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My local pharmacy sells 96? alcohol which according to the label consists of 99.9 ml ethanol and 0.1 g CETIPILDRINO CHLORIDE (DCI)

Is this ok to mix up shellac ?

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Richard

I have used it and it seemed to work but can't give a for sure yes or no.

From what I have been told No. I have used some Shellac the last couple of years on some organ parts and all the people that use Shellac say to use DNA (Denatured Alcohol). I also believe that is what is stated on can also. You can get it at anyplace that sells paint it’s cheap.
Jay

[QUOTE=Jay] From what I have been told No. I have used some Shellac the last couple of years on some organ parts and all the people that use Shellac say to use DNA (Denatured Alcohol). I also believe that is what is stated on can also. You can get it at anyplace that sells paint it’s cheap.
Jay[/QUOTE]

Jay,

Getting DNA in Europe and particularly the UK is almost impossible - methylated spirit is the nearest. DNA is I think ethanol with addatives to make it undrinkable.

Richard,

I bet that this stuff will work just fine. Best thing is to try some with shellac flakes and test it out on scrap wood first.

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Use only denatured alcohol or pure grain alcohol!!!!!!!!
a pharmaceutical or rubbing Alcohol is not suited

[QUOTE=Dave White]
Getting DNA in Europe and particularly the UK is almost impossible [QUOTE]

You've got it Dave ! When I couldn't find it in the hardware shops I did a bit of web trawling and found that within the EU that the spec for denatured alcohol varies from country to country ( some add methanol others even seem to add petroleum products !!!!! )

Dave, I see from your website that you french polish your guitars - can I assume that you use methylated spirits ?

As far as I ubnderstood it the stuff usualy sold as rubbing alcohol doesn't work because its only 70% isopropanol with 30% water.

If I try it out on scrap and the mixture sets on plywood can I assume that its ok to use ? Or is there something else I should check for ? (Maybe I'll try and French polish my side bending form )

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Richard

Ethanol, or ethyl alcohol, is 'grain alcohol', although it's often not made from grain these days. What the OP found was one type of 'denatured' alcohol, and should work OK. Methylated spirit is also a type of denatured alcohol, using methyl (wood) alcohol as the denaturant. My Dad's old handbook of chemistry (1937 edition) lists about five pages of formulas for making denatured alcohol, using all sorts of stuff. Some of the additives are poisons (methyl alcohol, nicotine, gasoline), some are irritants (ipicac) or simply render the stuff indigestable (shellac, believe it or not, is a 'denaturant' in high concentrations).

When I was first learning to FP I really had to use all the 'best' ingredients in order to get it to work at all. As I got better, I found I could substitute 'lesser' things and still do a good job. It's sort of like the great guitarist who can make a plywood junker sound good; he had to learn on a good guitar first!

It's usually best to assume that whatever denatured alcohol you are using has some poison in it, and take precautions. I wear plastic gloves when I'm FPing, and try to use good ventilation. Of course, the poison is in the dose: ethyl alcohol will kill you dead if you drink enough of it, as too many stupid frat boys have found out. The basic ideas are not to take anything for granted, and to limit exposure. Other than that, the only way to find out if some particular thing will work for you is to try it.

Methylated spirits is ususlly 95% Ethanol and 5% Methanol. It works fine for French Polish shellac. Denatured alcohol (DNA) is usuually 95% Ethanol with 5% denaturant, sometimes the denaturant is methanol, sometimes something else toxic. Unless the can specifically says it is for mixing or thinning shellac, I would not use it as sometimes the denaturant is nasty stuff that I would not want on my hands. Paint stores sell DNA here in the states.

I have used "Everclear", available in spirit shops, which is as pure as distillation can make ethanol (96% ethanol with 4% water). Ethanol forms an azeotrope with water and it cannot be made 100% pure by distillation unless a chemical "azeotrope breaker" is added, or a chemical drying agent is added and then removed. Everclear works OK, but it seems to takes longer for the shellac to get tough and cross-link (up to a month or more if you body the shellac too much)

The best in my opinion is lab-grade USP pure Ethanol. Not toxic, but tightly controlled and unavailable unless you have access to a lab - I used to work at a lab and would get it there. It will suck moisture out of the air however, as will DNA, so I do not French polish when the humidity is over 50% .

[QUOTE=Cachalote] My local pharmacy sells 96? alcohol which according to the label consists of 99.9 ml ethanol and 0.1 g CETIPILDRINO CHLORIDE (DCI)

Is this ok to mix up shellac ?
[/QUOTE]

Chloride? this would worry me I thought most Chlorides were costics like Chlorine

MichaelP wrote:
<<I thought most Chlorides were costics like Chlorine>>

Sodium chloride?

Chlorine tends to have an acid reaction; it's a oxydizer. Think HCl= hydrochloric acid. Caustics are alkalis, reducers, like sodium, in NaOH, sodium hydroxide. In each of these the element in question has been somewhat balanced by a radical. If you combine the two radicals above you get HOH= dyhydrogen monoxide, or hydroxyl acid, 'The Invisible Killer'. It's found in acid rain, and all cancer tumors, and is used so widely by the military in secret weapons research that it is piped into the facilities where that goes on. Many people die each year from inhaling the stuff. It is also highly addictive. Talk about your dangerous chemicals!

Daves right it's not possible to buy DNA in the UK nor pure grain alchohol, both illegal to sell to the private individual. 99.9% of professional French polishers here use ordinary Methylated spirits and they work just fine,. If your restoring an early Georgian sectretoire believe me you wouldn't risk using a duff alchohol in your French Polish. The other 0.1% get the train across to France and come back with bottles of 'mineral water' that contains pure claer DNA.

I'm lucky however, in that as I have the laboratories of a whole University at my disposal I use pure Ethanol! (Just don't tell the Dean )

My last one however, was FPd using the Liberon pure Blonde de-waxed shellac straight from the bottle and it is fabulous stuff. I just used the ethanol on my pad, and for glazing etc.


Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

[QUOTE=MichaelP] [QUOTE=Cachalote] Chloride? this would worry me I thought most Chlorides were costics like Chlorine[/QUOTE]

Point Taken Michael. It seems that Cetilpiridinio Chloride is a disinfectant so I'll keep on searching to see if I can find anything better ( I'm begining to think I should have stuck with my original idea of just using tung oil !!! )

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Richard

[QUOTE=Cachalote] [QUOTE=MichaelP] [QUOTE=Cachalote] Chloride? this would worry me I thought most Chlorides were costics like Chlorine[/QUOTE]

Point Taken Michael. It seems that Cetilpiridinio Chloride is a disinfectant so I'll keep on searching to see if I can find anything better ( I'm begining to think I should have stuck with my original idea of just using tung oil !!! )[/QUOTE]

I wonder if chlorides in a finish might be a bad idea, because of the bleaching/oxidation potential, which could affect several aspects of the instrument. I am not sure what this material actually is but the "piridine" part of the word reminds me of pyridine, which is a benzene like solvent and used as a denaturant for Ethyl Alcohol and antifreeze. Nasty stuff if this is what is in your denatured alcohol!!! Good luck!

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"Building guitars looks hard, but it's actually much harder than it looks." Tom Buck

[QUOTE=Cachalote] [QUOTE=Dave White]
Getting DNA in Europe and particularly the UK is almost impossible [QUOTE]


Dave, I see from your website that you french polish your guitars - can I assume that you use methylated spirits ?


[/QUOTE]

Cachalote (Richard?),

Mostly I use the Liberon pale blonde ready mixed product that Colin mentioned and use methylated spirit as the "alchohol" drops that get added to the muncea in the relevant parts of the process (plus walnut oil). The methylated spirit, however, is tinted blue. A luthier that builds classical guitars told me that mixing the shellac with meths can result in a slight blue tinge to the finished FP and he used the "away day to France" technique Colin refers to .

I bought a bottle of similar stuff to what I think you are talking about on holiday in Andalucia when one of the kids grazed their foot. The bottle contents described it as 96% alcohol (etilico - which I assume is ethanol)together with Benzalkonium Chloride (0.1%). One of these days I will mix it up with some shellac flakes and test it out on scrap to see what happens.

I usually wear latex gloves when I FP - largely to stop me greasing the guitar surface if I touch it by mistake, so Alan's advice is good. but for stuff sold in a Chemists/Pharmacy I wouldn't be that fearful of getting some on my skin.

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

what ever the denaturant, whether methyl alcoho or others such as toluene, etc., they are not good for you. that is why they are used as a denaturant, to make you sick if you drink it.

as colin says, the purer your alcohol the better for french polish. he is luck to have the access to pure stuff from the uni. my nearest and dearest is a chemistry teacher so i am lucky as well.

i have no idea what the chemical mentioned is. why not ask the pharmacist; he is a chemist after all.

everclear, or similar, if it is legal in your state, is the best usually available to the public.crazymanmichael39014.7664930556

[QUOTE=Dave White]


Cachalote (Richard?),

Mostly I use the Liberon pale blonde ready mixed product that Colin mentioned and use methylated spirit as the "alchohol" drops that get added to the muncea in the relevant parts of the process (plus walnut oil). The methylated spirit, however, is tinted blue. A luthier that builds classical guitars told me that mixing the shellac with meths can result in a slight blue tinge to the finished FP and he used the "away day to France" technique Colin refers to .

I bought a bottle of similar stuff to what I think you are talking about on holiday in Andalucia when one of the kids grazed their foot. The bottle contents described it as 96% alcohol (etilico - which I assume is ethanol)together with Benzalkonium Chloride (0.1%). One of these days I will mix it up with some shellac flakes and test it out on scrap to see what happens.

[/QUOTE]

Dave, I think that the Liberon we now use is as good as anything that I have mixed up in the past, even using the purest flakes and pure ethanol. Even though I have got access to Ethanol, I will still carry on using the Liberon, and just as you do use the alchohol on the pad. In the University maintenance department there is a full time professional French polisher and he gave up mixing his own stuff some years ago and also uses the Liberon stuff from Axminster.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

At lunchtime today I went to a couple of paint stores.

Both stock liquid shellac and both offered 96% alcohol with Bitrex and Cetilpiridinio Chloride as the correct thinner.

It would seem that the stuff from the pharmacy is the same but without Bitrex ( which appaently is there to give a foul taste ).

I'm gonna mix up a small amount and try it out on scrap at the weekend.

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Richard