What's in your DNA (denatured alcohol)

[Bill Bukovec]

So if it says denatured alcohol, it must be mostly alcohol (the non-toxic kind), right?

Thanks to a shellac class I took at Woodcraft, I found the answer is no.

The SLX denatured alcohol (made by Kleanstrip) that I have is 50 - 55 % methanol.

I will still use it (I have a full gallon of the stuff) but I will treat it as a poison as opposed to something non-toxic.

The amount of methanol came as a shock to me so I thought I would pass the information on.

Bill

[Mel Fulks]

Denatured means "made poisonous ",would probably be better for containers to just be marked in that way. It's only purpose is to allow the sale of alcohol for shop type uses without the high taxes of drinkable alcohol.

[Steve Schlumpf]

I use Sunnyside DNA that I get from Menards. I have been happy with it.

There is an old thread in the Neander forum on this very subject and it may shed some additional light on some of the contents. Alcohol Content (http://www.sawmillcreek.org/showthread.php?154237-Alcohol-Content-for-Brands-of-Denatured-Alcohol)

[Kyle Iwamoto]

Okay, for the uninformed, (me) what's the difference as it pertains to shellac? I just bought the stuff from the BORG, and it seemed OK...... Maybe that is why my results were just okay...

[Mel Fulks]

Some have some water and just won't dissolve the flakes,even those can be used for a little thinning. The DNA made primarily for shellac is usually a mail order specialty item,and expensive.

[Hayes Rutherford]

Mel, the Sunnyside that Steve mentions and Sherwin Williams makes 190 proof that is good for shellac. At one time I had heard they were 10% methanol but might be wrong. I use grain alcohol for shellac which is costly but no poison worries. Have never soaked anything in DNA .

[Mark Kornell]

Kyle, there is no difference in the end result. All the alcohol, be it methanol or ethanol, flashes off and leaves behind shellac solids.

However, the alcohols do have somewhat different working properties.

Ethanol is safer, flashes slower, and dissolves flakes more readily.

Methanol is more hazardous to use, flashes faster, and can take a while to dissolve flakes.

As it is hard to come by ethanol (in the industrial-use form, at least) in Canada, I use methanol. To deal with the hazard issue, I wear full clothing and apply in a spray booth with good ventilation.

The faster flashing can be used to good effect in a spray application, but when I need slower flashing, I add a 1/4 tsp or so of natural turpentine to my spray cup. If you were brushing on, you'd probably want to slow it down. I've had no issues with fast flashing when padding, though.

And, to get flakes to dissolve quickly, I grind them in a coffee grinder. Fairly coarse works, no need to go for an espresso grind.

[Rich Aldrich]

These are thinners and evaporate. There should be no residual left on your product so it shouldnt poison the end user. I guess it can "poison" the person applying it. I use it for soaking wet rough turnings all the time. I let my pieces dry for a minimum of 30 days.

I used to work for a company where we used MEK and MIBK for paint thinners. That stuff is terrible for the person applying it unless you are in a spray booth with lots of air flow and all of the correct PPE. I starting working with this stuff 6 months prior to when MSDS had to be availble to all. I left the company not long after the MSDS came out. The company had literally no respect for us, IMHO after reading the MSDS.