# How cold can I spray latex paint?



## Oh-Fudge (Sep 1, 2011)

I need to paint some metal radiator covers and some beadboard with latex interior paint using a spray gun. Problem is, I need to do it outside in my barn which is unheated, and just my luck, the local temperature is going down into the 40's for the first time this year this weekend! My question is - How low a temp can I still spray paint without problems? Do I need to thin it a little extra to reduce the viscosity? Any other things I should do for cold weather spray painting? Thanks!!


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## jschaben (Mar 31, 2010)

Oh-Fudge said:


> I need to paint some metal radiator covers and some beadboard with latex interior paint using a spray gun. Problem is, I need to do it outside in my barn which is unheated, and just my luck, the local temperature is going down into the 40's for the first time this year this weekend! My question is - How low a temp can I still spray paint without problems? Do I need to thin it a little extra to reduce the viscosity? Any other things I should do for cold weather spray painting? Thanks!!


I haven't really done any cold weather spraying. Can will sometimes list a minimum application temperature. I'd use that. Seems most that have it say 35*F but I'd hold off it it looks like it will go below that withing the next 24 hrs. JMHO


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## Brushjockey (Mar 8, 2011)

Depends on the paint. You could read the can. It will tell you.
( I know- so simple- but it works!)


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## Oh-Fudge (Sep 1, 2011)

Thanks Brushjockey. I'm going to take your comment as a serious answer and not that you are being a smartass, I hope. Yes, I learned to read a couple of years ago. I was posting this question to get a "real life" opinion from painting pros. Perhaps I am not the first one to notice that the "directions on the can" are often more flexible than they are willing to print, due to legal restrictions, etc. Plus, I am not a professional painter and do not know if there are any special considerations for spraying rather than brushing at lower temps. Such as - does one need to thin the pain more for colder temps, etc.

Any useful advice is much appreciated. Thanks.


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## jschaben (Mar 31, 2010)

Oh-Fudge said:


> Thanks Brushjockey. I'm going to take your comment as a serious answer and not that you are being a smartass, I hope. Yes, I learned to read a couple of years ago. I was posting this question to get a "real life" opinion from painting pros. Perhaps I am not the first one to notice that the "directions on the can" are often more flexible than they are willing to print, due to legal restrictions, etc. Plus, I am not a professional painter and do not know if there are any special considerations for spraying rather than brushing at lower temps. Such as - does one need to thin the pain more for colder temps, etc.
> 
> Any useful advice is much appreciated. Thanks.


I got to thinking about this, not always a good thing:wink: Since most latex paints (if not all) have ethelyne glycol in them which is also an antifreeze, I doubt you will have viscosity problems. Any issues would likely be from the drying/curing standpoint. If you need to thin, I think I would use a conditioner instead of water. The air temp itself may not mean much either, the object you're painting needs to be in the correct temperature range. Could be colder than the air temp. Just a couple of random thoughts from a wandering mind.


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## user1007 (Sep 23, 2009)

Why not space heat a part of the barn and not worry. A little ceramic heater and some plastic would work. Provide adequate ventilation of course. Nothing more fun than watching paint dry. Except watching it dry when it is cold enough it does not want to cure.

And just a madcap suggestion? I got in the habit of taking radiators I wanted to look nice in restorations for sandblasting and then to the body shops and high heat engine painting guys around town. Cost less than messing with it all myself.


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## ben's plumbing (Oct 6, 2011)

just a thought we did this one time to finish off a kitchen we installed and needed to paint the trim and leave dry before install...we made a small tent out of plastic in used a small electric heater.....worked great......not sure how perfect you want you job?????just a thought????


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## Oh-Fudge (Sep 1, 2011)

Thanks jschaben, sdsester and ben. I like the space heater idea. And yes, the metal might be colder than the air temp, good thought! These are the covers for baseboard hot water heat - long and thin, these don't get very hot in use cuz it's hot water not steam heat, and they aren't in direct contact with the water pipe & fins. I recall that most paint says to use "above 50-55 degrees", just my luck the weatherman predicts temps in the 40's the weekend I want to paint . So I'm hopin' that I can fudge the minimum temp a little!


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## oh'mike (Sep 18, 2009)

55 is usually the coldest safe temperature----The paint cures so slowly when cold that runs become a huge problem.


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## Brushjockey (Mar 8, 2011)

Not completely being a smart ass- but some people expect us to answer questions without making any attempt at the obvious- Good to see you are actually working the problem.
The tent/ heater idea is a good one. When the temps are close- it doesn't take much. I did a few jobs that using a halogen lamp in a confined space was enough to tip the temp to acceptable range. 
Just be careful that the heater- whatever source you use- is placed safely.


There are also paints ( mainly exterior rated- because that is where the issue usually is) that are rated to 35. Best to ask at a good paint store- they should be able to guide you to the right product.


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## user1007 (Sep 23, 2009)

Brushjockey said:


> Good to see you are actually working the problem.
> Best to ask at a good paint store- they should be able to guide you to the right product.


Leaves me speechless. Dead on. :thumbsup:


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## Justgaff (Oct 8, 2011)

I've sprayed in the cold. Heat the paint n a crock pot and make sure the stuff you're painting is coming fom the war, house/shop/etc. it will help speed the dry/tack time and you can bring the items back into a warm space once they've flashed off... 

Poly and space heating works too with the above...


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## chrisn (Dec 23, 2007)

Brushjockey said:


> Not completely being a smart ass- but some people expect us to answer questions without making any attempt at the obvious- Good to see you are actually working the problem.
> The tent/ heater idea is a good one. When the temps are close- it doesn't take much. I did a few jobs that using a halogen lamp in a confined space was enough to tip the temp to acceptable range.
> Just be careful that the heater- whatever source you use- is placed safely.
> 
> ...


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## mustangmike3789 (Apr 10, 2011)

All of the points mentioned above are very good. Paint can lables are normally pretty generic forms of information, better directions can be found on the product data sheets for the paint that you are using. Applying paint outside of its range of conditions can create problems that can be diffcult to correct. Ethylene glycol will sit on the surface of the paint in cold conditions as it cures and will appear as if you sprayed antifreeze over the finish. The temporary heated spray booth is a good way to bring the paint, surface and ambient temps to acceptable levels and reduce the chance off contaminates from getting into the wet film as the paint cures at a slower rate. Dew point temp is also a problem in colder enviroments. I'm going to guess that you dont have a sling psychrometer to measure dew point and relative humidity. You can measure your dew point temp with a metal can, thermometer and ice water (salt can be added to the water in cooler weather to help lower the water temp below the ambient temp). Fill your can with water and add ice while stirring it with your thermometer to keep the can and water temp the same. As soon as you see condensation form on the can, record the temp and that will be your dew point temp. the surface temp of what you are painting should be at least 5 degrees above your dew point temp. Applying paint below the dew point will allow moisture to condense on the surface and ruin your paint job and every thing down hill from it as the paint washes away.


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## chrisn (Dec 23, 2007)

mustangmike3789 said:


> All of the points mentioned above are very good. Paint can lables are normally pretty generic forms of information, better directions can be found on the product data sheets for the paint that you are using. Applying paint outside of its range of conditions can create problems that can be diffcult to correct. Ethylene glycol will sit on the surface of the paint in cold conditions as it cures and will appear as if you sprayed antifreeze over the finish. The temporary heated spray booth is a good way to bring the paint, surface and ambient temps to acceptable levels and reduce the chance off contaminates from getting into the wet film as the paint cures at a slower rate. Dew point temp is also a problem in colder enviroments. I'm going to guess that you dont have a sling psychrometer to measure dew point and relative humidity. You can measure your dew point temp with a metal can, thermometer and ice water (salt can be added to the water in cooler weather to help lower the water temp below the ambient temp). Fill your can with water and add ice while stirring it with your thermometer to keep the can and water temp the same. As soon as you see condensation form on the can, record the temp and that will be your dew point temp. the surface temp of what you are painting should be at least 5 degrees above your dew point temp. Applying paint below the dew point will allow moisture to condense on the surface and ruin your paint job and every thing down hill from it as the paint washes away.


 
I thought everybody had one of those:laughing:


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## jschaben (Mar 31, 2010)

chrisn said:


> I thought everybody had one of those:laughing:


I used to, loaned it to my neighbor:whistling2:


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## mustangmike3789 (Apr 10, 2011)

Believe it or not, I have 2 or 3 of them.


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## chrisn (Dec 23, 2007)

mustangmike3789 said:


> Believe it or not, I have 2 or 3 of them.


Oh, I believe you do, me, I never heard of it.:no:


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## Matthewt1970 (Sep 16, 2008)

mustangmike3789 said:


> All of the points mentioned above are very good. Paint can lables are normally pretty generic forms of information, better directions can be found on the product data sheets for the paint that you are using. Applying paint outside of its range of conditions can create problems that can be diffcult to correct. Ethylene glycol will sit on the surface of the paint in cold conditions as it cures and will appear as if you sprayed antifreeze over the finish. The temporary heated spray booth is a good way to bring the paint, surface and ambient temps to acceptable levels and reduce the chance off contaminates from getting into the wet film as the paint cures at a slower rate. Dew point temp is also a problem in colder enviroments. I'm going to guess that you dont have a sling psychrometer to measure dew point and relative humidity. You can measure your dew point temp with a metal can, thermometer and ice water (salt can be added to the water in cooler weather to help lower the water temp below the ambient temp). Fill your can with water and add ice while stirring it with your thermometer to keep the can and water temp the same. As soon as you see condensation form on the can, record the temp and that will be your dew point temp. the surface temp of what you are painting should be at least 5 degrees above your dew point temp. Applying paint below the dew point will allow moisture to condense on the surface and ruin your paint job and every thing down hill from it as the paint washes away.


Or you can check the weather forcast :yes:

But a good point about the dew. All you need is to have dew form on the paint before it has sufficently dried and you will have the igredients of the paint start to leech out and wreck your paint job.


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## Oh-Fudge (Sep 1, 2011)

mustangmike3789 said:


> Ethylene glycol will sit on the surface of the paint in cold conditions as it cures and will appear as if you sprayed antifreeze over the finish. I'm going to guess that you dont have a sling psychrometer to measure dew point and relative humidity.


Wow Mike, you've probably forgot more about paint than I'll ever know. I was really hoping for an easy "insider trick" like - "put some peanut butter in the paint and it's good down to -10 degrees" , but I guess there are no shortcuts. 

I'm hoping we get up to 55 degrees at least one more weekend this year. Otherwise it's space heaters or wait until Spring time .

Ok, I'll risk asking an admittedly dumb question here, is there any danger of explosion being in an enclosed space, with an ignition source (space heater) and aerosolized paint? Yes, I know latex paint is nonflammable, but some "nonflammable" things can explode when aerosolized.....

http://en.wikipedia.org/wiki/Dust_explosion

Thanks to all for your input :yes:


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## jschaben (Mar 31, 2010)

Oh-Fudge said:


> Wow Mike, you've probably forgot more about paint than I'll ever know. I was really hoping for an easy "insider trick" like - "put some peanut butter in the paint and it's good down to -10 degrees" , but I guess there are no shortcuts.
> 
> I'm hoping we get up to 55 degrees at least one more weekend this year. Otherwise it's space heaters or wait until Spring time .
> 
> ...


How are they "aerosolized"? I don't believe I've ever seen a latex paint in a rattle can. Mostly depends on the propellant which should be listed on the can. Some, a lot, list propane.. some list several different formulations of propane. In any case a fire/explosion cautions should be on the label somewhere. If you are spraying latex with an airless or HVLP with no flammible components added, you could probably put a fire out with it.


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## Oh-Fudge (Sep 1, 2011)

Maybe I used the wrong term. Partical-ized? I didn't mean a propellant. Anyway, look at the link. Stuff like baking flour or grain can explode if a lot of it is airborne in small particles. And the last time I spray painted the room was foggy with paint particles.


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## jschaben (Mar 31, 2010)

Oh-Fudge said:


> Maybe I used the wrong term. Partical-ized? I didn't mean a propellant. Anyway, look at the link. Stuff like baking flour or grain can explode if a lot of it is airborne in small particles. And the last time I spray painted the room was foggy with paint particles.


HI Fudge - I think the term you're lookin for is atomized. You needn't be worried about about atomized latex paint as the volume is mostly water. Same stuff firefighters use in their foggers. Grain dust is dangerous because the grain, and dust is maintained at the lowest possible moisture level to prevent molding hence the dust is extremely dry. Even in high school physics when demonstrating grain dust explosions we would generally bake the flour used in the demonstration for 30 40 minutes at about 200*F to ensure it was dry enough for an effective demonstration. Problem with news coverage today is to much flair and not enough fact

Atomized oil base products are inherently dangerous as the material being atomized is highly flammible which puts the fuel/oxygen ratio in the danger zone. Matchs and cigarettes can actually be extinquished in gasoline if you can penetrate the vapor barrier above the liquid before getting 3rd degree burns. At one time my father actually welded leaks in full gas tanks. Something OSHA would likely frown on today.


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## chrisn (Dec 23, 2007)

jschaben said:


> HI Fudge - I think the term you're lookin for is atomized. You needn't be worried about about atomized latex paint as the volume is mostly water. Same stuff firefighters use in their foggers. Grain dust is dangerous because the grain, and dust is maintained at the lowest possible moisture level to prevent molding hence the dust is extremely dry. Even in high school physics when demonstrating grain dust explosions we would generally bake the flour used in the demonstration for 30 40 minutes at about 200*F to ensure it was dry enough for an effective demonstration. Problem with news coverage today is to much flair and not enough fact
> 
> Atomized oil base products are inherently dangerous as the material being atomized is highly flammible which puts the fuel/oxygen ratio in the danger zone. Matchs and cigarettes can actually be extinquished in gasoline if you can penetrate the vapor barrier above the liquid before getting 3rd degree burns. At one time my father actually welded leaks in full gas tanks. Something OSHA would likely frown on today.[/quote]
> I sure would'nt have been close enough to watch.:whistling2:


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## jschaben (Mar 31, 2010)

chrisn said:


> jschaben said:
> 
> 
> > HI Fudge - I think the term you're lookin for is atomized. You needn't be worried about about atomized latex paint as the volume is mostly water. Same stuff firefighters use in their foggers. Grain dust is dangerous because the grain, and dust is maintained at the lowest possible moisture level to prevent molding hence the dust is extremely dry. Even in high school physics when demonstrating grain dust explosions we would generally bake the flour used in the demonstration for 30 40 minutes at about 200*F to ensure it was dry enough for an effective demonstration. Problem with news coverage today is to much flair and not enough fact
> ...


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## Oh-Fudge (Sep 1, 2011)

Well, we hit 55 degrees last weekend and I gave it a shot. Put two coats on the radiator covers and some door casing. No drips, runs, spots or bursting into flames. I used a plastic dropcloth to form a 2-sided "wall", and a small space heater until they cured enough to take back into the house because the sun was setting and it was getting chilly again. Thanks everybody :thumbsup:


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## jeffnc (Apr 1, 2011)

Guess you're done. Someone mentioned Resilience, which is exterior paint rated down to 35 degree application. I was assuming that referred to drying/curing, but my worry would be how the paint would flow through a sprayer at that temperature. The spec sheet for Resilience allows for sprayer application at 2000 psi and .015 - .019 tip size with no other mention, so the implication is that it's formulated to flow fine through a sprayer at those temperatures.


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## Oh-Fudge (Sep 1, 2011)

2000psi  Holy Smoke! I could get peanut butter to flow thru a sprayer at that pressure! I'm guessing that stuff is for industrial applications? My paint gun runs at 40-60 psi.

I was wondering if there was an additive one could add to the paint to make it flow better at lower temps, but nobody mentioned that so I figured there was no such thing.


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## jeffnc (Apr 1, 2011)

Floetrol claims it does, but I've never tried it for low temps.


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## jschaben (Mar 31, 2010)

Oh-Fudge said:


> 2000psi  Holy Smoke! I could get peanut butter to flow thru a sprayer at that pressure! I'm guessing that stuff is for industrial applications? My paint gun runs at 40-60 psi.
> 
> I was wondering if there was an additive one could add to the paint to make it flow better at lower temps, but nobody mentioned that so I figured there was no such thing.


2-3,000 psi is the norm for airless sprayers. Mine runs 2800.


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## jeffnc (Apr 1, 2011)

I guess I assumed from your post you had an airless sprayer because you were talking about latex. Even a Wagner Power Painter runs at 2,200 I think. Mine goes up to 3,000 and it's not close to industrial. What sort of sprayer are you talking about?


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## Oh-Fudge (Sep 1, 2011)

This one: Titan Vaper 19418 Siphon Feed Spray Gun

*Quick Overview*

The Titan siphon feed spray gun features a 1.8mm fluid nozzle and needle, making it ideal for spraying heavier materials.

*Details*

Model-19418.
1.8 mm fluid nozzle and needle.
Ideal for spraying heavier materials.
Fully adjustable spray pattern.
External mix for fine atomization.
33 oz. aluminum paint canister.
1/4 in. inlet.
4–7 CFM.
50–60 PSI.


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## jschaben (Mar 31, 2010)

Oh-Fudge said:


> This one: Titan Vaper 19418 Siphon Feed Spray Gun
> 
> *Quick Overview*
> 
> ...


Need an air compressor to run that. Airless pumps the paint through.


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## jeffnc (Apr 1, 2011)

jschaben said:


> Need an air compressor to run that.


That would explain the failure to pump at 3,000 psi


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