Finishing fumes

[gravelybob]

In the winter I'd like to expel the fumes in the shop when I'm finishing projects but still keep the heat in. Normal ventilation doesn't allow this. Any ideas?
Thanks, Bob

[sacherjj]

I have seen setups with air heat exchangers. This was on Ask This Old House or similar type of show. They installed them down in the furnace area. The idea was to bring in a certain amount of fresh air, but try to exchange as much heat as possible between the air going out and the air coming in. Although I doubt they are talking enough volume to really do what you want with much efficiency. I am looking at water based finishes for my garage work during the winter. I am further compounded by sharing a gas water heater and gas furnace that does not allow any type of flammable fumes.

Did a quick search. It is more expensive than I expected, but this type of thing is what they installed.

High speed: 150 CFM; typical*: 120 CFM; low speed: 90 CFM
Heat Recovery Efficiency: High speed: 63.5%; typical*: 72.5%; low speed: 79.1%

You would probably want to keep the finishing area really small. Looks like it moves a decent amount of air and keeps some type of efficiency. You are still going to require a pretty strong heating system to go along with it. Makes me wonder if some type of heated heat exchanger is a better idea. Have a heater heating the air coming in, after it has gone past the air going out. The efficiency wouldn't be as good, but $500+ can buy a really nice heater.

[Thom2]

These are pretty pricey, but that's a common thing when you're talking about safety equipment for finishing. I have no experience using them, but it's something I've been looking at trying some time, you'll probably beat me to it so let me know how they work

http://www.jdstools.com/browseproduc...Optional).html

[steve-norrell]

From a newbie . . . in Alaska.

I am not sure that a heat exchanger would save enough heat to make it worth it and I doubt that a charcoal filter would do the job fast enough to make it an environmentally safe work area.

This is what works for us but we have an attached garage. I use two exhaust fans, one is controlled by a motion detector switch; the other is manual controlled and is used as needed. The fans and the weather stripping on the outside doors (including the one for the cars) is tight enough so that air is drawn from the house when the fans are on. Admittedly, this does draw heat out of the house, but we haven't found it to be a problem. In any case, it is certainly far better than no fan at all.

In any case, the cost of replacing the heat is small indeed, compared to the long term cost of breathing the fumes.

[Greg in Maryland]

I am beginning to get around to finishing my workbench, so this discussion is timely.

Regarding fumes, is the concern that the fumes will travel throughout the house or is the concern for the user (me) at time of application? I have a good respirator so I am not worried about myself during application. I work in the unfinished basement with no air inlets in the room, though the furnace is in the room. However, I presume that there are air inlets in the finished part of the basement (I am upstairs and too lazy to go downstairs to check). Will the fumes easily travel throughout the house?

Also, how about the flammability potential of these chemicals? My gas water heater is in the room and I wonder about the risk of combustion if fumes travel to the gas water heater.

Any thoughts would be appreciated.

Greg

[Slik Geek]

Fumes in the house

Greg,

I just completed finishing my workbench base during cold weather (so the house was sealed up). I used Antique Oil. My bench base is rather beefy, so there was a decent amount of surface area. (Much more area than I usually am finishing).

I discovered that the fumes primarily went straight up through the house into the highest living space. I worked in the basement, and a short time later went to bed on the 2nd floor. Guess which room is directly above the workshop?

The fumes were far worse in my bedroom than anywhere else on the first and second floors. It seemed like the volatile solvent fumes went directly upward into my bedroom.

Needless to say, LOL was not pleased. We suffered the whole night with stinky solvent fumes - I'm sure that we didn't meet OSHA requirements for air quality in our bedroom!

When it came time for the 2nd coat of finish, my wife was understandably not happy. So I modified my approach.

I started much earlier in the day. I opened a window in the basement for ventilation during finishing, and left it open for a half hour or so after I was done. This helped considerably. There were no complaints from my better half that night.

You need some fresh air for ventilation! (At least during the peak solvent evaporation phase!)

Regarding the flammability potential, I don't have an expert opinion here. Apparently my solvent fumes were lighter than air, as evidenced by the concentration two floors above. The appeared to go straight up.

[SARGE..g-47]

I think basically everyone shares this problem in some fashion, just in different degrees depending on your individual circumstances... unless your shop is detached where a different set of ground rules come into play.

My shop is the 2 car, drive-under garage directly underneath the kitchen and family area that will never see a vehicle again. I've sealed the sheet-rock on top of the poured concrete foundation that steps down from the 1/2 basement behind the shop and under the bedroom area to avoid fume leakage traveling up.

And of course I wear a mask. In the summer, I just open the main doors and set up 24" fans in the rear of the shop blowing out. In winter (which is mild here in Atlanta for the most part compared to more nothern locations), I always raise the room temperature before starting the finish. I have tapped into the 1/2" natural gas pipe line that runs in the ceiling of my shop to the gas fire place starter. Installed a 45,000 BTU space heater that heats the shop very quickly as it isn't often we get under 30 degrees even at night.

I try to always finish in the daytime when temperatures are the most modest. When time to start, I just slide a 12" wood block under the forward doors after slightly raising them. Fans are again pointing toward out-side. When finished, I will lower the doors to about 4" but leave the fans blowing outward. I vacate the shop and wait for the finish to dry and cure.

I can go upstairs with plenty to do or I can go into the rear basement which serves as a wood-rack room and assembly area. Just plan my work so there is no down time. The central air unit is there and with 12' poured concrete walls the temperature is warm in winter and cool in summer. No dust allowed in that back area with the exception of hand-plane shavings and sharpening grit as I sharpen on a second work-bench back there. I have two temporary assembly tables there and a low-boy assembly table. Glueing is allowed there after confirming years ago that no major amount travels up-stairs through the central AC-heat unit. With my wifes keen sense of smell.. I would have head about it. ha.. ha...

I think everyone has to just analyze their own situation and take action from there. We all have something in common, but we all have widely varying circumstances that we have to confront head-on and sometimes navigate around!

Regards...

[Greg in Maryland]

Sarge and Slik Geek

Thanks for your replies. I think I'll wait for spring weather (next week, maybe) and do the finishing in the garage or outside. LOML would not be amused to smell fumes throughout the house.

Happy Holidays!

Greg

[steve-norrell]

Sarge and Slik Geek

Thanks for your replies. I think I'll wait for spring weather (next week, maybe) and do the finishing in the garage or outside. LOML would not be amused to smell fumes throughout the house.

Happy Holidays!

Greg

Spring weather next week? How about maybe in April or May? Must be nice.

My strategy was to create a negative pressure in the work area that would draw warm air from the house through any openings or when a door was opened. As noted above, I use a motion detector switch on one exhaust fan to protect against "senior moments" and a manually-controlled second exhaust fan to use as needed. The motion-activated fan stays on about 15 minutes after I leave the garage. Both fans are through-the-wall installations, avoiding the complications of duct work in the area over the garage.

The garage is heated but by drawing air from the house, I get warmed air so the garage is maintained at a reasonable working temperature. Also, the draw on the house is not so severe that any problems related to house heating have appeared. Also, the inside air from the house is relatively clean, unlike the relatively dusty air that is prevalent here.

But, as noted elsewhere in the thread, the solutions have to be individually tailored and twenty different respondants are likely to offer 25 or more different solutions, all of which work in at least one shop.

Now, as to getting spring weather next week . . . .

Regards, SN

[gravelybob]

In the winter I'd like to expel the fumes in the shop when I'm finishing projects but still keep the heat in. Normal ventilation doesn't allow this. Any ideas?
Thanks, Bob

Thanks for the replys. I live in southern Ohio and winters can be too cold to leave the shop open for any length of time. I work in a standalone 2 story 22x28 barn working on the 1st floor and NO spray finishing. I guess I'll just have to lose heat when finishing and let a decent amount of fresh air in at those times.