Smokin'

[Guest]

I'm gagging on powder smoke. What do you all do to vent your ovens? My oven has no vent except the top of the door seal and sometimes the smoke overwhelms my shop. I always leave my powder booth exhaust fan on, which vents to the outside but it won't keep up. Anyone run an oven vent through the roof. It seems to me another exhaust fan won't do it because I'm sure I've got a negative pressure problem now but it's to cold 6 months of the year in Ohio to open a window.
I swear after a smokey evening of powder coating I have more dreams during sleep than when I don't coat. Sounds funny but that smoke is making me crazy.

[halfbaked]

Re: Smokin'

How much powder have you been smokin?
Do your dreams change with color change?
Might want to check you oven temp

[Guest]

Re: Smokin'

I dont really know what you mean, I dont have any smoke coming out of my oven when I cure, at all. I also dont have any vent system.

[mjwash]

Re: Smokin'

I dont really know what you mean, I dont have any smoke coming out of my oven when I cure, at all. I also dont have any vent system.

It's rare that I don't see smoke from the powder. It seems some are worse than others especially the satin/matte finish. Usually choke myself on large parts, frames and such. Small parts definitely have an odor but not enough powder to create the cloud.

[Guest]

Re: Smokin'

There must be something else burning, I have never had smoke from my oven from powder.

[rbroker]

Re: Smokin'

The only powder I've seen smoke are wrinkles. And it only smokes for a small time frame of the temp ramp up.

Crack your door a 1/2 inch and suck some the air out with a box fan.

But I agree, you got something else burning....hopefully not the garage.

[wiseguyz]

Re: Smokin'

I've got to disagree with you guys on this one. When the powder is curing, there is almost always some smoke. I've found the urethanes and wrinkles smoke a lot more than others, and it's especially noticeable on large parts. Usually when I'm done curing, I open my shop door for a minute, and sometimes it looks like the building is on fire! I don't have any ventillation to the outside, but I plan on installing a cross-draw fan & louver just to take care of the situation without having to open the door.

[Brune292]

Re: Smokin'

I rarely see any smoke and the only vents on my oven are around the doors where they dont seal very good. Have you cleaned the inside oven walls? Insulation smoking? I agree powders to let off a little smoke, but shouldnt be near enough to smoke out your shop.....I would be checking other stuff. Just my .02

[mjwash]

Re: Smokin'

I rarely see any smoke and the only vents on my oven are around the doors where they dont seal very good. Have you cleaned the inside oven walls? Insulation smoking? I agree powders to let off a little smoke, but shouldnt be near enough to smoke out your shop.....I would be checking other stuff. Just my .02

Definitely powder smoke. When I check temps with the IR I can see the parts smoking off. There is no smoke unless I'm curing parts. Oven is very clean and insulated with mineral wool. Wise is right about the wrinkles they will run me out of the shop, I often have to open the overhead door to ventilate. I'll call tech support and get their take on powder smoke.

[Guest]

Re: Smokin'

Every oven must be exhausted. Exhausts create a negative environment so that air seals operate properly and remove VOCs and other cure products from the oven. Additionally, the exhaust purges the oven prior to start-up. The requirement for purge is to change the enclosure atmosphere four times in approximately 20 min prior to ignition.
The main job of the exhaust is to maintain a safe environment. A good rule of thumb is to exhaust 10,000 cu ft of air (expanded for elevated temperatures) for every gal of solvent driven off in the oven. This assures the oven atmosphere will be maintained below the lower explosion limit of the solvent with a safety factor of four.
Exhaust also eliminates smoke build-up. Smoke is produced when curing some electrocoatings and powders. The exhaust requirement here is best recommended by the coating supplier.

[wiseguyz]

Re: Smokin'

Every oven must be exhausted. Exhausts create a negative environment so that air seals operate properly and remove VOCs and other cure products from the oven. Additionally, the exhaust purges the oven prior to start-up. The requirement for purge is to change the enclosure atmosphere four times in approximately 20 min prior to ignition. This applies to gas-fired ovens
The main job of the exhaust is to maintain a safe environment. A good rule of thumb is to exhaust 10,000 cu ft of air (expanded for elevated temperatures) for every gal of solvent driven off in the oven. This assures the oven atmosphere will be maintained below the lower explosion limit of the solvent with a safety factor of four. Powders don't give off solvents...they smoke
Exhaust also eliminates smoke build-up. Smoke is produced when curing some electrocoatings and powders. The exhaust requirement here is best recommended by the coating supplier.

Thanks, KING.

[Guest]

Re: Smokin'

and you guys thought I was just a dumb blonde

[mjwash]

Re: Smokin'

Every oven must be exhausted. Exhausts create a negative environment so that air seals operate properly and remove VOCs and other cure products from the oven. Additionally, the exhaust purges the oven prior to start-up. The requirement for purge is to change the enclosure atmosphere four times in approximately 20 min prior to ignition.
The main job of the exhaust is to maintain a safe environment. A good rule of thumb is to exhaust 10,000 cu ft of air (expanded for elevated temperatures) for every gal of solvent driven off in the oven. This assures the oven atmosphere will be maintained below the lower explosion limit of the solvent with a safety factor of four.
Exhaust also eliminates smoke build-up. Smoke is produced when curing some electrocoatings and powders. The exhaust requirement here is best recommended by the coating supplier.

It sounds like I need an exhaust, thanks for the info. Could you tell me how to properly exhaust my oven? Preferably one that vents out of the shop. My oven is 4'x4'x6' and about 43KW of electric heat.

[wiseguyz]

Re: Smokin'

For an electric oven like yours (mine is nearly identical to yours), a simple 1" pipe through the side near the top should suffice to keep pressure from building and to let smoke out. Like I said, I plan on putting a through-wall fan with a louver on the opposite end of the building so I can draw fresh air through when the exhaust fan is running, sort of like an exhaust hood. The air exchange thing is good in theory, but any time you have air sucking into the oven, dust and crud can be sucked inside as well. Thats why I prefer to have mine unvented (against other recommendations).