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RFNK
20th April 2000, 01:45 AM
Everyone seems to recommend those really expensive full-shield type dust masks that blow air into your face. Is there any reason why the MUCH CHEAPER cartridge type respirators can't offer similar protection? Any advice would be greatly appreciated; I simply don't have $800 for a dust mask or the steel-reinforced neck required to carry an air pump on my head!

Rick

AlexS
20th April 2000, 09:01 AM
I've used both and found the full mask more comfortable and effective than the cartridge type. The positive pressure of the mask type means that you don't suck dust in around the seal when you breathe in.
If you adjust the head strap properly (at least on the Racal that I use) the weight is quite well balanced and is not a problem.

I agree with you about the exhorbitant price. They were never cheap, but since they've been taken over by a certain sticky tape manufacturer, the price has skyrocketed. I'd like to see some justification for that, 3M.

Gino
22nd April 2000, 12:20 AM
Hi Guys.

I've delt with 3M on many occasions, nothing to do with woodwork and they have always been pricey.
But for your information Triton are working on one of these face masks also, it may pay to enquire with them how much they expect to retail for and when.

Regards

Gino

ubeaut
22nd April 2000, 08:51 AM
G'day Rick

There are cheaper helmets available. You don't have to thave the top of the range. Try the other Racal mask or have a look at the ones that Carba-Tec import from England. It is alright to own a Rolls Royce but a Holden will also get you to the same destination at a much lesser price.

If you are at all concerned about your health you will invest in one of the masks. For long time security there is no substitute. Have a look at this page if you are in doubt as to whether or not you really need one. Healt Hazards & Timber (http://www.ubeaut.com.au/badwood.htm) The alternatives to not having a mask (especially if you do a lot of sanding) are not the best.

Cheers
Neil

JackoH
22nd April 2000, 02:29 PM
I can sympathise with you on your indecision regarding the purchase of a (Racal) 3M dust mask. Starting turning 2 years ago I made do with a respirator but found it to be uncomfortable, particularly in hot weather.Also I enjoy turning red gum but found that I had an almost instant reaction. This took the form of catarhh and a blocked up nose for 24 hours or so after working with it.I have since learnt that red gum dust is highly toxic as are several other species of timber dusts. As they say "it's the dust you can't see that causes the problem". So I bit the bullet and bought a Racal and cannot recommend it too highly. Whilst there is no doubt that 3M are ripping us woodies off, it is still cheaper than paying for a premature funeral, not to mention the pain and suffering caused by emphysema, clogged up lungs etc. My advise would be to shop around you may get a better price than the recommended $850. In the April issue of the Pommie Mag.Woodturning there is a road test of three respirators including the Racal(3M DM4). The other 2 are the Powerlite Airshield and the 3M Airlite.Both of these are less expensive. What Price Health?

Shawn
10th May 2000, 06:53 AM
I have been using a 3M air helmet for about 4 months now and am very pleased with its performance. The only thing I am not pleased with is the cost. I like my health though.

RFNK
10th May 2000, 07:15 PM
OK, thanks everyone! Well, now I have a respirator and a blasted, really expensive 3M Airlite shield with the little fan in it which goes up and down like a roller coaster etc. and, well, I do feel much better after using it. But, now I find that 3M can only supply one grade of filter for it. I'm still not confident that it eliminates the finest dust which is the dust that really does the damage. Any ideas?
Rick

Shawn
11th May 2000, 01:58 AM
The 3m helmet I bought has a HEPA filter in it which is as good as it gets. I purchased mine from airamerica.com. Since I live in the U.S. maybe I am getting a different product.

Shawn

Shawn
11th May 2000, 02:04 AM
I made a mistake. I purchased it from airware america. Their web page is www.mid-web.com/airware. (http://www.mid-web.com/airware.) Hope this helps.

Shawn

Shawn
11th May 2000, 02:09 AM
lets try it again. www.mid-web.com/airware (http://www.mid-web.com/airware)

AlexS
11th May 2000, 09:23 AM
I also have had an Airlite for about 3 years. I've been keeping an eye out for any signs of dust on the inside - especially on the visor, but haven't found any, so I think the filter is pretty good.

A tip - to prevent it being accidentally damaged from lying around, I picked up a styrofoam 'head' - the type of things that jewelers, hairdressers etc. use to display their wares. About $2 at a weekend market. It sits on a dowell and the mask sits on it when not in use.

Yip
14th June 2002, 08:21 AM
3M Airlite Respirator
http://www.axminster.co.uk/default.asp?part=airlite

UK £119.11 excl VAT equals AUD $309.30 plus shipping etc.

cliff cook
14th June 2002, 11:19 PM
I`ve had my Rachel for about 5 years and apart from the price of spare parts (see discussion a couple of months ago on this channel!) i have nothing but praise for this machine.When i bought this machine i had a face like a babies B-- , now i look like ZZ TOP. To make it work proper I`ve run some velcro around the edge of the mask and made a cloth hood that covers the entire head and
shoulders to keep dust out of hair and hair out of quickly revolving work.The old curtains i used look raelly bad but no one see`s me in it so who cares. Cost velcro= $1/mtr Cloth $0 .Very happy
cooky

Bazza
16th June 2002, 08:25 AM
G-day all,

I was in my local woodworking supply shop at Yatala, and was shown a new (to me) dust mask called "Dust bee gone", It looks like a surgical mask and can be washed and reused.

Not cheep at au $66.00 each but was told with care they have a 5 year plus life span.

Has anybody used or seen this mask, and are they an alternative to the powered masks.

I found this website http://www.dustbeegone.com/

Barry

Nuggett
17th June 2002, 12:36 AM
Got a Trend Air Shield at the Brisbane Wood show cost $420 I bought it on the last day of the show just as they were packing up work like a charm. But when I get a new battery I be buying from overseas as these Mongrels charge like a wounded bull! That goes for most of the other accessories!
If you work in a garage that's attached to your house then get proper dust extraction equipment eg air cleaners Dust Filters make sure these are rated at 5 microns or less for the sake of everyone health
Hope this helps

BrianR
17th June 2002, 12:13 PM
I have a Purlite and it works very well, however like most other helmets it has a P2 filter which removes particles down to around 5 microns but the smaller ones are the most dangerous and some of them still get through.

I also have one of those vacuum cleaner sawdust extractor things and it takes a lot of dust too, but when I installed an exhaust fan on the wall immediately above the lathe, there was soon a large dust coloured patch on the wall outside. It brings a new meaning to sweeping the floor when the wife tells you to sweep the wall too.

I reckon you can't make it perfect but exhaust fan close to the lathe is a cheap way to move the fine dust out.

Tim the Timber Turner
17th June 2002, 01:23 PM
Spot on Brian. Its the most cost effective method I have seen, and combined with a personal respirator is the minimum dust protection one should use.


------------------
Some days I turns thisaway, somedays I turns thataway and other days I don't turn at all.

BrianR
17th June 2002, 05:07 PM
Nuggett,

I shared your battery blues as the Trend and the Purlite are the same thing with different badges as far as I can tell, and I have a Purelite. Around $97 for a spare 4 hour battery is robbery. I now make my own 10 hour batteries for about $16 and 1 hrs work. (It's takes an hour cause I'm lazy).

Here's the parts list, all available from JAYCAR Electronics who have offices all over.
1800-022-888.

3 x AA rechargeable Nickel Metal Hydride cells with solder tabs. These have a capacity of 1650 mAH which is more than 3x the capacity of the 450 mAH cells supplied with the helmets. JAYCAR Stock No SB1702 @ $4.75 each.

1 x 2.5mm Power plug, JAYCAR Stock No PP-0510 @ $1.55.

Here are the connection details, written for non electrical woodworkers. Please excuse me if you have been electrified.

Wire the 3 cells in series, ie. cell #1 "+" terminal connects to cell #2 "-" terminal.
Cell #2 "+" connects to cell #3 "-" and so on.

Discard the plastic cover from the plug.
Connect the tag from the centre pin of the power plug to the free "+" terminal of the batteries.

Connect the terminal joined to the outer shell of the plug to the free "-" terminal.

I was able to tape the lot up so it looked just like the original pack and plugged into the helmet the same as the original.

You can use the charger supplied with the helmet but it will take 2 days to fully charge this larger capacity battery.

Otherwise make one to work off a car battery charger. This simple charger uses the principal that an incandescant globe draw a more or less constant current even with changing voltage so if you connect a 6 Watt 12V globe (car parking light globe) in the line from the RED "+" lead of the charger to the "+" lead of the battery pack, and connect the BLACK charger lead to the "-" on the battery you have a 5-7 hour charger for your new 10 hour battery.

The light will glow fairly brightly as the charge takes place.

soundman
17th June 2002, 11:13 PM
Any one who sells 3 x AA NiCad batteries and a plug for around $100 needs not to sell too many.
Most battery repackers would do the job with glee for half that price If you don't want to do it yourself. Try premier batteries if none else come to hand.
A 3 x AA pack is a pretty common configuration I wouldn't be surprised IF it could be found as a spare part for a phone or someting.
I a bit concerned about the charging circuit though. Much better circuits available as a kit. Duck back to jaycar & bend their ear, you will probably get more life out of your pack.
Cheers chaps


[This message has been edited by soundman (edited 17 June 2002).]

BrianR
18th June 2002, 08:54 AM
I confess that the charger I suggested looks somewhat agricultural, but it is actually very effective. It provides a 550 mA charge, the recommended 5 hour charge rate for these cells, while the unfiltered output from a battery charger gives pulse type charging which is superior to DC charging. I checked Jaycars chargers but they are intended for individual cells and are inappropriate for a pack. Electronics minded people will roll their own but for others this agricultural unit works damm well. http://ubb.ubeaut.com.au/ubb/smile.gif

[This message has been edited by BrianR (edited 18 June 2002).]

[This message has been edited by BrianR (edited 18 June 2002).]

soundman
18th June 2002, 10:27 PM
I have seen worse in "commercial" chargers.
Try 1 transformer, 1 diode, 1 resistor.
Not a constant current charger but i does charge the battery.
Heres a little known tip
Nickle cadnium batteries love the cold, best performance just below zero C.
To get more charge in your NiCad charge it in the fridge. It works.

JackoH
20th June 2002, 01:41 PM
Soundman. Does charging in the fridge help to charge nicad batteries that have developed a "memory" and only hold charge for a short time?
This question from one for whom electrics are a complete mystery. http://ubb.ubeaut.com.au/ubb/confused.gif
Regards John H.

[This message has been edited by John Hambly (edited 20 June 2002).]

Iain
20th June 2002, 02:32 PM
John, they need to be discharged completely then charged fully. By discharged completely I don't mean the device it is operating won't work any more as there is still probably still a charge.
I use a small light globe of a similar voltage and attach it to the battery until it is nearly out, low wattage preferably.
After that give it a full charge and a bit, if that doesn't work, buy new batteries.
Also, don't pull batteries out of the charger before they are fully charged as this will create a memory problem.
If you do decide to replace batteries, try to go for Nickel Hydride, they are about the same price as NiCad and are less prone to memory problems.
And, a slower charger is better for the battery than a fast charger, even if it is inconvenient.
What batteries are giving you problems anyway? I may be able to steer you to some locaL suppliers for aftermarket batteries if it is for a camera or similar.

BrianR
20th June 2002, 06:42 PM
Iain, As you say, the memory effect is reduced by cycling the batteries 2-3 times, but with the modern cells a fast charger is always better provided the cells don't overheat.

Iain
20th June 2002, 07:17 PM
Providing it is pulsed???

zathras
21st June 2002, 08:51 AM
Regarding draining nicads with a light bulb.

DON'T DO IT

That would be the surest way to kill an otherwise semi servicable battery pack.

Nicads are very prone to being damaged if a reverse polarity is put across them. Remember that a battery is in fact several Nicad CELLS in series.

What will happen is the weakest cell will end up fully drained, but the others will still have charge and manage to keep the light bulb lit. Keep on going and the weakest cell ends up with a reverse polarity across it - it's all downhill from there for that cell.

This is why you should ALWAYS stop using a cordless tool as soon as it shows signs of slowing due to a flat battery.

There is no problem discharging INDIVIDUAL cells to zilch, but there ain't many packs I've seen where you can gain access to each cell individually.
In fact the ideal way to store nicad CELLS is to physically short them out believe it or not!

Lead acid however must be fulled charged for storage.

Cheers Ray

Shane Watson
21st June 2002, 09:07 AM
Getting back to the original topic. "Dust Protection".

It often amazes me at some of the levels & expense hobbiest's go to in the aid of protecting themselfs and surroundings against dust. Yet when walking into a professional workshop its nothing to be walking on two foot of dust & shavings etc and the limit of persoanl protection is usually a cheap disposable dust mask (if they're worn at all!).

This is merely an observation than a statement or comment. I mean its kind of ironical that the people whos income & livlyhood rely on timber have little concern of the risks involved (that is a generalisation).

Cheers..!

soundman
21st June 2002, 10:54 PM
The slack attitude to dust generaly in the industry has given us a bad rep' with both regulators and insurers.
Many people instantly think of piles of dust associated with timber work. I have been in timber workshops where everything in sight high and low is covered in an inch of dust.
Think of the panic that would induce in a fire insurer particularly when the worker is a smoker. http://www.ubeaut.biz/traashcan.gif
I could not work that way and why should you.
I love my dust extractors and my vacume cleaner and my brooms.

How much does uncontrolled dust cost the people in spoiled work and sweeping when dust extractors are so cheap.

Hate dust die die die!!! http://www.ubeaut.biz/machinegun.gif

zathras
22nd June 2002, 09:52 AM
Originally posted by Shane Watson:
Getting back to the original topic. "Dust Protection".

It often amazes me at some of the levels & expense hobbiest's go to in the aid of protecting themselfs and surroundings against dust. Yet when walking into a professional workshop its nothing to be walking on two foot of dust & shavings etc and the limit of persoanl protection is usually a cheap disposable dust mask (if they're worn at all!).

This is merely an observation than a statement or comment. I mean its kind of ironical that the people whos income & livlyhood rely on timber have little concern of the risks involved (that is a generalisation).

Cheers..!

What's the point ?

You can't tell me that you don't find your nose stuffed up, you cough and splutter etc if you've had a session of woodwork without taking due care as to not breathing in the stuff ?

If a hobbiest feels he needs to protect his lungs then that is probably more sensible to encourage than implying "the professionals don't, so why should you.", observation, comment or otherwise.

And so what if the thread has deviated a bit, I'm sure more value is being added to the discussion simply by bringing in related topics. Tunnel vision doesn't help.

Shane Watson
22nd June 2002, 11:52 AM
zathras - mate you can jump down of that damn big horse of yours now! http://ubb.ubeaut.com.au/ubb/eek.gif

My point is that there was no point. Merely stricking up a bit more interest in the topic. If you dont agree with my observation you have the option not to comment, but to make insinuations? I never said I agree'd with my points either. But the fact remains, most professional outfits don't control there dust to the extent hobbiests do. You obviously feel strongly about the right to control dust. Well good for you - more power to you! I certainly agree with you on that point, but it might also help if you put them glasses back on & re-read exactly what I wrote. As you state 'Tunnel vision dosn't help.'

[This message has been edited by Shane Watson (edited 22 June 2002).]

Iain
22nd June 2002, 05:36 PM
Shane, I can give lessons on how to get off a horse..........quickly http://ubb.ubeaut.com.au/ubb/biggrin.gif
Zathras, sotto voce don't worry, we all get burnt occasionally.

------------------
: http://community.webshots.com/user/iain49

zathras
22nd June 2002, 09:21 PM
Shane,

I have read and read your post but it still seems too obtuse to me. That's the trouble with electronic messages, it is hard to tell if people are joking, serious or otherwise.

It now seems obvious you weren't implying what I said so I humbly apologise for backing my horse up and dumping a load of fertiliser in the forum :P

As for professional operations, this is just a hunch not having worked in such places, but if they're much like other industries I suspect people don't want to be seen as sissies wearing protection gear. Perhaps peer pressure is as much to blame ????

P.S. horse has been marched off to knackery. http://ubb.ubeaut.com.au/ubb/eek.gif

Cheers Ray

Iain
23rd June 2002, 09:09 AM
I have seen much of what you are saying, bloke with massive angle grinder cutting hole in wall, standing on top of step ladder, whoops. Never liked that arm much anyway, too lazy to go and get a scaffold.
Worker picks up small engine block because boss called him a woos for going for a trolley, permanent back injury.
Not wearing upper body protector and getting thrown off high horse, eight broken ribs and a broken wrist (copped some crap off the forum for that one last year).

JackoH
23rd June 2002, 11:11 AM
I knew a plasterer who was very good at his job, but not very dust concious. Retired at 50, dead at 60 with emphysema.(dust induced,there's a black joke in there somewhere!)
You often don't hear about the later effects of dusty occupations on tradesmen or,for that matter hobbyists.
More power to anybody who takes extreme precautions to protect themselves from this killer. Make no mistake,All timber dusts are potentially deadly,and will kill you sooner or later
Regards. John H. http://ubb.ubeaut.com.au/ubb/biggrin.gif:

soundman
24th June 2002, 10:34 PM
Back to the side issue of rechargable batteries.
Zathras mate you need to get your facts and battery types in order.
Most importantly

THE SUREST WAY TO KILL A NI CAD BATTERY IS TO SHORT THE TERMINALS AND STORE IT THAT WAY.
The only type of battery that should be shorted in storage is "Nickle Iron" a cell type you are unlikely to ever encounter.

Secondly
I have been using and servicing NiCad batteries for many years and can tell you for sure, deep discharge is a valid and safe method for restoring memory affected NiCad cells.

Just don't flatten them dead stone flat.

As for polarity reversal. unlikely in packaged battery packs particularly good quality ones which use batch matched cells. At least in their usable service life.


Ian
As for the pulse charging, there are some very sofisticated charging systems which use pulse charging, but it is unlikely that a poorly filtered charging supply qualifies as a pulse charging system.

Now how was that dust issue.

zathras
25th June 2002, 09:34 AM
Soundman, mate,

"Those in glass houses should not throw stones", especially when it comes to terminology.

If you re-read my post, I did not advocate SHORTING A BATTERY. I said CELL. There is a huge difference.

Shorting a BATTERY WILL destroy any BATTERY pack. You are possibly correct though in Nickel-Iron being stored shorted, but once again each CELL not the BATTERY. T'was a long time ago I was taught about batteries and I know it was some form of nickel battery that should have been shorted for storage.

However, if reverse polarity is not a real problem, why then do so many BATTERY packs end up buggered after a user has gone beyond the recommended end point by driving in that "one last screw" ?

The biggest problem with Nicads is that they do prefer to be stored discharged, If you do keep them on a charger you'll end up with dendrites shorting the CELLS.
This is where the pulse charger comes in for reconditioning, especially those that go thru charge/discharge cycles at a rapid rate, they can actually help remove denrites.

Nicads will also self discharge over time.

All in all they really are bastards of cells. When you really want them, they need to be fully charged, but storing them that way is not recommended, you should store them in a discharged state. You also should avoid fast charging as it is far too easy to overcharge them. They old 14hr charge is the safest way to recharge, from a drained pack.

So ideally you need to think 14 hours in advance that you'll be needing that battery pack so it is right to go for the job. And then leave the thing discharged until the next time.

That never works in practice, I too leave the cordless battery on the charger too long and sure enough over time the capacity drops off.

I also admit that in practice the only way to safely discharge a nicad BATTERY is to do so until a sudden drop in voltage occurs, which indicates one of the CELLS has reached their end point. This will mean there is still some charge in the battery. but discharging further puts at risk reversing the polarity of the dead CELL.

I agree that then the battery pack should then be recharged from that point.

In an ideal world, all the cells would be identical and the battery would become flat as all cells die simultaneously, but we live in a imperfect world as demonstrated time and time again in this forum http://ubb.ubeaut.com.au/ubb/biggrin.gif (including myself)

Cheers Ray

Sandy Johnston
25th June 2002, 10:48 AM
I have never had any problems with dust from my battery pacs.

Regards
Sandy across the ditch