Ethyl alcohol and French polishing

[SteveS]

For French polishing, I have previously used methylated spirit as my shellac solvent.  Here in Italy, the nearest substitute doesn't contain enough alcohol to dissolve shellac.  I had to look for an alternative. 

 

I found a supply of denatured ethyl alcohol (99.9 degrees) and its use in French polishing is far better than using meths.  I found that the application of the shellac with the rubber is far smoother, the alcohol evaporates quicker, the tacky phase of the applied shellac is shorter, and the surface hardens quicker than with meths.  I've even not had to resort to applying a lubricant during the polishing phase.

 

Also being clear, with ethyl alcohol there's no risk of a purple colour being imparted to light shellac finishes.

 

What has been your experience of using ethyl alcohol?

 

[Geoff Wooff]

Hi  Steve,

here in  France  it is  very  easy  to  get  ethyl alcohol  of  90° , though  95°  is  sometimes  found  at  hardware  stores.  I  am  currently  using  the  90°  variety  and  feel the  need  for  a little  lubricant  to  aid  polishing-in  but  generally  results  are  reasonable.    Temperature  and humidity  appear to  be  more of  a problem, combined with  the  choice of  rubbing  cloth  giving  fairly  variable  results.  

 

Sounds like  I  need to  search  out  your  99.9 degrees!

[SteveS]

Hi Geoff

 

I found the 90° variety in hardware shops here didn't dissolve the shellac too well - it's mostly used for cleaning, and maybe there are other additives.  It's also coloured red.

 

I bought my 99.9° ethyl alcohol at Amazon Italia, and it's specifically for French polishing.  However, I think a 5-litre container of ethyl alcohol will last me an awfully long time

 

Edited June 16, 2023 by SteveS

[alex_holden]

Ethanol absorbs moisture from the air and also evaporates more easily than water, so if the container isn't well sealed it will gradually become less concentrated.

 

The additives they use to 'denature' the alcohol (i.e. make it poisonous to drink) seem to vary between manufacturers - I've had some that smelled fairly innocuous and another that stank like paint thinner.

Edited June 16, 2023 by alex_holden

[SteveS]

I think that the water content, since it doesn't evaporate as readily as alcohol, remains in the shellac for some time after application, resulting in the shellac remaining soft and tacky.  I guess this then necessitates the use of a lubricant at the polishing stage.  

 

And yes, I'll ensure my containers are tightly closed

Edited June 16, 2023 by SteveS

[David Lay]

Ethanol /Ethyl Alcohol is hydroscopic and will absorb moisture from the air quickly.  Manufacturers distill it to get to 95% alcohol/water (190 proof) easily.  Getting out that last 5% is difficult making 100% ethanol quite a bit more expensive .....and it will quickly become less than 100% after being opened.  Keep your stock in a closed container.  (Also, don't drink it even if it's not "denatured" unless you add at least an equal volume of water.  It will be desiccating your esophagus otherwise.)

[SteveS]

1 minute ago, David Lay said:

 (Also, don't drink it even if it's not "denatured" unless you add at least an equal volume of water.  It will be desiccating your esophagus otherwise.)

I've no plans to drink it - we've got plenty of very good wines in Italy

[Geoff Wooff]

A  good  tip  there Steve,  thanks  for  the  Amazon  suggestion.

[SteveS]

Just now, Geoff Wooff said:

A  good  tip  there Steve,  thanks  for  the  Amazon  suggestion.

Maybe Amazon Italia can ship to France?

[Geoff Wooff]

I  found it  on  Amazon France  but  looking  for it for  a  friend in Ireland too.

[Don Taylor]

You might try your local pharmacy, I saw a 500ml bottle 0f 99.9% in ours a couple of days ago.  I am not sure what it is used for medicinally.

[Łukasz Martynowicz]

Interesting. I didn’t realise, that readily available 99.9% Ethyl is problematic to get in some countries. Here in Poland you can get it in specialised art/renovation supply shops. I don’t know if they deliver outside of Poland, but I guess there might be a chance for EU delivery from here: https://www.art-konserwacja.pl/produkty-pomocnicze-149/

[Łukasz Martynowicz]

2 hours ago, Don Taylor said:

You might try your local pharmacy, I saw a 500ml bottle 0f 99.9% in ours a couple of days ago.  I am not sure what it is used for medicinally.

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