Metalurgists - Educate Me Please...

[chrisp]

Although not super informational in relation to your specific question this will help clear up some of the terminology being thrown around here.

http://www.safetysocket.com/bd/Products/plating.htm

[RickM]

Anthony, Any recommendations on plating shops in NJ?

I've used Mara in Newark with good results.

[Cobalt]

RickM,

You can try any o f these places. I don't know what you are trying to have plated but give these shops a call and see if they can help you out.

Metal Improvement Co., Carlstadt, NJ 201-935-1800

Advanced Coating Techniques, N. babylon, Ny 516-643-4555

Anoplate Corp, syrecuse, Ny 315-471-6143

L.Ripak Co, Inc. W. Babylon, NY 516-694-1818

These places may be able to help you out. Some just do Anodic Coatings and i am sure they all have minimum charges. You may want to determine what you specificly want done before calling.

I have never used Mara, although some of my customers have. i was told they do good work but can be a little on the slow side.

I hope this helps. If not let me know and I can try to research some other houses.

[IROC]

Cad plating is generally fine as long as the fastener isn't going to subjected to temps greater than 400F (IIRC). The toxic gases aren't emitted until these higher temps.

We weren't allowed to use cad plated fasteners on the stuff we used to fly on the Shuttle (back when NASA had budget and we actually flew stuff on the Shuttle all the time...) for this reason. They were worried about the toxic offgassing of the cadmium in the event of a fire. I would have been alot more worried about being on fire 240 miles above the surface of the Earth, but what do I know...

Mike

[Mike Andrew]

Cad is still very much alive & well in the areospace & defense industries & likely will be for some time to come. Much of the hardware in the field is loaded with mil spec fasteners requiring cad plating. Hence replacement parts are going to be required which require cad plating.
Additionally, cad & aluminum are close on the galvanic chart & therefore, galvanic corrosion is reduced by using cad plated fasteners in aluminum. Not that big a deal in autos but you don't want a fastener pulling out of an aluminum housing at 30,000 feet.
Probably 60- 70% of the MS fasteners in my plant are cad plated & many of the parts we manufacture for our product are too. Plating costs have increased but cad is still available.

[Randy Webb]

Thx Bob for your post. I agree with what you said, and would just add two things:
1. all you guys using solvents to remove the sound deadener from the rear firewall should read the VOC & ventilation/mask comments carefully.
2. The safety stds. are generally based on health effects from acute exposures and without combined effects of different chemicals. So, the health effects could be a lot worse than we think.

Finally, maybe someone can post why Cd plating is better than the Zn plating and when we need to use that sort of fastener.

And, let me remind everyone of Jim Simms post of a glorius silve plated SPS cap screw on another current thread -- $136 each.

[Wayne 962]

Great info in this thread - thanks!

More questions. How bad is gasoline? When changing fuel filters and working on fuel systems, I find it almost impossible not to get at least a little bit on your hands (and sometimes your legs). Once, I dumped a whole lot on top of me when I was dumb enough not to know how to properly clamp a line underneath the car.

I also have a ventilation mask that I wear when working around gas (sometimes). Once I was working on something and I had the mask on (the mask is such that you cannot smell the gas when you are wearing it), and after a while I got really light-headed. Common sense would say that if I can't smell the gas from within the mask, it's blocking it? I thought maybe not after that indicident.

Thoughts anyone? Bob?

-Wayne

[IROC]

Originally posted by Randy Webb
And, let me remind everyone of Jim Simms post of a glorius silve plated SPS cap screw on another current thread -- $136 each.

Heck, I had two bolts on a design I did a few years ago that cost $5000 each.

And...as far as gasoline goes, I was replacing a fuel pump on my car a few years ago and got gas in my eyes. That smarts.

Mike

[banjomike]

Bob S. hit it on the head. I work for an Industrial Hygiene firm. I mostly do asbestos and lead consulting, but cadmium is a side issue that comes up from time to time. The permissable exposure limit (PEL) for cadmium is about 1/10th of the PEL for lead, so it is safe to conclude that Cd is more dangerous than lead. It is a toxic heavy metal, carcinogen, and a reproductive toxin. I would not recommend welding, cutting, or grinding on a cadmium plated metals. I would not worry about handling a Cad plated bolt. Both would produce respirable particles or fumes. I would also reccomend no grinding, cutting, or welding on the yellow zinc, Cromium-6 is nasty stuff (no profession knowledge on Cr-6). While a respirator will reduce your exposure keep in mind that the dust will adhere to your clothing and when you go in and hug you child then they suck their thumb they will be exposed to. If you will be creating dust or fumes from a heavy metal, please use coveralls and launder them separately, and wash your hands, arms, and face well.

Also Bob was right about the volitile organic compounds (VOCs). If the can says use only in well ventilated area, they don't mean open the door. They mean open everything and turn on the fan to move the fumes away from you.

There is a system in place to help educate people about toxic materials. Every product that may have some dangerous property has a material saftey data sheet (MSDS). The manufacturer has to give you a copy for free on demand. Call the cust serv number and ask for one. The MSDS will have all sorts of useful info.

[banjomike]

I don't know a whole lot about gasoline exposure, but I'm pretty sure some of the components are carcinogens. It can be absorbed through the skin.

At any contractor supply store or safety supply store you can buy half face respirators. North is an excellent brand. The facepiece is like $30. You can buy filter cartriges to protect from almost anything you can imagine. HEPA is the filter for particulate or metal fumes. Activated carbon will protect you from VOCs (like gas). These respirators can give you a lot of protection if used right. They don't work if you have facial hair that interferes with the seal of the facepiece.

For changing a fuel filter gloves (like the purple plastic ones), a respirator, and good ventalation would go a long way. If you were a mechanic that had gas on you all of the time, more protective measure would be in order but for the DIYer with the occasional exposure there are greater dangers (like dirving to the parts store).

[Randy Webb]

Wayne, gas contains benzene (or used to, I'm sure it still does) and that is pretty nasty stuff. I'm sure the Calif. state agencies will know a lot about this as they had to study to do that "known to the State of Cali. to cause cancer..." posting law.

I think it will depend on how often you spill it on your skin or breathe the fumes. I would avoid that. Like Bob, as a kid I put used oil on weeds and etc. and swallowed some gas when siphoning... That doesn't mean it is smart to repeat stupid things.

MSDS's are on web sites usually if you want to see one quick.


Ok, now a new poll -- how many people here smoke?
And how many eat organic food and smoke....

[Wayne 962]

Originally posted by Randy Webb
And how many eat organic food and smoke....

Nail on head...

-Wayne

[RickM]

Here's a Data Sheet on Gasoline. Lists most of the ingredients
and effects. http://www.brownoil.com/msdsgasoline.htm
Apparently Benzine is still in use.

Cross reference the list with the capabilities of the filter cartridge to verify protection. Some suggest using a NIOSH/Msha TC 23C or equivalent respirator but others say only a Positive pressure Supplied Fresh air or Self Contained configuration is acceptable.

[Wayne 962]

Originally posted by RickM
Some suggest using a NIOSH/Msha TC 23C or equivalent respirator but others say only a Positive pressure Supplied Fresh air or Self Contained configuration is acceptable.

Indeed, fresh air is the only sure way to go. These systems are thousands of dollars though - UNLESS, someone knows of a good one that is not that expensive? Doesn't seem like it's too technologically advanced: one fan, one filter, one mask, and a long hose.

-Wayne

[RickM]

Originally posted by Wayne at Pelican Parts
Indeed, fresh air is the only sure way to go. These systems are thousands of dollars though - UNLESS, someone knows of a good one that is not that expensive? Doesn't seem like it's too technologically advanced: one fan, one filter, one mask, and a long hose.

-Wayne

Actually, some hobby versions are available at reasonable prices. Here's a popular brand: http://www.eastwoodco.com/shopping/product/detailmain.jsp?itemType=PRODUCT&RS=1&itemID=1789&keyword=34053

and another cheaper one: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=4302189038&category=43617

I've read many DIY articles where some try to use a compressor. Even the Oilless units emit various amounts Carbon Monoxide and other nasty stuff. Not worth the risk.

Hmmm, wonder if I can use my stand-alone HVLP unit?

[Randy Webb]

How about a SCUBA tank?

[Bill Verburg]

Cad plating is also particularly suseptible to corrosion in a seawater(or salty road) environment, it is one of the least noble metals in this regard.

[Zeke]

What's going on, Wayne? Sperm count a little low?

[Wayne 962]

Originally posted by Zeke
What's going on, Wayne? Sperm count a little low?

Actually, quite the opposite (wife prego within 3 weeks off of the pill)...



-Wayne

[First911]

Gasoline is a complex mixture of roughly 200 different compounds. Many of these are added to raise octane and meet air quality requirements (oxygenated fuels).

Benzene is still in gasoline but can't exceed 1% volume by law. Benzene is a carcinogen and very toxic. The permissible amount in your drinking water is 1 part per billion (that's like one American in the entire population of China to put it in perspective).

The other nasty compound and a suspected carcinogen is MTBE (an ether-based chemical). There is approximately 11% MTBE in California gasoline. The government forced the oil companies all to put MTBE in gasoline in the mid-1980's at the cost of billions. Now there is movement to ban this chemical because it doesn't degrade once released into the environment and is very mobile in soil and groundwater. MTBE contamination of the City of Santa Monica's drinking water wells hit the news big in LA a few years back. I can't complain too much about MTBE because its been good business for me as a geologist.

Other nasty compounds in gasoline include: toluene, ethylbenzene, and xylenes. These aren't carcinogenic, but still have health risks.

Randy Webb is absolutely right about the exposure calculations only being based on one chemical. If you're using more than one, there can be cumulative effects. It really can be a 2+2=5 type thing.

Wayne, I wouldn't be too worried about the occassional or incidental contact with gasoline. Take steps to protect yourself the best you can and wash off the area in contact with fuel as soon as you can.

The fact that you felt light-headed means that your respirator cartridges were "full". The nose gets de-sensitized very easily with some chemicals. The cartridges can only absorb so much chemical and you really have to change them out frequently in a closed space.

Instead of trying to rube goldberg some type of respirator to protect you from vapors, I think it would be easier to install or buy a big fan. If you want to go the respirator route, you can buy/rent breathing air in large cylinders from a local welding supply place and connect that to a respirator. To buy the air in the tanks in not very expensive at all. They do that on haz waste sites as the backpack tanks are only good for 15-20 minutes of strenuous work.