Official Luthiers Forum!

I'm probably a little too nonchalant when it comes to dealing with a lot of the products we use in guitar building. I often hear that we should be careful with this or that, but I'm not exactly sure what the most obvious dangers are for any given product. The back of the cans read like a pharmaceutical advertisement, with dozens of potential dangers.

So I'm wondering if people would be willing to help compile a quick list of the product and the main danger, for everyone's safety and benefit.

EX: denatured alchohol - be wary of breathing fumes, and igniting it with a flame.

I, for one, would be most appreciative.

_________________
Ken Mitchell
Durham, NC

+
I spray varnish, which is relatively begnin. The chemicals I use for this process are also relatively begnin, namely, acetone, turpentine.

I also seal with shellac, cut with denatured alcohol.

I know that Acetone is basically harmless, same with denatured alcohol. They are flammable, so care must be excercised with regard to that.

Turpentine is a bit of an irritant, but people used to eat the stuff, so it can't be that bad. Of course, I take care to inhale as little as possible when using, and especially spraying.


Things that you really want to avoid are things that contain stuff like Benzene (cancerous) and other hard-core chemicals. These are found in great quantities in Nitro Lacquer. I have a can of the stuff, and the odor knowcks you over upon opening the can. The can lists the ingredients, I looked them up once, and it kinda freaked me out.

Anyway, I try to stick to Turpentine, Denatured Alcohol and Acetone. I only use real paint thinner to clean my gun after each guitar.

Be safe out there!

So as far as al list...

Benzene - Avoid due to it's cancerous (leukemai) nature. Common in solvents and finishes.

And however tempting it may be, DON'T DRINK IT.

Some of the worst ailments are caused by wood dust. Ask John Mayes. Some are worse than others but we tend to underestimate that fine particulate.

Here's a bit of a list.http://www.hobbywoods.com/wood_toxicity.htm

Acetone is not harmless! From the MSDS:
"The substance is toxic to central nervous system (CNS). The substance may
be toxic to kidneys, the reproductive system, liver, skin. Repeated or prolonged exposure to the substance can produce target organs damage."

Lacqer thinner, Naptha, and most other light distillates are nuerotoxins as well. This information can easily be found by downloading a copy of the MSDS (material safety data sheet) either from the web in general or preferably from the manufacturers site. That paper will list not only health effects but all other hazards from use or spills including possible reactions with other items, flammability and flashpoints, proper storage, etc.. I would suggest you download a copy for every chemical you use and read through it. I now suffer from kidney disease and often wonder how much of it is due to a lifetime of cavalier occupational exposure to these type of things. I take my health safety seriously these days and rarely even open a can of aromatic spirits without vapor protection. And yes wood dust is listed as a carcinogen, so I guess I have lung cancer to look forward to as well

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Ummm... I'm the last one to claim expertise when it comes to chemical issues but my understanding is that Denatured Alcohol is not benign....you should be careful not to breathe too much, and shouldn't get it on your skin. By definition it's toxic.

I'm also very careful with epoxies. My understanding is that the hardener is bad stuff - be careful with fumes, and keep it off your skin. Finally, sawdust is a carcinogen. Yeah, probably not an issue for us weekend warrior luthiers, but repeated exposure without dust removal and masks is a bad idea.

The hazards of denatured alcohol depend on how it's denatured. Many now have ~50% methanol which is very toxic. For example, Kleanstrip SLX:
http://www.rockler.com/tech/RTD20000136AA.pdf

They also sell a "Green" version which is better at 90% ethanol, max 10% methanol:
http://www.rockler.com/tech/RTD20000423AA.pdf

Those also have methyl isobutyl ketone, but I don't know how it compares methanol for toxicity. I'd like to find DNA with just ethanol and isopropanol or similar.

_________________
David Malicky

I think you guys are being a bit overdramatic.

Water will kill you if you drink 8 gallons. Air will kill you if it gets in your bloodstream. Sugar is toxic, ethanol is toxic, but we consume both in large quantities (sometimes together!)

Humans make acetone in their bodies, and eat it in the foods we consume. We also wash off our nail polish with acetone. Acetone is listed as an ingredient in food additives...go figure.

Compared to something like Benzene, Acetone is like water.

The MSDS for acetone puts the qualifier "may" in front of every possible symptom, all of which sound like symptoms someone would have if they drank too much alcohol.

Studies tell of giving mice 50,000 ppm of acetone(5%) in drinking water for 13 weeks, and showing no signs of neurotoxicity.

Now, we aren't in our shops drinking acetone...I don't worry about getting a bit on my hands, or putting a few teaspoons into my varnish.

That said, we should always be careful with anything in the shop. I should have used a better word than begnin, or perhaps added "relatively" before.

My point is that I don't worry about getting a little acetone, DA, Turp on my hands, but I definately dont go washing my hands with paint thinner, or MEK, or Benzene.

http://www.epa.gov/iris/subst/0128.htm

•Neurotoxicity and Developmental Neurotoxicity. The neurotoxic potential of both acetone and isopropanol, the metabolic precursor of acetone, have been extensively studied. These studies demonstrate that although exposure to high doses of acetone may cause transient central nervous system effects, acetone is not a neurotoxicant. A guideline developmental neurotoxicity study has been conducted with isopropanol, and no developmental neurotoxic effects were identified, even at the highest dose tested. (SIAR, pp. 1, 25, 31).

http://www.dow.com/productsafety/finder/acetone.htm

From the above DOW page...
Health Information

Acetone has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or breathed. Breathing high concentrations (around 9200 ppm) in the air caused irritation of the throat in humans in as little as 5 minutes. Breathing concentrations of 1000 ppm caused irritation of the eye and throat in less than 1 hour; however, breathing 500 ppm of acetone in the air caused no symptoms of irritation in humans even after 2 hours of exposure. Acetone is not currently regarded as a carcinogen, a mutagenic chemical or a concern for chronic neurotoxicity effects.8

Acetone can be found as an ingredient in a variety of consumer products ranging from cosmetics to processed and unprocessed foods. Acetone has been rated as a GRAS (Generally Recognized as Safe) substance when present in beverages, baked goods, desserts, and preserves at concentrations ranging from 5 to 8 mg/L.9 Additionally, a joint U.S-European study found that acetone’s "health hazards are slight."10

An extensive study was also conducted on "reasonably anticipated children’s exposures to acetone" from commonly found items such as the solvent in nail tip remover, nail polish remover, spray paint and spot remover. The conclusion was that acetone exposure from a child’s environment and from consumer products is unlikely to pose significant health risks. It was determined that 90 percent of acetone found in children was naturally produced in their bodies.11 The rest came primarily from natural food sources, such as onions, grapes, cauliflower, tomatoes, milk, cheese, beans and peas, as well as from mother’s milk.

OK, So I got home from work, read this thread again...

I don't want to seem like I advocate being unsafe with chemicals. I've seen a guy die (quickly) from leukemia, everyone supposed it was from his years working some military job messing around with barrels of benzene. There's some bad stuff out there.

This is a great thread and a great thing to keep in mind when working in the shop. We all should be cognizant of the amount of chemicals we use, and in what fashion we use them. I was just out working on a rosette, and I was outta 50/50 shellac and Denature alcohol. As I mixd up a new batch, I thought of this thread. Don't pour it down the drain, or off in the dirt. That stuff (methanol) is nasty. No need to send it to the bay.

Anyway, my point is that there asre some really nasty chemicals in the biz, and some not so nasty...I like acetone, it works well, and is "relatively" begin, when used correctly.

Let me, if I may, make a list of things you should be extra careful with:

Nitro Lacquer
Paint thinners
Cyanoacrylate glues

Things you should exercise caution with (and not drink), but use knowing they probably won't give you cancer as a hobbyist:

Denatured alcohol
Varnish
Turpentine
Acetone
Everclear (liver cancer!)
Oil finishes

Gold Shield Distributors in Hayward, CA, sells a 190 proof denatured alcohol that is just ethyl alcohol and isopropyl. Their minimum order is 5 gallons, and shipping is expensive because alcohol is flammable. Their prices are good. 5 gallons is about $85. The problem with isopropyl is slower drying time. You can French polish with pure isopropyl, but it takes forever to dry. I haven't used the Gold Shield denatured, but Haiying Jiang uses it exclusively. She French polishes 2-3 guitars every week, and they're ready to put in a case and ship 17 days after she starts finishing. Apparently the isopropyl content doesn't slow drying enough to matter.

For several years, I've been using SDA 23A, which is a denatured alcohol that is regulated by the federal government. That means the composition is guaranteed. That also means that you can only buy 5 gallons per year, unless you're willing to wade through a swamp of paperwork and inspection. SDA 23A contains ethyl alcohol, less than 5% water, and about 7% acetone. It dries very quickly, and works well for French polishing. I've been buying it from Remet Corp. in the L.A. area, but their prices have been going up and up. Gold Shield Distributors also carries SDA 23A. It's about the same price as their regular denatured. I'll be buying from them for the foreseeable future.

I'm no chemist. My understanding is that acetone in itself has a low toxicity. Its danger lies in its ability to dissolve things, and carry them through your skin. What things? Maybe sanding dust from "nickel silver" frets? I don't pretend to know. Hopefully, some amateur luthier toxicologist will straighten us out. Cyanoacrylates have their own issues. They are toxic, or at least sensitizers http://www.ncbi.nlm.nih.gov/pubmed/15128170. (See also Don Teeter's Vol. II.)

I'm guessing sanding dust is the biggest threat. I'll add: buffing dust. Cotton dust has a long association with emphysema. Look it up. Also Melville's "The Paradise of Bachelors and the Tartarus of Maids" .

I'm not a "the sky is falling" kind of guy, but I do advocate knowing what you're messing with, and taking the needed precautions. A client of mine is an insurance inspector who inspects garages and body shops. He has extensive knowledge about chemical hazards and precautions, but also has common sense. I have him look at the MSDS for stuff I use and tell me what precautions to use.

There's stuff that alot of people think are safe that concerns me.

1. Water borne finishes. They're not flammable, but they do contain toxins. Proper safety equipment, as well as proper disposal of waste is important, just like it is with other finishes. It also concerns me when people use waterbornes to be enviromentally friendly, but wash their guns out with denatured alcohol, and acetone, then dump it on the ground, or spray alcohol through their gun to clean it, but think they aren't messing with flammable stuff.

2. UV cured finishes. Vinyl Benzene is dangerous, and it contained in every UV cured finish I know of. I get the impression that people think UV cured polyester is safe since you're not using the chemical catalysts. (Cobalt, and MEKP, the catalyst aren't very hazardous) I also believe the UV lights carry their own hazards.

3. Tru-oil. I suppose it isn't VERY hazardous, but it troubles me when I read about someone applying it , with their finger, inside their house.

4. Epoxy??? I don't use epoxy, and I'm not knowledgable with it's hazards, but I believe there's all kinds of epoxy, with different levels of danger (????)

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

there is a difference between a consumer product containing small amounts of a chemical and the occasional exposure it involves and standing at a workbench holding a rag soaked in it and inhaling the vapors on a regular basis. Drinking water is permitted to contain lead and arsenic as long as the percentages are low enough.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Eric, Thanks for the leads! Those sound great.

_________________
David Malicky