“methylated spirits or meths is denatured alcohol (ethyl alcohol solution “denatured” by adding methanol)”

I generally use the Liberon shellac flakes with bog standard Meths you can but from DIY stores or Garden Centres. I’ve never had any problems with this approach.
I store the mix in old sauce mix jars and have never had any issues with shelf life – even when I’ve used Meths that’s so old it’s lost the purple color and turned clear.

Meths is DNA. Just buy whatever is available.

I bought a big tank from amazon and it;s fine with shellac: https://www.amazon.co.uk/Barrettine-MMSP005-Mineralised-Methylated-Spirit/dp/B0041WAY1I

Be very careful what you believe on the internet – not all denaturing is the same.

I’ve always interpreted denatured alcohol to be mostly ethanol with percentage of added methanol to make it poisonous.
The Barrettine referenced by Richard is ethanol with propanol and ethyl methyl keytone (check the MSDS sheets). This stuff is denatured with propanol and EMK rather than methanol.

For anyone else here in Canada – methyl hydrate (which is on a lot of shelves) is 100% methanol (generally). Methanol is toxic enough that I looked harder to find something with a low % of denaturing methanol.

Functionally these will probably all act about the same (I’m no expert), but it’s your health – so be aware of the risks of the chemicals you’re using, or *think* that you’re using.

@dglaurent what have you found to dissolve shellac in Canada? I was using methyl hydrates, but am worried about damage to the optic nerve from the vapours. Have you found a suitable ethanol anywhere?

I found denatured alcohol at a local concrete place – https://hardrockdevelopments.com/product/denatured-alcohol-1-gallon/

Apparently they use it for marbling or something when they do decorative countertops. The guy had no clue what I was talking about when I told him I needed it for wood finishing.

The MSDS on the one I bought has it as 95% ethanol, 5% methanol. It was like $45 for a gallon or so if I remember correctly – so not super cheap.

For John Buckley and dude: it’s your life and your risk tolerance. I will copy in a section of the MSDS for the Chemfax Methyl Hydrate however:

Hazard Statement
Highly flammable liquid and vapour. Toxic if swallowed. Toxic if it comes in contact with skin. Toxic if inhaled. Causes serious eye damage. Causes damage to organs (kidney, liver, eyes, and central nervous system) via inhalation, ingestion, and adsorption through skin.

I’ll take the risk on a 5% concentration a little easier than a 100% concentration – your mileage may vary. As I first said, be careful what you believe, even from me – go look yourself.

Same here, I use food-safe alcohol (90% I believe). Not cost prohibitive, with the amounts you normally use for shellac. In Belgium, they add a little ether to denatured alcohol, and I can’t stand that smell.