help. Yesterday I introduced a small block of wood to the mix to help break things up during agitation. I also stood the jars in near boiling water which will probably elevate the temperature to about 60° and then decline. I read on Sawmill Creek how one guy uses a nut (metal threaded type) to break it up, but I didn't want to introduce metal to it, as Ubeaut's site says don't store Shellac in metal (although it may not have any bearing for just a few days).

Later on I'll grind some up with NCA's suggestion of a coffee grinder and see how that goes. You'd have to think that would accelerate things dramatically.

[FenceFurniture]

Apparently the last thing I ground up in the coffee grinder was some spices. After a good clean out the small is still there so it may add a little piquancy to the Shellac aroma .

Also got a fresh bottle of Meths (still 95% though), and made up another batch of 10g/100ml with the powder/granules. It's only been about 45 minutes so far (in a warm bath) but it does appear to be dissolving faster. Overnight standing will tell me what difference there is. Have given it Christos' method of a 10 minutes shake too.

I can see that the granules have swollen up because when I first mixed it the level of sediment was much lower than it is now.



By the way, why is Meths called Meths, when surely it should be called Eths?
Ethanol is CH3CH2OH
aka C2H5OH (the latter is just an abbreviation)
and Methanol is CH3OH.

If I recall my 40 year old organic chemistry correctly the Meth means one carbon, Eth means two, Propanol has three, Butanol has four and so on (and verified from Wiki). Then there's Propranolol also known as Laughing Spirit

According to Wikipedia the denaturant that is added to Ethanol is Methanol (to make it taste lousy), hence it's been "Methylated".

In my travels on Wiki I saw another one called Nonane ("non" being nine carbons). So, if Franklins ever start selling it we could have Noname Nonane.

[Christos]

..............In my travels on Wiki I saw another one called Nonane ("non" being nine carbons). So, if Franklins ever start selling it we could have Noname Nonane.

I have seen the size of your shed and I think next time you should mix this outside.

[JDarvall]

I don't know if this is any help to you…. but this is what I do. some bloke may have something better.

I don't throw out any of the transparent mayo bottles from the kitchen when their empty. Wash them out and use them for shellac. There the ones with the twist nozzle. . Their perfect for shellac. There better than the tomato sauce ones because you can see whats going on inside them.

At crazy tarts or kmart or wherever…..buy a cheap coffee grinder. bout 10 bucks….grind up some flakes in that.

Set up a scale in the shed. Stick the transparent mayo bottle on it with the lid off. stick a funnel on the open end. zero the scale. pour the ground shellac into it. Around say 40grams of shellac. And to get the right 'cut', so the shellacs quite thin (the secret to shellac, which is about a 2pound cut) I multiply the grams of shellac by 6 and thats the amount in MILLILITRES (not grams) of regular metho (don't need pure stuff) I pour into the funnel……e.g. if 40 grams of shellac goes in, I stick 240ml of metho in.

Then lid on the mayo bottle (with nozzle closed). Shake the out of it. and let it sit.

Its ready simply when you look through the clear bottle and see no clumps left. Could be a few hours or overnight. Just keep agitating occasionally. The coffee grinding really speeds things up.

Then go for it with plenty of raking light to watch for build lines. If your getting build lines its going on too thick. Try and smooth them out before they harden (You've got like 10 seconds). Some blokes brush it on in one hand then have a pad in there other, so they can build it faster. The pads just used to smooth out any heavy build from the brush.

Your final coats done with pad thinned down further. Sometimes I just squirt a little meth straight into the pad after the shellac squirt.

etc etc etc

I think I got all the gramma and spelling problems. Editted the bloody thing 4 times.

2cents worth. Just an opinion.

[ubeaut]

Sounds like your shellac may be the problem. Where did you get it and how long have you had it?

If the shellac is fresh or has been stored correctly then it should fully dissolve in 100% metho within 1 hour, 2 hours at the outside. A little longer with 95%. If it takes overnight or a day then either the shellac or metho is no good and you may not get the best result when the shellac is eventually used.

Old or badly stored sellac flakes will tend to look a bit like soggy cornflakes in the metho and won't fully dissolve. It will not really help to grind it because if it's no good it's no good. However, using non industrial metho (stuff off the supermarket shelf) will make the shellac look much the same (soggy cornflakes).

Cheers - Neil

[FenceFurniture]

Sounds like your shellac may be the problem. Where did you get it and how long have you had it?

If the shellac is fresh or has been stored correctly then it should fully dissolve in 100% metho within 1 hour, 2 hours at the outside. A little longer with 95%. If it takes overnight or a day then either the shellac or metho is no good and you may not get the best result when the shellac is eventually used.

Old or badly stored sellac flakes will tend to look a bit like soggy cornflakes in the metho and won't fully dissolve. It will not really help to grind it because if it's no good it's no good. However, using non industrial metho (stuff off the supermarket shelf) will make the shellac look much the same (soggy cornflakes).

Cheers - Neil

Thanks for your response Neil. Both lots were given to me so I have no idea of their ages from retail supply or manufacturer - the darker flakes came from China (I'd be pretty sure), and the pale flakes came from India (I think), refined in Germany and sold from the USA. I think the dark flakes came to me in an airtight plastic bag whicj I decanted into a plastic jar (a good one) about 8-12 months ago. I only received the pale flakes about a month ago, and they were in a very dodgy clip top bag that would no doubt have been punctured by the large sharp flakes. I subsequently put them into a vacuum packed bag (thicker plastic too) with just a little bit of air to stop the puncturing.

On the off chance that the first lot of 95% metho (Diggers) may have been stale I purchased a new bottle for the second mixing but it made no difference at all (which would indicate that the first half-empty bottle that was something less than a year old, was ok). When I purchased the second bottle the shelve was absolutely rammed with them, so they've either just restocked with a fresh supply.....or they never sell ANY.

Grinding it up did help to the extent that it got to the maximum it was going to dissolve a fair bit quicker, but overall I'd say that there was still about 75-80% of the first amount of sludge - just finer sludge.

Overall I believe you're spot on with your assessment that the flakes are stale from poor storage - this is where I was heading when I first posted the thread. I doubted that the 95% Meths was the problem, and that only leaves one other ingredient. Even for me it couldn't have been poor technique - far too simple.

I'm yet to test either of them on timber, but that may be inconclusive as it could all to easily be poor technique in that process. Shellac application is something that I have to do "rather a lot" of practice on.

[Xanthorrhoeas]

As I don't use flake shellac (I prefer button shellac) I can't say that I have had your experience. Shellac is a complex organic, but has proven stable for hundreds of years on furniture (as a finish). However, methylated spirits is a very variable product indeed. It is hygroscopic, which means that it absorbs water from the atmosphere. That means it can have a lot of water in it and water and shellac don't mix. My two cents worth.


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[ubeaut]

Shellac is hellishingly expensive at the moment. What cost $80,000 3 years ago is now around $300,000. This is a world wide problem due to crop failures. Anything from USA even via Germany would be the same and may well be a few years old.

If you want to try shellac flakes I suggest you buy locally from U-Beaut or Woodworks Book and Tool or Carroll's Woodcraft Supplies None will be fresh but I know ours and Carrolls are stored properly (because it's ours) Woodworks don't sell ours but it should also have been stored properly.

One of the biggest problems is storage and if it is sitting on the shelf in a shop it may well have been there for a very long time even years and subject to bright light, heat, etc.

If you get it from us and still have the same problem then it your metho but I doubt it will be.

Cheers

[Uncle Bob]

Interesting thread.
I haven't used Shellac since I was a boy and used it when making coils for crystal set radios.

I had to look it up to see it's properties http://en.wikipedia.org/wiki/Shellac