[CAS14]

As you know, varnish should be applied where toxic and flammable vapors won't accumulate, and where temperature is moderate and humidity is not too high.

My initial thought was to insulate the garage and heat it with a space heater when applying varnish and while it cures. However a few measurements in the attic, and some consideration of an uninsulated wall made it apparent that the cost of this approach might deplete my beer fund.

Finally, the light went on, the solution had been there all along. I already have a little paint/varnish booth in the garage, and all it needs is a little heat. Here in Oklahoma, it is prudent to have a tornado shelter of some sort. In my youth, many people had potato cellars that served the purpose. Today, manufactured shelters are common. Mine looks like a propane tank with an end cut off, and bolted to the concrete slab using industrial concrete anchors.

I purchased a small, inexpensive electrical space heater with a fan and a thermostat, and I hope that the air circulates well enough to prevent the vapors from reaching an explosive level. Last night was chilly, and my first test appears successful. I applied a first coat of 50/50 varnish/mineral spirits to my first stick. It had been finished with 100% tung oil several years ago.

Here is my new varnish booth:

 

[Ron T]

Very ingenious, both the shelter and using it to dry your varnish.

 

[Rodney]

Great idea to use it that way. The thermostat is also a great idea. It would be very easy to overheat the drying station without it.

I guess the shelter beats getting caught in a tornado or having the house fall on you but if you're claustrophobic at all it wouldn't be a fun place to be.

Rodney

 

[cobalt]

Its a pain drying anything in the winter takes so long . I got a blow heater all it does is blows dust around and cant paint in the workshop with it.Its a real pain .but its warm whilst carving

A fume cabinet would solve the problem if I had the room which I haven't.

 

[CAS14]

I've emailed the fire department for recommendations for a safer heater. My wife says if I blow up the house, we're moving to Half Moon Bay. That's tempting as there is a great brew pub there.

 

[cobalt]

definatly go to the pub. mines a pint Guinness maybe a chaser

 

[MJC4]

I will throw this out there. I'm thinking the electric heater in a confined space will be frowned on by the Fire Dept.

Maybe duct the heat into the tank? A visqueen flap over the door and a piece of flex duct they use for bathroom exhaust vent put into the space and infront of the heater. Safer to keep the electric heater out of the confined space with the vapors from the varnish/min spirits.

 

[CAS14]

I've shopped for a heat-safe duct accompanying a heater, and I'm betting that the Tulsa Fire Department will give me some better options than my cowboy setup. Great comment MJC4!

 

[Rodney]

They make ceramic infrared heaters for reptile tanks that screw into a regular lightbulb socket. Maybe something like that if the heater doesn't work out. Given the structure it's in I think the chances of a fire actually spreading and doing any damage to anything but the paint on the shelter and the stick that's drying are slim but still who needs the hassle?

Rodney

 

[CAS14]

They make ceramic infrared heaters for reptile tanks that screw into a regular lightbulb socket. Maybe something like that if the heater doesn't work out. Given the structure it's in I think the chances of a fire actually spreading and doing any damage to anything but the paint on the shelter and the stick that's drying are slim but still who needs the hassle?

Rodney

I agree that the risk is minimal. Still, the really cheap heater that I bought says it sparks some, and to keep away from flammable things. I told my wife that I'd yell "fire in the hole" every time I start it up, but she didn't care for that response. I'm betting that there are totally safe options, and I hope to speak with a fire department expert soon about this. So far, I've had success with two applications, one 50/50 varnish/mineral spirits as a sealer, LOT's of volatile vapors, overnight. The second just varnish with far less volatile vapors, during the day today. The thermostat doesn't have a temperature gauge, it's just "low" and "high." But I was able to regulate the temperature nonetheless, to something that seems okay.

Whatever happens, it's going to be a lot easier and cheaper than insulating the entire garage. If I blow the house up and survive, then we'll wind up near a really good brew pub on the west coast. So it's a win-win situation!

 

[Whiteroselad]

I remembered watching this video some time ago on You tube, I know that it may not be strictly the same thing but it is an idea. John lives in Canada so I reckon if it works up there then it should work in most places.

Regards. N.

 

[CAS14]

Plan B

Just heard from the fire department!

I was a painter and cabinet finisher on the side so I understand about fumes trapped in a room so that the heat could help dry. From my 32 years of being a Tulsa Firefighter with 10 of them being a Fire Marshal there is nothing safe health wise of fire safety wise about having flammable vapors confined in a room. Even a light switch can ignite the fumes.

The calls that we make are when the whole room explodes and the painter is standing in the front yard Burnt to a crisp with a friend holding a garden hose cooling him down.

 

[MJC4]

Uh, I take it the Fire Dept. is not too enamored with your varnish drying idea?

I live in a bi-level home. The downstairs heat vents are in the ceiling. I have hung a stick or two off the grates in the downstairs bathroom heat vent and kept the door closed. This is after I have gotten the varnish tacky with my wife's blow dryer.

 

[CAS14]

Uh, I take it the Fire Dept. is not too enamored with your varnish drying idea?
I live in a bi-level home. The downstairs heat vents are in the ceiling. I have hung a stick or two off the grates in the downstairs bathroom heat vent and kept the door closed. This is after I have gotten the varnish tacky with my wife's blow dryer.

Could be a similar risk.

The initial sealing coat with a large cut of mineral spirits emits far, far more vapor, and I'd guess the risk is far greater. I plan to cease applying the sealing coat in cold weather. I am still looking for a safer heater, perhaps one designed to force warm air through a tube, but I'm not inclined to jury rig that. Then I'd need a thermostat controller that has a remote sensor that can reside within the enclosure, and control the heater.

I'm looking on the internet nearly every day. Lowe's, Home Depot, and Ace haven't solved the problem. I plan to check the Grainger website.

 

[Gloops]

Necessity is the mother of invention, well thought out now all you need to do is market it

 

[gdenby]

Seems to me that part of the problem is the tight seal the chamber has. Heat and vapor build-up.

Then, that the heater might spark.

So,

Find out what the flash point for the drying agent in the varnish is. Swap out the heater for a 60 - 100 watt incandescent lamp. If available, put in an oven thermometer that has an external read out in the chamber. Otherwise, check manually at intervals. Determine if the chamber reaches the flash point temperature. If it does, find out how much the chamber door needs to be cracked to keep the interior temp below the danger threshold.

Also, if I'm understanding some of what I have read about varnish drying,for some finishes it is UV exposure more than heat that hardens the finish. What may work as well is just some black light florescent tubes in a foil coated box placed somewhere the off-gassing isn't noxious to humans.

 

[CAS14]

Seems to me that part of the problem is the tight seal the chamber has. Heat and vapor build-up.

Then, that the heater might spark.

So,

Find out what the flash point for the drying agent in the varnish is. Swap out the heater for a 60 - 100 watt incandescent lamp. If available, put in an oven thermometer that has an external read out in the chamber. Otherwise, check manually at intervals. Determine if the chamber reaches the flash point temperature. If it does, find out how much the chamber door needs to be cracked to keep the interior temp below the danger threshold.

Also, if I'm understanding some of what I have read about varnish drying,for some finishes it is UV exposure more than heat that hardens the finish. What may work as well is just some black light florescent tubes in a foil coated box placed somewhere the off-gassing isn't noxious to humans.

The steel door is designed to leave about a 3/4" gap around the margins, for ventilation when you are inside the chamber during a tornado. There is a hole in the top as well, about 1" in diameter. The fumes don't seem intense when I just apply varnish. It's the sealing coat that is approx. 50/50 varnish/mineral spirits that is over the top. Oven thermometer is a good idea, but I'd like to get a thermometer that will cut the power to the heater on and off at a specified temperature, and with an external probe that can reach into the shelter. I'll read up on that UV aspect. I was going off the instructions with the varnish so far as environmental conditions.

 

[LilysDad]

That tornado shelter looks pretty small. I can just see the fight to see who gets in during a storm.

 

[gdenby]

Maybe look at something like this. Auber makes decent controllers for the price. I use one for a sous vide water bath cooker. The appliance I linked to, I think will control the power to a heating element based on the air temp the sensor reports. At any rate, look over what they offer to see what might work best.

 

[Sean]

I've emailed the fire department for recommendations for a safer heater. My wife says if I blow up the house, we're moving to Half Moon Bay. That's tempting as there is a great brew pub there.

Hopefully you wont have to delete this thread to collect on your home insurance then.