# Homemade Tools > Basic Homemade Tools and Tips >  Dry spray paint in 20 minutes.

## mr_modify1

Great for smaller pieces of metal.

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Floradawg (Dec 18, 2021),

johncg (Dec 16, 2021),

justintjm (Feb 24, 2022),

nova_robotics (Dec 16, 2021)

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## nova_robotics

I hate to be that guy, but I hear this repeated on jobsites all the time. The moisture isn't coming out of the metal. Craft guys will swear up and down there's water in steel, and that a torch makes it come out. There is no water in steel. 

I have a cheapo digital heat gun. You can just set the temperature on a little LCD display on the back. It's pretty handy. I've used it to cure JB Weld and paint super fast many times. I'm sure the NACE inspector would have something to say about it though.

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Beserkleyboy (Dec 16, 2021),

mwmkravchenko (Dec 19, 2021),

sparky42 (Dec 16, 2021)

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## Beserkleyboy

Yup...I think he was absent that day when the physics class studied humidity and condensation...and EVERY tin of paint, anywhere in the world has min & max temps specified, based on not just ambient temperature, but accepting that the substrate to be painted is at equilibrium with the ambient temp...good thing he's probably not guaranteeing his hobby work...

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## sossol

> I hate to be that guy, but I hear this repeated on jobsites all the time. The moisture isn't coming out of the metal. Craft guys will swear up and down there's water in steel, and that a torch makes it come out. There is no water in steel. 
> 
> I have a cheapo digital heat gun. You can just set the temperature on a little LCD display on the back. It's pretty handy. I've used it to cure JB Weld and paint super fast many times. I'm sure the NACE inspector would have something to say about it though.



This is the first I've heard the notion that water is *in* the metal. Maybe he meant on, but misspoke. 

I'll admit that it's pedantic, but my pet peeve is usage of the term "drying". Except water-based paints (tempura, gauche, etc.), paint doesn't dry - it cures. In most cases heat accelerates the chemical process. 

A quartz heat lamp would give the same results as far as a faster curing time after painting, but I've used this pre-heat trick. It does work. Letting parts sit on a heater that's in use anyhow works a treat.


Neil

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## NortonDommi

"Letting parts sit on a heater that's in use anyhow works a treat." bought back a memory of last century when a place I worked at had an old bar heater used to warm bits up before application of high heat wrinkle paint,(great stuff to cover up after fabrication without a lot of finishing work), and we used to heat the bits, remove the rack and apply paint from an aerosol can. We did this in the store room.
One day apprentice decided to much hassle to move the rack so started spraying while the heater was on. Flames made him drop the can into the heater.
The fire was put out but he had a LOT of cleaning up to do.

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## Frank S

> "Letting parts sit on a heater that's in use anyhow works a treat." bought back a memory of last century when a place I worked at had an old bar heater used to warm bits up before application of high heat wrinkle paint,(great stuff to cover up after fabrication without a lot of finishing work), and we used to heat the bits, remove the rack and apply paint from an aerosol can. We did this in the store room.
> One day apprentice decided to much hassle to move the rack so started spraying while the heater was on. Flames made him drop the can into the heater.
> The fire was put out but he had a LOT of cleaning up to do.



Sounds like the apprentice was not ready for unsupervised work.

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mwmkravchenko (Dec 19, 2021)

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## nova_robotics

> This is the first I've heard the notion that water is *in* the metal. Maybe he meant on, but misspoke.



It's a very common myth all across Canada and the US with tradesmen. They call it "sweating out" the steel. They will swear up and down that there's water in steel, and that a torch makes the water come out. I've gotten into a number of arguments about this. 

Also extremely common:

Gasses don't weigh anything. For example, a full bottle of argon will weigh the same as an empty one. 

If you put an extension on a socket it will somehow make the torque "go away," and you need to increase the setting on your torque wrench. This one really gets me because guys overtorque bolts ALL THE TIME, sometimes to the point of snapping the heads off because the torque "disappears" inside the extension for some reason. If a bolt needs 100 lbs-ft of torque, you can be guaranteed that the tradesmen will tack on at least another 25-30 lbs-ft if they're using an extension. This isn't just common it's basically a rule among the trades. Drives me nuts.

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## sossol

> It's a very common myth all across Canada and the US with tradesmen. They call it "sweating out" the steel. They will swear up and down that there's water in steel, and that a torch makes the water come out. I've gotten into a number of arguments about this.




I'd always assumed that sweating the steel was rhetorical, since it resembles sweat. 


Neil

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## Rangi

Are you using the term "trades" loosely.  :Smile:

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## mr_modify1

Yes you are correct it only looks like it is coming out of the metal but really is condensation. If the metal were damp it would be dry after the heating. Regardless of any water coming from anywhere this process really works to give you a dry paint in about 20 minutes.

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## nova_robotics

> Are you using the term "trades" loosely.



Well it doesn't apply to the sparkies or tin bashers. It definitely applies to the iron workers, welders and millwrights though.

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## mr_modify1

Sorry don't remember mentioning trades in this video.

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## nova_robotics

> Sorry don't remember mentioning trades in this video.



No not at all. But that's the ONLY place I've heard sweating steel repeated.

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## mwmkravchenko

> It's a very common myth all across Canada and the US with tradesmen. They call it "sweating out" the steel. They will swear up and down that there's water in steel, and that a torch makes the water come out. I've gotten into a number of arguments about this. 
> 
> Also extremely common:
> 
> Gasses don't weigh anything. For example, a full bottle of argon will weigh the same as an empty one. 
> 
> If you put an extension on a socket it will somehow make the torque "go away," and you need to increase the setting on your torque wrench. This one really gets me because guys overtorque bolts ALL THE TIME, sometimes to the point of snapping the heads off because the torque "disappears" inside the extension for some reason. If a bolt needs 100 lbs-ft of torque, you can be guaranteed that the tradesmen will tack on at least another 25-30 lbs-ft if they're using an extension. This isn't just common it's basically a rule among the trades. Drives me nuts.



One of Propane's by products as it burns is water vapour. You are actually condensing the water onto the cool steel. 

I hear you on the misapplication of torque wrenches as well. I have had those conversations. Go to where? Now there is a little loss in the sockets between the extension and the socket end. But not that much. A few percent at the most. Actually thinking this through that may be erroneous as well. If the rotation is blocked where in the ratchet - extension - and then socket is the torque disappearing to? Potential twist in the extension shaft. That is about it as far as I can think through.

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nova_robotics (Dec 19, 2021)

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## nova_robotics

> Now there is a little loss in the sockets between the extension and the socket end. But not that much. A few percent at the most. Actually thinking this through that may be erroneous as well. If the rotation is blocked where in the ratchet - extension - and then socket is the torque disappearing to? Potential twist in the extension shaft. That is about it as far as I can think through.



I actually worked this out one day and it's pretty interesting. 

If you're using an impact then the "springiness" of the extension will limit the torque at the bolt. The extension is essentially a torsion rod and the impact is energy (or impulse?) limited. So some of that energy will go into doing work on the torsion rod instead of being transferred to the bolt. Somebody has already noticed this and turned it into a product. You can buy torque limiting extensions off the shelf. 

BUT! If you look at what happens at the extension when you have a conventional torque wrench on there, the extension is sloppy at both end connections. It will bend over a few degrees in the direction of the force applied. That actually *increases* the effective lever arm distance between the point load (your hand) and the bolt. So if your torque wrench is set to exactly 100 lbs-ft, the fastener will experience a slightly greater torque, say 102 lbs-ft. The effect is small, only a few percent. But still. Opposite to what everyone assumes will happen.

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mwmkravchenko (Dec 19, 2021)

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## sossol

> If you're using an impact then the "springiness" of the extension will limit the torque at the bolt. The extension is essentially a torsion rod and the impact is energy (or impulse?) limited. So some of that energy will go into doing work on the torsion rod instead of being transferred to the bolt. Somebody has already noticed this and turned it into a product. You can buy torque limiting extensions off the shelf.



I've long wondered how those work. I understand the torsion rod principle (anyone who has fought a stubborn bolt would), but not how that ultimately limits rotation. Obviously the smaller diameter takes less torque to twist up, but that's where my understanding ends. It seems to me that the rod would store the energy until it reaches its limit, then stop twisting and transfer it on to the socket.

Neil

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## Tooler2

I like to spray paint on fresh welds while they are hot, the first coat may blacken but another quick coat a few minutes later covers that.
socket extensions eat a lot of torque on an impact gun, should not affect a manual torque wrench.

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mwmkravchenko (Dec 20, 2021)

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## DIYer

Thanks mr_modify1! We've added your Rapid Paint Drying Method to our Painting category,
as well as to your builder page: mr_modify1's Homemade Tools. Your receipt:















Rapid Paint Drying Method
 by mr_modify1

tags:
painting

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