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| Fume Hoods http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=32397 |
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| Author: | Pat Hawley [ Wed Jun 01, 2011 9:37 am ] |
| Post subject: | Fume Hoods |
CA glue fumes give me flu-like symptons and I'm finding the UV cure finish fumes give me a head-ache. With the finish I'm not sure if it's something from the finish (can this be when there are supposed to be no VOCs?) or the ozone produced by the light. So I've decided to build myself a fume hood. Has anyone made one of these that can offer any tips before I start? I've got a cheap range hood that sucks 180 cfm that I basically intent to mount on an enclosure and vent to the outside of my house. Do you think this will work and any ideas of how big of an access opening I can have yet still have it effectively contain all the fumes? I'm also thinking of having it double as a dust free space by first running it with something like a furnace filter over the access opening. I'm hoping that will reduce the nib count when finishing. Thanks, Pat |
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| Author: | Corky Long [ Wed Jun 01, 2011 10:04 am ] |
| Post subject: | Re: Fume Hoods |
Cool idea. Sounds like a cost effective way to improve the air quality in the shop. Maybe I'm stating the obvious, but I'd still use a mask for spraying finishes, and using any other chemicals with fumes. |
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| Author: | WaddyThomson [ Wed Jun 01, 2011 10:07 am ] |
| Post subject: | Re: Fume Hoods |
You might want to consider what it'll do to your humidity control too. |
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| Author: | Laurent Brondel [ Wed Jun 01, 2011 11:47 am ] |
| Post subject: | Re: Fume Hoods |
Not to state the obvious too soon, but how about slowly phasing out CA use and UV cured finishes? Is it MEK that gives you headaches? That stuff is awful… Plenty of valid alternatives out there. Remember that allergies are cumulative: it's not going to get better with time, hood or no hood. |
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| Author: | Michael Smith [ Wed Jun 01, 2011 11:58 am ] |
| Post subject: | Re: Fume Hoods |
what about using a range hood. some have multispeed fans. |
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| Author: | Chris Pile [ Wed Jun 01, 2011 12:27 pm ] |
| Post subject: | Re: Fume Hoods |
If I did any finishing with CA I would do it in my spray booth with the fan turned on. It moved something like 1200 CFM, so the fumes disappeared instantly. For small jobs in the shop, I just turn on the fan to spread them around. Wearing a filtered mask helps your breathing, but your eyes may still water. If I was going to do it these days, I'd go outside! |
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| Author: | Kent Chasson [ Wed Jun 01, 2011 12:34 pm ] |
| Post subject: | Re: Fume Hoods |
It's tough to do well. First, if you are exhausting outside, you need an equal amount of intake air or the back pressure will drastically cut the fan's efficiency. Putting an intake vent close to the exhaust also helps keep you from sucking outside air into the rest of your shop and having heat/humidity problems. In order to get most of the fumes, you have to configure everything so there is not a lot of turbulence and the intake air is going past your work. I have found that, believe it or not, the capillaries in your eyes can absorb enough CA fumes to cause a systemic reaction. Chemical goggles help that. Like Laurent said, the best thing is to avoid it and that's what I try to do. For the few times I still use it, I use a respirator, goggles, and the hood. |
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| Author: | Howard Klepper [ Wed Jun 01, 2011 12:53 pm ] |
| Post subject: | Re: Fume Hoods |
Range hoods are not sparkproof. They don't have anything like the volume and fpm of a spray booth fan. Wear an organic vapor mask with Ca glue, and don't use cat finishes unless you have a good spray booth (with a good mask, too). |
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| Author: | matt jacobs [ Wed Jun 01, 2011 3:30 pm ] |
| Post subject: | Re: Fume Hoods |
Have you tried using odorless CA? They are more expensive, and don't come in as many different viscosities, but no fumes and odor. |
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| Author: | Pat Hawley [ Wed Jun 01, 2011 8:43 pm ] |
| Post subject: | Re: Fume Hoods |
Thanks for the replies. I use CA glue for rosettes and bindings. I find its advantages too compelling to give up on it easily. I have used odorless CA in the past and I guess I should look in to it for the future. The UV finish I am using is from CureUV. Its a one part finish. The folks at CureUV are adamant that there is nothing dangerous either explosion or health wise in the way of fumes coming from their product. They said if I am getting a headache, it must be from the light somehow but I don't agree. I'm definitely smelling something - and I'm brushing, not spraying on the finish. Never-the-less, I'm also a long way of giving up on this finish. The instant cure and the scratch resistance are tough to beat. I did some more poking around in the internet on fume hoods and found a rule of thumb that suggested a maximum opening for a fume hood with 200 cfm suction would be two square feet. That's close enough for my purposes. The point made about humidity control in my shop is a good one. Fortunately, the amount of time that I would need to be venting to the outside to get rid of fumes would be relatively short, so I think I'm OK in that regard. If I were using the enclosure just to try and create a dust free space, I could vent inside the shop. Part of the motivation for this is that CureUV people told me that PRS guitars, who use their system, go right from spraying to two step buffing, i.e. no sanding. Boy that would be nice. I'm guessing that a dust free environment is part of the equation to be able to create a nib free finish so I'd like to do some experimenting to see if I have any hope of doing that. I'll keep you all posted on how it goes. Pat |
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| Author: | Howard Klepper [ Thu Jun 02, 2011 1:26 am ] |
| Post subject: | Re: Fume Hoods |
Are you using the 100% solids stuff? I have trouble seeing how you can get a thin finish without some kind of reducer. Does it keep flowing out indefinitely until you put the light on it? |
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| Author: | Pat Hawley [ Thu Jun 02, 2011 6:12 am ] |
| Post subject: | Re: Fume Hoods |
Howard, Yes, and yes. It seems to be just as thin as the KTM 9 I used to use before I started French polishing. Pat |
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| Author: | turmite [ Sun Jun 05, 2011 9:32 pm ] |
| Post subject: | Re: Fume Hoods |
Pat have you experienced fisheyes in the solids? If so, how did you address them? I have a full set up that I have not even started testing yet, but talked with another user from this forum that had the fish eye problems. Mike |
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| Author: | Pat Hawley [ Mon Jun 06, 2011 3:40 pm ] |
| Post subject: | Re: Fume Hoods |
I wouldn't describe what I get as "fish eye" as much as nubs or nibs. There seems to be lots of these with the first top coat and fewer with subsequent coats. On the subsequent coats, many of them disappear as the finish levels. At most, I can manage to get 3 - 4 square inches of surface nib free. My first round of sanding, for which I use 400 grit dry, is to level and get rid of the nibs. Not really sure what causes the nibs but I figure if I can get a few square inches nib free, it must be possible to get a whole guitar nib free. I just don't know how. Pat |
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| Author: | woody b [ Mon Jun 06, 2011 7:43 pm ] |
| Post subject: | Re: Fume Hoods |
Quote: there is nothing dangerous either explosion or health wise Read the MSDS. I'll guarantee you the finish contains vinyl benzene. You don't need to be breathing that stuff. UV rays, especially the intensity required for curing a finish are dangerous too. Ironically, there's a company making UV cured polyester now that cures in normal sunlight. It does require 1% MEKP, in addition to the photoinitiator. For dust control, as well as safety, I'd recommend a spray booth with good ventilation, as well as good respirator. A hooded respirator that uses outside air is best. A tyvec suit will help with dust problems too and certainly can't be bad healthwise. Howard Klepper wrote: Are you using the 100% solids stuff? I have trouble seeing how you can get a thin finish without some kind of reducer. Does it keep flowing out indefinitely until you put the light on it? I'm glad I'm not the only one who's confused about the "100% solids" thing. |
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| Author: | mikemcnerney [ Tue Jun 07, 2011 5:18 am ] |
| Post subject: | Re: Fume Hoods |
Pat, I have several barn fans that I use with a rheostat for evacuating air. Busy bee has them. A 8" or 10" I have one on a piece of plywood mounted snug in the window frame. Then open another window a bit at the far end of the basement. I believe the cure UV varnish is made by greenlight coatings which I spoke with after I saw you. They may have a better tech support? Some of their products are water base & I suspect that's why you had some rust in one of your cans. Maybe filtering & storing in a plastic container would help. Those knibs are part of the issue, what and why are they? I think you said you tried leveling with the torch but I would be inclined to try that again or leaving the finish conatiner in a hot water bath? Heck I don't know, I'm just making stuff up. Mike McNerney |
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| Author: | Fleck [ Sat Jun 11, 2011 12:29 am ] |
| Post subject: | Re: Fume Hoods |
http://www.facebook.com/photo.php?fbid=2143142259577&set=a.2143142099573.130552.1276843701&type=1&theaterhttp://www.facebook.com/photo.php?fbid=2143142419581&set=a.2143142099573.130552.1276843701&type=1&theater Here is my Jet air filter that I removed all filters and ducted out the back of my shop. I have it on whenever dust is being created or after spraying during off gassing. Its setup in our bathroom so we open the door set the timer and let it run. |
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| Author: | treadwm [ Sun Jun 26, 2011 4:23 pm ] |
| Post subject: | Re: Fume Hoods |
Quote: Ironically, there's a company making UV cured polyester now that cures in normal sunlight. It does require 1% MEKP, in addition to the photo initiator. What company is that? Sounds like an interesting product. |
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