Minimal requirements to safely spray em6000

[John Coloccia]

Anyone know what the absolute minimum I need to safely spray the Target coatings is? Obviously a mask to prevent breathing any wet over spray. Would it be sufficient to grab a box fan, for example, stick a filter on it, and spray? I'm talking about not venting outside at all. I really would like to understand what the absolute minimum is. If I do that, how long until I could remove the mask after I'm done spraying?

Again, I'm not talking about best practices. I'm talking about what the absolute minimum is in order to safely spray this stuff indoors.

Thanks for any insight.

[Jamie Buxton]

The EM6000 that doesn't land on the workpiece mostly dries in the air. That is, the overspray is really dust, not fluid. That said, I don't like to breathe the dust. I wear a good respirator, and open the shop doors to get good air flow through the shop. If I don't open the doors, the dust can hang in the air for quite a while -- tens of minutes. Perhaps one of those air cleaner things would help, but I've never tried one. An alternative is to just live with the dust: spray a coat, step out of the shop until the coat dries, come back to spray the next coat, etc. When you have all the coats on the piece, quit for the night. The dust eventually has to settle out.

[Harvey Pascoe]

John, I think you are mistaken about the mist drying. Very fine particles of mist, much like water vapor, tend NOT to dry in the air but only after they come in contact with something. I do all my spraying outside and the surface of my vehicle can attest to this statement. Its far enough away that I thought the mist would be dry before it contacted the car but I was wrong.

Why don't you spray it outside and then promptly bring it inside? That is what I do on cold winter days. The workpiece is still warm by the time I bring it back in.

As for vapors, these WB finishes contain gylcols which can cause brain damage in rather small amounts. I know, I found out the hard way, having heard wrongly that that they were not harmful. I experienced temporary blindness in one eye and severe dizzy spells. And this after spraying outside and using the wind to carry vapors away from me. Make sure you do not breathe the vapors even in the smallest amounts. The worst of it is YOU CAN'T SMELL IT.

[John Coloccia]

The glycol ethers were my concern as well. I'm trying to get a feel for exactly what I can get away with. The current plan is to simply set up a box fan, open the doors, and spray. The MSDS requires "mechanical exhaust" but no "local" exhaust, which is a fancy way of saying that you don't need a fan to exhaust at the source, but you do need ventilation beyond just natural air currents and dispersion.

I plan to install an actual booth setup for solvents, but I'm simply running out of time. If I try to to do this now, I'm going to be fighting the weather the entire time so WB through the winter at least.

Spraying outside is very inconvenient from a fixturing standpoint. Also, I do some finishes that require spraying for rather long periods of time....sunburst finishes come to mind. There's a lot of light mist coats going on, looking closely under excellent lighting, etc. It's just not practical to do it outside as a general plan.

[Daniel Berlin]

The glycol ethers were my concern as well. I'm trying to get a feel for exactly what I can get away with. The current plan is to simply set up a box fan, open the doors, and spray. The MSDS requires "mechanical exhaust" but no "local" exhaust, which is a fancy way of saying that you don't need a fan to exhaust at the source, but you do need ventilation beyond just natural air currents and dispersion.

I plan to install an actual booth setup for solvents, but I'm simply running out of time. If I try to to do this now, I'm going to be fighting the weather the entire time so WB through the winter at least.

Spraying outside is very inconvenient from a fixturing standpoint. Also, I do some finishes that require spraying for rather long periods of time....sunburst finishes come to mind. There's a lot of light mist coats going on, looking closely under excellent lighting, etc. It's just not practical to do it outside as a general plan.

zipwall + exhaust fan in the garage is what i use for this purpose.

Basically, I build two walls with plastic sheeting to form a tunnel in the center of the room, cover the floor, open the door to the house (to get more airflow), put a cheap box fan on the "intake" side of the house, and an exhaust fan on the "output" side of the little plastic sheeting tunnel. The sheeting has *maybe* 1/16" of an inch opening at the top and the bototm.
I can spray with wild abandon in the middle, without it getting cold (well, "as cold"), without it getting on anything, and i can still fixture what i need to from the ceiling or whatever. Works great. In my case, I calculated the area inside my tunnel and sized the floor fan i bought for exhaust appropriately.

All told, this setup cost me about 200 bucks, and compared to spraying stuff outside or at the very edge of the garage all the time, works great.
If all you care about is the vapors, and you are worried it still might get too cold, you could even keep the door closed until you are finished, then take down the zip poles (assuming they are in the way), open the door, and exhaust the hell out of the garage.

[Jim Becker]

I use a quality cartridge filter mask and use my air filter to help get any suspended particles out of the air. Outside of that, if you would use house paint, you're good to go with this stuff. That's one reason why I use it...

[John W Henderson]

I work at a large company that makes respirators. When people say "quality" or "good" or "cartridge"... that's got to translate to something. The ratings are what you should be thinking about. N95 is your standard particulate respirator. HERE is a list of various specs. You shouldn't need any oil resistance in this case. Whether you go N95 or N99 is up to you.

The "cartridge" type is often called a bayonet filter. Push + twist inserted cartridges in a non-disposable mask. I use these as well. What you're looking for there are VOC filters -- volatile organic compound filtration cartridges. Sometimes just called organic vapor filters. These usually have activated charcoal inside as well as a fibrous filter material. Think Brita filter on your face.

You may know all this stuff -- just thought I'd add it. If you've got stuff wet or dry in the air that used to contain some type of volatile (prone to evaporation) hydrocarbon... you should be using a VOC filter. If you have dubious air exchange rates, even if it is drying in the air... that "drying" means it's releasing the solvent in the air.

Hope that makes sense!

[John Coloccia]

Yay, hooray....ordered my spray booth fan. Have a design that should work fine for EM6000 and light shellac tinting.

John: yes, I'm very careful about my masks and in fact may just upgrade to a positive pressure fresh air respirator like the Hobby Air. A hood would work much better for me than a mask as I'm normally sporting some sort of beard or fuzz. I went through all of that hand wringing when I started shooting epoxy primer for my airplane building adventure.

[Harvey Pascoe]

I guess there are a lot of ways to do this. Being in Florida, I can have my "booth" or rather spray area outside up against the side of the house where I got those wire rack type closet shelves laid across saw horses (to eliminate spray blow back).Plus if spraying against a solid surface you get dirt that you don't see that gets lifted by the air pressure, even if you blow it off first, always some remains. So the wire racks work well for this.

I chose a location where the wind is either blowing right to left or vice versa so I have natural air movement as my fan. When there is no air movement I will wear the respirator but I wear glasses and that's a real battle just trying to see what I'm doing. The real down side to this arrangement is the rare times there is too much wind like yesterday when spraying was out of the question, more because of the blizzard of dust and debris flying out of the trees.

[John Coloccia]

Well, I decided that I wanted to be able to spray tinted shellac also as that's just how I'm accustomed to spraying colors so I'm actually building a little booth with a real spray booth fan. Speaking with the manufacturer we determined that a 2000cfm fan would do me and that for the truly tiny amounts of shellac I'm spraying (maybe 1oz at a time) that I can just take some 12" flex tubing, and toss it out the shop door for exhaust. It's a pretty reasonable solution that will keep me up and running safely, year round. I'm not sure I'd want to do lacquer like this, but honestly I really don't ever want to spray lacquer again, so no big loss here.

[Jerome Hanby]

Can you tint the shellac enough to get some very pronounced colors? I'm thinking of use on toys to get bright reds or blues.

[John Coloccia]

Can you tint the shellac enough to get some very pronounced colors? I'm thinking of use on toys to get bright reds or blues.

Uh huh....

photo.jpg

I recommend you use Transtint dyes. The key, as with all things shellac, is very light coats. I do the entire sunburst in one session, normally. I start spraying light coats, and then I use just the air from the gun to force the shellac to flash off quickly. Then I spray some more. I think this particular burst took me maybe 5 minutes or so. You can also spray slightly heavier coats and give maybe an hour between coats, but to get the shading I want I'm using a Devilbiss touch up gun set to spray a very fine mist....it's very dry when it hits the guitar and it's very fine. The texture ends up being slightly rough but the next coat of clear shellac (my "sealer" coat for the colors) flows it right out into glass.

To do the burst, I usually spray Transtint dissolved in alcohol for the yellow in the middle....right on the bare wood. Then I do a light coat of 1lb cut shellac to seal it in. Then I go on top with the color. Then I seal with another light coat of 1lb cut. For a solid color, I would do one seal coat of 1lb cut and then follow up with color. I always like putting down a seal coat before coloring to prevent blotching the wood. I don't bother with the amber tint in the middle because it's very light, doesn't blotch very much, and what little blotching I get actually makes the piece look a bit more organic.

edit: BTW, you COULD do the whole piece amber and then burst on top of that, but I like my way better. The red over amber looks different than red over bare wood and I get almost a three tone finish as it goes from amber, to a warm orange, to a deeper red at the edges...almost like a sunset.

[Jerome Hanby]

That's beautiful! I would never have suspected that you were using shellac for that. Totally answers my question!