Homemade Head Cement

[John Ski 0]

The first point you need to confirm is that the GOOP version you have is not Styene based (most are now by the way). If the GOOP is a styrene based formulation the only solvent that I am aware of that will actually dilute it instead of turning it into a white glob of slime is PERK (this is modern dry cleaning solvent and is Federally controlled in quantities over 1 oz. contaners.) PERK can be purchased by the ounce from fly shops that carry styrene based head cements.

 

Thanks halcyon

 

Just read the very fine print on the package and there is no mention of Styene. It does say it contains toluene and petroleum distillate... so I'm guessing I'm okay with the Xylol, if I decide to go ahead and try this.

 

Didn't mean to cause such a stir with this question about mixing glue everyone. I hope none is getting fumed over this.

 

 

See what I did there... I made a funny. Thanks again everyone, I really appreciate the info.

 

[EricF 0]

Thanks John, I'm not getting fumed - well, ok, it is my line of work, I love it, and I love to argue.

 

SO:

 

Here is the link to EPA's evaluation of the carcinogenicity of PCB.

 

http://www.epa.gov/iris/subst/0294.htm

 

It was last updated in 1994 (my mistake, I thought it was prior to that).

 

they list 6 rat studies investigating the carcinogenicity of PCBs. Note, however, the table under II.B.2

 

It identifies the number of tumors found in rats based on the dosages in the feed and how that relates to a human dose. We'll take the top two doses at 50 ppm and 100 ppm - parts of the commercial formulation of PCBs per million parts of the diet. To compare, 1 ppm would is the high end for striped bass and large bluefish in the mid Atlantic states. (corrected, original post identified it as low).

 

Let's take the highest dose and their conversion to a human dosage of 1.52 mg/kg/day -for two of the formulations roughly 1/2 the rats studied got cancer. Let's make the math easy and call it 1 mg/kg/day. Assuming a 70 kg man, that would equate to 70 mg/day. The density of PCBs ranges from 1 to 1.6 g/cm3. Again, let's make the math easy and call it 1 - the same as water. There are 3785 grams per gallon, or 3,785,000 mgs per gallon of water - a far cry from 70 mg/day. Lets say your comparison to 5 gallons was over the full exposure period - now, typically assumed to be 30 years of exposure - so, 70 mg/day x 365 days x 30 years = 766,500 mg exposure over the lifetime. Still - roughly 5 fold lower than 1 gallon.

 

You stated: "For a human to be subjected to the level of PCB that the lab rats that served as the basis for the EPA exposure limits for this compound, an adult would have to drink 5 gallons of pure PCB for days on end."

 

I don't see that math.

[flytyer48 0]

My advice is stay away from MEK. If I remember rightly from my Health & Safety auditing days that is a material which defats the skin and breathing it in over a tying bench and having fumes in your lungs. Why not use clear nail varnish. The only problem is the questionong looks when you buy it. "I only use it for glue" - yeah right!

[bowfin47 0]

While understanding John's emotional sentiments, I have spent too many hours in toxicology classes, to disagree with with Eric...

 

With that said, I checked to find that:

 

"Toluene is listed by California's Office of Environmental Health Hazard Assessment as a reproductive toxin that may cause harm to the developing fetus. Pregnant women should certainly not use products containing toluene".... and that "xylene, a suspected reproductive toxin that has shown reproductive harm in laboratory experiments. It is also a neurotoxicant that can cause memory loss on repeated exposure." http://www.leas.ca/toxins-in-household-products.htm

 

But, since I don't live in California, and as there's absolutely zero chance for this 58 year old male to become pregnant, I still use toluene to thin my GOOP!

 

But when I am going to use very much, I do take the precaution of turning on the fan and opening the door... i.e. ventilate the room well... refer back to my opening line! Ha! :hyst:

 

PS

 

Ventilated room or not, I totally agree with the caution to stay the hell away from MEK... now that's some nasty stuff, besides it "kicks" my asthma every time!

[Chuck CV 0]

For what it's worth, I've used a good grade of nitrocellulose-based (read the label) clear gloss cabinet lacquer such as Watco for years. Thins with lacquer thinner, usually available on the same shelf of the paint or building supply stores where I buy the lacquer. A minimum-sized container (quart or pint) will last for years.

 

You'd be surprised to learn how many commercial "formulated expressly for fly tying" head cements are nothing but repackaged lacquer. I'd rather pay $10/qt. than than $1.98 per 1/2 oz.

 

The plasti-things (poly, butyl, etc. again, read the label) tend to separate into a useless goo glob with repeated thinnings - and cease to work well in flies well before that. They're especially good for hair work at first, but have limited shelf life when it comes to repeated thinnings.

 

Lacquer thinner does contain some nasty stuff, but (a) it's diluted, and ( the formula for the thinner does not unbalance the lacquer with continued use. MEK and toluene evaporate too fast, thus adding to their airborne toxicity, and don't work well by themselves for thinning cement.

 

I use a turkey baster or a squeeze-type mustard dispenser to mix the lacquer and thinner at about a 3:1 ratio into a Renzetti-type glass jar with a dubbing needle in the seal cap. More thinner can be added as cement is consumed or thickens. The mixing or thinning goes on outdoors.

 

This jar keeps fumes from building up while tying, unless I manage to spill the contents all over my bench. Fortunately, this hasn't happened for a couple of years...

 

Hope this helps,

 

Chuck