Face shield art would be nice, but... good design would be better.

[underdog]

I read the latest AAW newsletter this morning.

I was intrigued by the face shield art, there are possibilities there. Dunno if I want the kind of artwork that goes on welding helmets though.

My thought was that I would rather that some manufacturer did extensive research and began making a PAPR product that was:

1) reasonable in price
2) had enough power to deliver the proper amount of air to keep breath moisture at bay in winter, and heat away in summer.
3) filtered well.
4) was lightweight
5) good visibility
6) good protection
8) fully adjustable (like the Bionix)

I've had two PAPR units and eventually gave up both because they wouldn't deliver the air, or were too uncomfortable. I've not tried the 3M product, but holy moly they're expensive. I thought the Trend was expensive at $300+.

You'd think someone would come up with something...

 

[Brian Libby]

Yes the 3M PARR is expensive but it does work well, I am sure David Lancaster will agree.

 

[Bill Boehme]

The 3M PAPR units are expensive for individuals, but they were designed for industrial use ... and priced accordingly. They have also undergone qualification testing to demonstrate that they comply with the requirements of applicable industrial safety standards which is something that isn't likely to happen with a consumer product with a very limited market.

The Trend Airshield Pro has a filter element that meets an EU standard for particulates and the face shield meets ANSI Z87 requirements, but there has been no assembly level compliance certification for respiratory protection as far as I know unless there is for the European market. It seems to be fairly good, but a friend has one and quit wearing it because he found it too uncomfortable to wear for more than a short period.

I am glad that I bought my 3M Airstream when I did about 8 years ago. Back then, they were probably half or less of today's cost. It is unbelievable how the cost of replacement parts for the Airstream have skyrocketed. The blower used to be expensive at just over a hundred dollars, but now it is well over $300. Same thing goes for the battery. I had a bunch of HEPA filters, but am down to just one spare. I looked at the cost of those and they have nearly doubled. But on the other hand, I really do like my Airstream and can comfortably wear it all day long. I can see how someone looking at the current cost of those things would almost have cardiac arrest. However, I almost get cardiac arrest when looking at the price of anything related to woodturning -- lathes, chucks, and turning tools have all doubled and tripled in price since I got into turning.

 

[Sean Boyle]

My brother is into restoring furniture and sprays a lot of lacquer he has a system that draws air front outside and is delivered to a nose and mouth face mask via about a 3/4 inch hose that is about 30 ft or a full face shied. the unit looks like a vacuum pump but with larger in and out outlets. If any one is interested I can get more info lake manufacture and price

 

[Andy Chen]

Jim, I wore a Trend Airshield for 6, 7 years and basically wore it out. Instead of getting the same unit I then upgraded to their Pro version 3, 4 years ago and was totally dissatisfied with it. (The main reason for the dissatisfaction was the weight distribution and despite what others say, I just could not adjust it to balance.) I finally held my nose and paid what I thought was an obscene amount of money and got the 3M Airstream. Now I wish I had done that when I bought the Airshield Pro and applied the $400 to the Airstream. For starters, the Airstream has a HEPA filter (0.3 µm) and the Trend PAPRs don't. Although it looks bulkier than the Airshield Pro, the weight distribution is such that it feels comfortable. The seal around the face is better as well. I live in "central" Texas and the humidity is rather high but I have never had any fogging problem on my reading glasses or the face shield even in the 108° F environment 2 years ago.

Now, you think it is expensive, the $800+ (up to ~$900+ now) I spent on the base unit which includes a rechargeable NiCd battery pack, doesn't even include a battery charger. The "smart charger" that everyone advised me to buy would have added another $130. However, what is your health worth? I know someone in the club who has COPD. It may not have been caused by breathing in the dust, but that surely would exacerbate the problem. As Bill pointed out here, what is not expensive in woodturning (or any other hobby for that matter)?

Now if you should decide to buy the Airstream, you can save some money and in the meantime make it better by replacing the NiCd battery pack with a Li ion battery pack. Alan Zenreich had some excellent info on this subject: http://www.aawforum.org/vbforum/sho...-or-BreatheEasy&highlight=Li+ion+battery+pack.

 

[Bill Boehme]

I've been intending to make some measurements to determine voltage under load and source impedance for my 3M battery. Perhaps I will get a "round tuit" tomorrow. Currently, I have it charging after using it most of the day. I am attempting to come up with a rough order of magnitude comparison of cost of the 3M Ni-Cad battery vs. a Li-Ion battery. While it might seem like a no brainer, I recently discovered that Li-Ion batteries (or at least some of them) have a very limited life of about two years regardless of the amount of use. They are also somewhat dainty when it comes to heavy duty use. If the level of stored charge is allowed to drop below a critical threshold, internal protective circuitry automatically EOL's the battery because of a high probability of explosion from overheating caused by cell reversal. They also require the used of smart chargers.

Even though my 3M Ni-Cad battery is eight years old, it still has the capacity to run between seven and eight hours on a charge before it starts slowing down. I would be interested in the Ampere-Hour capacity of the 5 volt Li-Ion battery packs. Also, if anybody with the Li-Ion batteries has the ability to make some voltage measurements, I would be interested in V[SUB]OC[/SUB] (open circuit voltage) as well as V[SUB]L[/SUB] and I[SUB]L[/SUB] (voltage and current under operating load) for a freshly charged battery pack as well as the same parameters after four hours of continuous use. Given the age of my 3M battery, it isn't exactly representative of nominal performance parameters, but it's what I have and (crossing my fingers) hope that I won't need to buy another one in the near future.

 

[Andy Chen]

Bill, I can talk about theoretical stuff to death but what matters to me is whether in practice things work. The only thing I know is that the 12,000 mAh Li ion battery pack that I have works great. It lasts all day and then some. As to all the jargon you talk about, as long as I have enough air flow, I don't really care about.

One cautionary note though, not all these Li ion power packs are created equal. After my success with the first one, a friend found one online (no name brand) for less money but greater power storage (13,000 mAh), and same 5 V 1 amp and 2 amp outputs. I said sure, order me one. I just got it in this week. Unfortunately, it does not work with the Airstream. It does work with smart phones and tablets, though. So, that's what I'll be using it for.

You can get a 12,000 mAh Li ion battery pack for ~$40, whereas the NiCd battery pack from 3M costs ~$280. Even if like Bill says, my Li ion battery pack dies in 2 years, I can buy 7 of these for the cost of one NiCd, and I will have a 14-year service. I have a brand new 3M NiCd battery pack and I am happy to make a great deal for you if you want it, Bill.😀

 

[Bill Boehme]

Thanks, Andy, you have answered the things that I am concerned about. Generally speaking, the stated Ampere-Hour rating of a battery isn't what you can get at the rated voltage and current so I was primarily concerned about the air flow slowing down about the time that I was getting my second wind (I know, really bad pun). 😀

You mentioned that you do not use your 3M battery. Is that because of the weight or something else?

 

[Andy Chen]

Thanks, Andy, you have answered the things that I am concerned about. Generally speaking, the stated Ampere-Hour rating of a battery isn't what you can get at the rated voltage and current so I was primarily concerned about the air flow slowing down about the time that I was getting my second wind (I know, really bad pun). 😀

You mentioned that you do not use your 3M battery. Is that because of the weight or something else?

You are welcome, Bill. I am just pleased that the entire system works well for me.

Why not the 3M battery? Simple, I would have had to spend $130 on the smart charger. Between the Li ion battery pack and the power supply, I spent less than have of that. Besides, people always talk about the "memory" problem with NiCd. I have never been able to ascertain that one way or the other, but just another reason not to spend $130. Although I never ran a controlled study, I also think my Li ion battery pack runs the Airstream longer, but takes less time to charge. (Here is another tidbit, or legend, that goes with the Li ion rechargeables like the "memory" problem with the NiCds. If you let your Li ion batteries run "dry", you shorten the life of the batteries.)

Weight was not a consideration for me. Alan Zenreich rigged his smaller battery pack so it would go right on top of his helmet for convenience. I opted for the length of operating time from the get-go. No matter how long the battery will last, eventually you have to charge it up and invariably (as Murphy tells us) it will run out of juice in the middle of the day. Instead of modifying the pigtail on the Airstream by cutting the plug off, I made an adapter cable to go between that plug and the USB plug that goes in the battery pack. (See my post at http://www.aawforum.org/vbforum/sho...eatheEasy/page7&highlight=Li+ion+battery+pack.) In the event I run out of juice during the day, I can just plug the USB cable into the power supply that's plugged into the wall and just keep on turning with the Airstream on.

 

[AlanZ]

The particular battery pack that I show in the video is no longer being produced. However pretty much any 2 amp 5 volt battery would work. Some of the battery packs don't have an on/off switch (not really necessary when recharging a phone or tablet), so I've wired a switch inline, so that I can use any power pack available. I have several different packs, all of them work well.

 

[Bill Boehme]

.... Why not the 3M battery? Simple, I would have had to spend $130 on the smart charger. Between the Li ion battery pack and the power supply, I spent less than have of that. Besides, people always talk about the "memory" problem with Ni-Cad. I have never been able to ascertain that one way or the other, but just another reason not to spend $130. Although I never ran a controlled study, I also think my Li ion battery pack runs the Airstream longer, but takes less time to charge. (Here is another tidbit, or legend, that goes with the Li ion rechargeables like the "memory" problem with the Ni-Cads. If you let your Li ion batteries run "dry", you shorten the life of the batteries.)

OK, I understand. I don't recall exactly what the smart charger cost me eight years ago, but it was somewhere in the neighborhood of $69 extra if substituted for the basic charger that came with the Airstream. I had sticker shock back then, but they say that you get numb to it eventually. 🙄

The memory myth about NiCad batteries is just that ... a myth. However, it has become so pervasive that even many electrical engineers don't question it. The earliest versions may have had a problem, but I have a General Electric Ni-Cad battery engineering application manual from over 35 years ago that stated there was no basis for that concern. About the only problem (which is the case for just about all rechargeable batteries) is letting the batteries sit on a shelf for months and self-discharge will shorten their life considerably.

My information about Li-Ion batteries came from the user's manual for my Wacom graphics tablet. That battery and also the Li-Ion batteries for my Canon 7D have built-in electronics to monitor battery health. There may be some urban myths involved, but they also have more hazard problems that other batteries. Long term storage (two months or more) and over discharging can both lead to battery voltage dropping below the safe-to-charge level.

.... Weight was not a consideration for me. Alan Zenreich rigged his smaller battery pack so it would go right on top of his helmet for convenience. I opted for the length of operating time from the get-go. No matter how long the battery will last, eventually you have to charge it up and invariably (as Murphy tells us) it will run out of juice in the middle of the day. Instead of modifying the pigtail on the Airstream by cutting the plug off, I made an adapter cable to go between that plug and the USB plug that goes in the battery pack. (See my post at http://www.aawforum.org/vbforum/sho...eatheEasy/page7&highlight=Li+ion+battery+pack.) In the event I run out of juice during the day, I can just plug the USB cable into the power supply that's plugged into the wall and just keep on turning with the Airstream on.

I remember you well-made connector. That sounds like something that I would do because I hate to make changes to equipment that aren't reversible.

I would definitely be interested in buying your Ni-Cad battery if you do not plan to use it. I go to Caldwell frequently and while there usually make a visit to Snook which probably isn't very far from you or I could meet you at SWAT if you plan to go this year.

 

[Andy Chen]

The particular battery pack that I show in the video is no longer being produced. However pretty much any 2 amp 5 volt battery would work. Some of the battery packs don't have an on/off switch (not really necessary when recharging a phone or tablet), so I've wired a switch inline, so that I can use any power pack available. I have several different packs, all of them work well.

It's good for you to chime in, Alan. I was wondering if you were checking the forum.

Unfortunately, not all the 5 V, 2 amp battery packs will work. Because the battery pack you had used was not available any more, one of the turners in our club had bought a different one but that one didn't work. He bought a second one and it worked. I bought one just like his second one and it works great. Now, the interesting thing is, I had been plugging the Airstream into the 2 amp outlet, but recently I inadvertently plugged it into the 1 amp side and guess what? It worked just fine as well. I have been doing that for the last two charges and it hasn't made any difference. This battery pack has a switch on it but it only turns the Airstream on. To turn it off I have to unplug it.

Unfortunately, as I pointed out in an earlier post another friend bought me a cheaper one that doesn't even have a brand name on it and it does not work on either the 1 amp or the 2 amp side. It does work with smart phones and tablets, and that's what I'll be using it for.

 

[Andy Chen]

I don't recall exactly what the smart charger cost me eight years ago, but it was somewhere in the neighborhood of $69 extra if substituted for the basic charger that came with the Airstream.

The smart charger is now $130 when purchased with the Airstream. Even the "dumb" charger is $80 when purchased with the AS-400.

I would definitely be interested in buying your Ni-Cad battery if you do not plan to use it. I go to Caldwell frequently and while there usually make a visit to Snook which probably isn't very far from you or I could meet you at SWAT if you plan to go this year.

No, I won't be using it and like I said I'll make you a good deal. My house is only 30 min from Caldwell and even closer to Snook but not in the same direction. Yes, I plan to be at SWAT if we don't connect before then.

 

[Steve Worcester]

I took out the Airstream battery and put in a case for 4 AAs. While the theoretical voltage of 4x1.5 (6VDC) is more than the battery pack, it seems to work fine. After cutting the wires and soldering in the batter cage, I put a piece of Velcro on the side of it to secure it in place.
I am going to try PowerGenix NiZn batteries in them next. They are a bit higher voltage (1.6VDC) designed for high drain devices like a camera flash, and have a great power storage time. Down side over NiCad or others is the recharge time is about 8 HRs. They do have a quick charger though (3HRs.)

 

[Steve Worcester]

My brother is into restoring furniture and sprays a lot of lacquer he has a system that draws air front outside and is delivered to a nose and mouth face mask via about a 3/4 inch hose that is about 30 ft or a full face shied. the unit looks like a vacuum pump but with larger in and out outlets. If any one is interested I can get more info lake manufacture and price

I have one of those I use for shooting automotive finishes, although mine is a soft helmet. Don't think I have seen an ANSI Zx version face shield. But the price of the one I have and adding a face shield, a 3M would be about the same, without the issue of the tether hose.