Using a Food Dehydrator to cure paint quicker

[adampolo13]

Okay, does anybody here use an electric food dehydrator to help cure paint faster? I've seen it on a few YouTube videos and I am curious.

Thanks,

Adam

 

[Elm City Hobbies]

I don't personally, but a friend of mine does and swears by it.

 

[spud]

Hair Dryer??

 

[adampolo13]

Hey spud, not a hair dryer, an electric food dehydrator. People use them to cure paint faster/

 

[spud]

lol no i ment use one ;D should of made it more clear, its what i use if i want to speed things up, but mainly for acrylics

 

[adampolo13]

The thing I heard about the hair dryer was that it doesn't evenly cure the paint. The dehydrator sucks the moisture out of the paint, i.e. cures it. I just wasnt sure if anbody here used one. There is very little info available online about it...

 

[Elm City Hobbies]

Yeah dehydrator helps cure the paint, hair dryer (which I use now and again) will allow you to dry the paint enough that you can continue painting, and not have to wait for the paint to dry to continue.

 

[spud]

the hair dryer wont cure teh paint 100% but ut cures it enough so you can continue to work

 

[C.A. Whitecloud]

If I'm using my dehydrator, do I "pop" the body in and out between overlapping coats? For like 2 minutes, or what? I'm using Tamiya rattle cans for color and Rustoleum primer. It's the first time using the dehydrator. At the moment I'm using the "Paint out the back door" method cause it's cold to leave the piece outside. Is it possible to get any interim coat TOO dry for successive coats, and what might be possible unfortunate outcomes to look out for? Cheers.

 

[Littlemarten]

I also do this.
Paint doesn't just "dry," it cures. Curing is a chemical reaction, and while it can be accelerated by heat, too much, too soon, will result in a weak film.
The best method is to paint the model, then wait until the paint is "tack free," meaning that a light touch will not mar the paint. To be certain, paint a piece of scrap at the same time, a piece of sprue will do. When you can handle the sprue without leaving marks on the surface, the paint is tack free. At that point, you can put it in the dehydrator for an hour at 130°F for an hour.

Gloss paint requires a longer time to become tack free, especially in thick coats.

 

[ssgteverett]

Or one can use a simple cardboard box, an incandescent light bulb 40 - 75 watts max [that's if you can find any] and mount the bulb and light socket fixture inside and voila', you have a 'paint drying oven' - Been using this 'oven' now for over 50+ yrs and never had an issue; Works with models - figures - ground work - whatever. AND if something to large for the basic 'oven', get yourself a larger box. I've never 'melted' anything nor burned-my-house-down and its cheap and simple [and a case of 60w bulbs to boot]. - Just a thought

 

[Edbert]

I bought one years ago for making jerky, I have used it on a model before, even recently.

I do not think it is needed for Tamiya Acrylics, from an airbrush that stuff it dry about the time it hits plastic. Exaggerating but not much.

I did use it on the McLaren I'm building, used Gravity (brand) paints on it so am being extra careful.

One thing for the experts...I thought curing meant that all of the gasses were out. If you get it dry to the touch (not fully dried) and then put more layers of wet paint down, are you not doing that before the 1st layer is completely dry/cured?

 

[Littlemarten]

I bought one years ago for making jerky, I have used it on a model before, even recently.

I do not think it is needed for Tamiya Acrylics, from an airbrush that stuff it dry about the time it hits plastic. Exaggerating but not much.

I did use it on the McLaren I'm building, used Gravity (brand) paints on it so am being extra careful.

One thing for the experts...I thought curing meant that all of the gasses were out. If you get it dry to the touch (not fully dried) and then put more layers of wet paint down, are you not doing that before the 1st layer is completely dry/cured?

It can be difficult to determine the difference between "tack-free" and fully cured. When in doubt, wait longer before masking or applying another coat.

Liquid paint is composed of:
A binder—the film-forming component that holds the pigment. In a liquid paint, it is dissolved in the solvent.
Pigment—the coloring material and other insoluble materials.
Solvent—this is what makes paint liquid. It can be a single material or a blend. Many paints contain a blend of solvents with different evaporation rates.

The problem here is the word "dry." Here's what happens when you apply a coat of paint:

1. Paint reaches surface in a liquid state and flows slightly to form a smooth, continuous coating.
2. The paint's solvents begin moving toward the free, exposed surface where they evaporate. How long this process takes depends on the solvent type, the thickness of the coating, the temperature, and the viscosity of the paint.
3. As the solvent leaves, polymerization of the binder—the film forming component of the paint—begins. This is the process generally called "curing."
4. Most or all of the solvent has left the paint. Polymerization continues. This is "tack free." The paint is NOT "dry," though it is dry to touch. How long polymerization continues is determined by the chemical composition of the binder and the ambient temperature.
5. Polymerization is complete. The paint is now "dry."

If another coat of paint is applied before number 4, above, problems can result. These include, but are not limited to blistering, prolonged curing time (days), alteration of surface characteristics (especially in gloss and semi-gloss paints.)

Gloss and semigloss paints take longer to cure. (A word about Tamiya and Gunze gloss paints: they contain a silicone component that migrates to the surface and will interfere with the bond of subsequent coats once they are fully cured. A quick wipe with an alcohol dampened cloth before overcoating will usually solve the problem.)

If brush painting, it is best to wait until you are sure curing is complete. (If you are in a hurry, you're in the wrong hobby.) This is because brush painting generally results in a much thicker coating.

Common wisdom with airbrushing is to apply multiple, thin coats. This means you can apply another coat almost immediately, as soon as the surface no longer appears wet. But you have to be careful to keep the subsequent coats thin. This becomes a matter of experience, but it is different for every brand of paint.

So how long to wait? It's a matter of experience. With the exception noted above for some gloss paints, when in doubt, wait overnight. This is a hobby. Hobbies should not have deadlines.

 

[C.A. Whitecloud]

I bought one years ago for making jerky, I have used it on a model before, even recently.

I do not think it is needed for Tamiya Acrylics, from an airbrush that stuff it dry about the time it hits plastic. Exaggerating but not much.

I did use it on the McLaren I'm building, used Gravity (brand) paints on it so am being extra careful.

One thing for the experts...I thought curing meant that all of the gasses were out. If you get it dry to the touch (not fully dried) and then put more layers of wet paint down, are you not doing that before the 1st layer is completely dry/cured?

Is it cool to put Tamiya masking tape in the oven?
*I meant the dehydrator...just being silly.

 

[Littlemarten]

Is it cool to put Tamiya masking tape in the oven?

No. We aren't talking about an oven, rather a food dehydrator that doesn't get anywhere near as hot.

 

[Edbert]

No. We aren't talking about an oven, rather a food dehydrator that doesn't get anywhere near as hot.

I'm not sure HOW hot mine can get, but it has a digital thermostat so I can dial it in by single degrees, and I know it goes over 250 degrees if I want. For plastic I keep it under 120, period. I think 180 might be okay but why push it. If the total time setting is under 6 hours I'll set it at 110 degrees, if I'm going for a 24 hour drying session (rare) I will drop to 100 or 105. I do not think that is needed, just paranoid.

I'd never put it in the dehydrator with the tape on though, I'd be worried about what happens to the adhesive. Decals are safe though.

I'm gonna make some banana chips today, there are three of them with black spots that are getting too large for my taste. Recipe (yes) calls for 6-8 hours at 135 degrees.

 

[Littlemarten]

What camo scheme are you using on the banana chips?

 

[Jim62]

I'm not sure HOW hot mine can get, but it has a digital thermostat so I can dial it in by single degrees, and I know it goes over 250 degrees if I want. For plastic I keep it under 120, period. I think 180 might be okay but why push it. If the total time setting is under 6 hours I'll set it at 110 degrees, if I'm going for a 24 hour drying session (rare) I will drop to 100 or 105. I do not think that is needed, just paranoid.

I'd never put it in the dehydrator with the tape on though, I'd be worried about what happens to the adhesive. Decals are safe though.

I'm gonna make some banana chips today, there are three of them with black spots that are getting too large for my taste. Recipe (yes) calls for 6-8 hours at 135 degrees.

I have a round dehydrator you can by at the sporting goods store. Set it at 105 then cook for 4 to 5 hours and it works great for me with Tamiya acrylics. It won't work for large models but 1/48th scale WWII fighters and anything else in that size range fit in it.