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Parm
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I will never discourage anyone taking steps to protect health, but look at how much work your planning to do, how often and then for how long.
If your a low level user, leave the door open for general ventilation. AND use a powered filtering welding shield. It will always go where you are. The extraction system your looking at probably won’t.
The proper way of doing what you want will be a Nederman type arm. I think @skotl has one in his workshop. These things are self supporting and quite expensive, require a decent amount of headroom etc.
Cost up your DIY ventilation arrangements, budget how much time you need to install then factor in the amount of faffing around that might be required to get it working. Compare this to the cost of a powered filtering visor
Detached garage.
Wouldn't mind an airfed mask, much more costly though I think. Have used a Universal branded one recently which worked okay, tempted by one Esab make where the air comes in through the side or bottom of the helmet rather than the top.
The_Yellow_Ardvark
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Think simple PPE.
Then as your set up grows then you can invest more.
Then as your set up grows then you can invest more.
Shedendman
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I just love the smell of old underseal,oil,rust,paint 1st thing in the morning,mmmmmmmmmmmmmmmm
Parm
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Double check that, air coming in from the bottom sounds wrong to me for a welding visor. It’s likely to create an eddy and potentially draw in dirty air from outside.
Welding visors and similar always provide air from the top, thus giving clean air across the breathing zone and pushing away dirty air at the bottom on its way out
Won't be buying anything until into new year now; so I have time to weigh up the costs I suppose.
Given the stuff I've found on Amazon this evening, I think I could get a working system for £70-100 if everything works. Believe I have access to all of the tools I would need, and time isn't a problem right now.
On the other hand, especially if there are some good sales on in January what I would spend might end up being 25-30% towards an air fed helmet, are they called PAPR units? and as I'm not liking my current welding helmet either, that could be a much better investment as you guys point out.
Given the stuff I've found on Amazon this evening, I think I could get a working system for £70-100 if everything works. Believe I have access to all of the tools I would need, and time isn't a problem right now.
On the other hand, especially if there are some good sales on in January what I would spend might end up being 25-30% towards an air fed helmet, are they called PAPR units? and as I'm not liking my current welding helmet either, that could be a much better investment as you guys point out.
Parm
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I just love the smell of old underseal,oil,rust,paint 1st thing in the morning,mmmmmmmmmmmmmmmm
I like the smell of ethyl acetate
I'll try and find the model to show you. I believe the idea was to stop the air from drying out the eyes, which is why it stood out to me as I already have dry eyes, and noticed needing to use eye drops more when I used the Universal airfed helmet a couple of weeks back.
Shedendman
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£70-£100 what,on all the ducting to?
skotl
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Think there was a nederman arm on sale here a while back at what I thought was a very good price.
Can't find the airfed helmet where I think it said the air comes in through the bottom, the pipe connects at the top like others but is routed internally so it enters the helmet from the bottom. I think it was an ESAB model, but I can't find it now.
Have found both a GYS and ESAB air fed helmet I would consider in the £450-700 price bracket. The Esab Sentinal complete unit at around £622 over on Engweld seems good on paper, though I'd feel better trying one before spending so much. Engwell have a shop I believe in Bradford which isn't too far from me; if they let you try things out of course.
EDIT: The helmet I was thinking of earlier turns out to be the Esab Sentinal A50 Air, just watched a promo video of it and they mention it.
https://engweld.co.uk/product/esab-sentinel-for-air-complete-unit
Have found both a GYS and ESAB air fed helmet I would consider in the £450-700 price bracket. The Esab Sentinal complete unit at around £622 over on Engweld seems good on paper, though I'd feel better trying one before spending so much. Engwell have a shop I believe in Bradford which isn't too far from me; if they let you try things out of course.
EDIT: The helmet I was thinking of earlier turns out to be the Esab Sentinal A50 Air, just watched a promo video of it and they mention it.
https://engweld.co.uk/product/esab-sentinel-for-air-complete-unit
Have a look at COSHH ventilation requirements too. Applicable to industry rather than "domestic" but gives a very good indication of what's required. I went the full nederman arm route, second hand, including fan for less than 300 quid. No debate at that price then, to be fair you could dick around forever trying to get something cheaper, or try lashing something together, but it wont work as well. If you look around you can find old systems cheap enough. As skotl said there was one on here recently. Never figured out why it wasn't snapped up.
mtt.tr
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Ali
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It might be worth considering a cheap hot wire anemometer, or borrowing a good one - perhaps someone at college can help you out.
Weld fume is not my area, but like most extraction the problem is that expectations of how well it works outweigh actual performance. A bit like this:
The fume needs to be captured at a velocity of 0.5-1m/s. At half a duct diameter away you’re down to 30% of whatever the measurement is at the face of your ‘hood’. At one diameter away you’re at 7.5%.
Probably from the same book as Parm
I won’t go into measuring this and calculating an effective range, but suffice to say just having the hood in the vicinity of you’re working area isn’t going to do anything much, and it all comes back to the fan spec and ducting design.
Edit: I hate typing on my phone
Weld fume is not my area, but like most extraction the problem is that expectations of how well it works outweigh actual performance. A bit like this:
The fume needs to be captured at a velocity of 0.5-1m/s. At half a duct diameter away you’re down to 30% of whatever the measurement is at the face of your ‘hood’. At one diameter away you’re at 7.5%.
Probably from the same book as Parm
I won’t go into measuring this and calculating an effective range, but suffice to say just having the hood in the vicinity of you’re working area isn’t going to do anything much, and it all comes back to the fan spec and ducting design.
Edit: I hate typing on my phone
Parm
Respect The Sound System
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You sad sad person !!!
Parm
Respect The Sound System
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Matt, just for you.
This is where it’s at. The bible of fan engineering. It’s very old but still a go to source
Thank you very much; interesting that the cfm goes down simply by adding a cone to the end of the duct. I like the welding bench system where they use a "plenum" to suck in the fumes to the back rather than straight up.
All seems much harder to get right than I imagined, can see why people prefer airfed helmets, but very interesting reading.
