Mylands

Re: Mylands

>>>After using the polish it still remains tacky I turn it at 1250 . Is it because it's old 1 to 2 years maybe the alchol has evapararted I don't know .thanks in advance Art

Do you mean Myland's Friction Polish? The stuff is shellac-based so I'd throw it out if I experienced anything like that.

I find that it lasts a very long time here but that might be because every time I close the can I purge the air inside, replacing it with argon or nitrogen. (I do that with every finish in the shop.)

BTW, I generally spin the lathe at close to 3000 rpm when I polish it with a tiny strip of cotton cloth. It can get pretty hot and I think it needs the heat to work. Maybe your's could use some more speed?

JKJ

Re: Mylands

I looked it up and it is shellac dissolved in methanol.  Unless the company did something to stabilize the product it will undergo a chemical reaction (esterification) that will make it dry slow, or not at all.  Its advantage over Zinsser Shellac which stabilized,  is the Zinsser solvent package dries slower.  Anyone using Mylands should consider just dissolving up shellac as needed, in methanol if a fast evaporation is desirable.  If the shellac flakes are pulverized in a coffee grinder and added to warm methanol they will dissolve quickly. 

Methanol

For those (like me) who would like to be rid of the highly toxic methanol used to "denature" ethanol, there are several sources for 200 proof ethanol denatured with a bitterant to make it undrinkable.  Cost is about the same as buying the methanol stuff at the big box stores.  Guy I get it from sells (1 gal.) through Ebay, but there are others.

BTW, I use a chopper-in-a-hopper to pulverize my dewaxed flakes.  Dissolves quickly with agitation.

I've been buying isopropyl, but this is good to know.

You don't want to drink it, or rub it all over your body, as some people may, but it's not as poisonous as methanol.  I wear nitrile gloves when I work with any chemicals because they're bad for your skin with long-term exposure.  

Permisible exposure limits

Methanol 200 ppm (similar to toluene), isopropanol 400 ppm, ethanol 1000 ppm.  I choose between them based on the volatility I need.  I would think that for quick drying on the lathe methanol would be preferred.  Isopropanol can be needed when spraying in warm weather.  Unless turning is done in a small closet with the door closed none of these solvents presents a breathing hazard in pen finishing quantities. 

The hazard to skin is stripping oils from your hide and that is not much of a hazard.    None absorb appreciably.  The hazard from all is flammability. 

good to know

Re: Methanol

Methanol is much cheaper than ethanol, so chemical companies use it for denaturing.  Some of the DNA you'll find at retail can have up to 50% methanol.  For finishing, epoxy, and cleaning I use a fair amount of alcohol, so I chose to go methanol-free in my shop, regardless of Recommended Exposure values.  I have found no difference in performance with ethanol containing a bitterant as opposed to the methanol mix.

Years ago I learned how to remove most of the water in alcohols using tapioca.  Yeah, the pudding stuff.  Turns out adding the dry tapioca to the ethanol works because the stuff absorbs the water but not the alcohol.  I then spread the wet stuff out to dry the evaporate the water so the tapioca can be reused.  Takes a full day to get dry.  The "dry" ethanol (and 'rub') dissolves my shellac flakes faster.

who knew?

Or you could make some really good pudding.  ;-)

Re: who knew?

Read this by a chemicals engineer looking to find a cheap way to pull out the water so the ethanol would meet purity stands for motor fuels addition.  It works but in order to scale it up to manufacturing volumes, you'd be cycling rail cars' of tapioca.  Don't know if he ever got it into production, but it does work.

Question

How do you know it works and most important how do know it works after three cycles of the pudding?  I am skeptical that air drying will remove sufficient water from the tapioca to enable it to soak up more from the ethanol. Keeping track of the weight of the tapioca could be used to see how water was absorbed and evaporated at various stages. 

If a chemical engineer was proposing this means of dehydrating ethanol he/she must have graduated last in their class at one of the lesser departments.  It is hardly unknown how to economically dehydrate ethanol on a commercial scale. 

how fuel ethanol is dried

It Works

Used on a new 1qt bottle of 70% isopropanol.  Added the package of tapioca and allowed to sit a day with occasional agitation.  Strained out the wet grain and had close to 24 oz of alcohol left.  Put an open flame to the wet tapioca but got no alcohol flame, so no alcohol there.

Wet tapioca spread out on a baking sheet in the warm sun for a day or two.  Put back in the zip lock bag. 

Also got a reduction in volume with DNA.  Been using the same bag of tapioca for about 5 years.

Why do this?  I was having leveling issues with shellac where some areas of the surfaces were not smooth.  On a hunch that water in the alcohol mix might be puckering the wood grain, I used the process and tried the "dry" alcohol.  Spayed shellac leveled out like glass.  Problem solved.

As I said, I don't know (and kind of doubt) if this was ever used industrially, but it was an interesting article.

Re: It Works

Why not use the 99% isopropyl alcohol instead of the 70%? It is my understanding the 70% is for rubbing and has the water added.

Bill 

This drying agent is readily available

Purchase (ebay for example)  3A Molecular Seives.  The 3A stands for 3 Angstroms, the approximate holes size in the zeolite matching the size of a water molecule. 

Without an analysis for water remaining to prove it works  I remain skeptical that Tapioca will significantly dry 95% ethanol.  Removing most of the water from 70% isopropanol is a greatly different situation.  I don't doubt there will be significant, but not complete,drying.

Never seen

that percentage around my area

this is what I use

https://hand-sanitizer.hand-sanitizer.org/art-naturals-artnaturals-rubbing-isopropyl-alcohol-99-percent-pure.html

Sadly, I can't remember when/where I got it (~3 years ago?), but it was "delivered".  

They might not deliver it to CA, but NJ shouldn't be a problem.  ;-)

What I use

Since most all that I use is the 200pf ethanol, I have little use for isoprop.  I use it as a slight retarder in warm weather by actually prefer pure turps for that.