Post by Danno on May 27, 2010 17:52:21 GMT -8
I recently posted this on another board and Martay suggested I also post it here. So, by popular demand, here it is ...
[glow=red,2,300]DEHYDRATOR PRIMER[/glow]
I'm really not an "expert" but I regularly use three varieties of dehydrators and I can throw in some info.
COUNTERTOP DEHYDRATOR
The dehydrator you most commonly see mentioned for modeling is the countertop food-dryer/dehydrator that many modelers convert for use with their building/painting projects.
These guys are usually readily available at department stores (remember them?), discount giants, household goods stores, or cooking stores. The ones we tend to see most often are generally round with several removable rings that include open-lattice trays intended for placement of fruits or meats for drying. These dehydrators have a heating unit and air circulating fan built into their top covers. The best ones for adaptation to modeling also have a temperature control ~~ more on that later.
Many modelers remove the inner trays (or portions) from the rings in order to open up the interior space and allow for larger parts, components, and even bodies to be accommodated inside the dehydrator.
Placing freshly painted parts or bodies into the dehydrator is limited only by one’s imagination. I use paint can caps, bottle caps, toothpicks, various lengths of bamboo skewer sticks, double-rolled masking tape, and even my all-time favorite paint stand – a ½ full plastic water or beverage bottle.
A note about that … I attach small parts to the plastic cap of a water or beverage bottle and use it as a spray stand. Plastic bottles are plentiful, cheap, versatile and disposable when the wear out or accumulate so much overspray they’re too ugly to look at any more! I fill them 1/3 to 1/2 full of plain water to keep them weighted with a low center of gravity. If you’re concerned about humidity, you can use fine sand, although I’ve not found the water to be a problem.) They’re handy and convenient to hold while painting the part, and with the weighting, they’re stable to set down while the part dries.
Depending on how full the dehydrator will be, I can either place the entire bottle in the dehydrator or I can carefully unscrew the cap and place only it with the part attached into the dehydrator.
The key is to be certain of course to not touch the part and mar its painted surface. I always allow a few minutes for the fresh paint to flash-over before handling its carrier, whether the carrier is a bottle cap, masking tape roll, or skewer. And, using fast-flashing lacquers certainly improves the odds.
My dehydrator has a temperature control. I’ve found it best to not exceed 105 – 115 degrees with styrene parts and I keep it lower (95 – 100 degrees max) with resins because they are softer and more susceptible to warping or sagging. With diecast items, I’ll go a little higher just to accelerate the process and give it that ‘authentic’ baked-on finish.
Regardless of the material or paint, the dehydrator speeds gassing-out, drying, and curing. Especially with lacquers, you’ll get a rock-hard finish in amazingly little time!
Oh, yeah, one last thing. Don’t use the dehydrator for food after you’ve used it for paint. Or, at least don’t offer me any of your jerky or dried fruits without warning me!
UNIVERSAL DEHYDRATOR
I’ve heard some modelers grouse that they can’t afford a countertop dehydrator. Well, here’s a simple substitute. Remember --- use your imagination.
Most everybody has a handy-dandy universal dehydrator that can be placed into service for modeling needs – the kitchen oven.
I often use the kitchen oven for drying painted parts … especially bodies and other large components (semi frames, etc.) that won’t fit into my countertop dehydrator. The oven has all the same attributes of the countertop dehydrator but has much larger interior capacity. However, there is a very specific way to use the kitchen oven for drying painted model parts.
Again, place painted parts in the oven only after they’ve had a few minutes to flash dry.
Be aware that there will likely be a delightful aroma unique to model car building that will permeate your kitchen and bring pleasant thoughts to you, but may bring not-so-pleasant thoughts to the other occupants of your residence. The aroma will be stronger or weaker depending on the size and quantity of the items being dried, since the aroma will be directly proportional to the mass of the paint applied. It dissipates fairly rapidly as the paint cures, but be prepared to withstand a degree of somewhat constructive and active criticism.
WARNING -- PAY CLOSE ATTENTION TO THE FOLLOWING: DO NOT USE THE HEATING ELEMENTS OF THE OVEN. DO NOT TURN ON THE GAS OR ELECTRICITY TO THE OVEN.
Just turn on the oven light and close the door. That’s all there is to it.
The light bulb inside the oven generates enough BTUs to bring the interior temperature of the oven to 95 – 105 degrees, depending on the wattage of the bulb and the size of the oven’s interior.
Test it first. Use an oven thermometer to determine exactly how warm your kitchen oven will get over a period of time. Then, use carefully.
REMEMBER: There is at worst a severe fire hazard if you use the oven and turn on its heating elements; at best you’ll probably melt down your model or parts. Either way, it may ruin your oven, your kitchen, your house, your relationship with the little lady in your life, and perhaps even (OMG) your model.
MONGO-CAPACITY ENVIRONMENTAL DEHYDRATOR
The third dehydrator I use regularly may be somewhat unique to the Southwest: my garage, or, on windless days, the patio.
Simply put, here in the Sonoran Desert the ambient air temperature is often sufficient to quite nicely convert the entire neighborhood into a fine dehydrator. And, I’ve seldom encountered any problems fitting model car parts into the mongo-dehydrator. Plus, it is environmentally friendly and not prone to much fire hazard.
You, in your geographic area, may not have availability of the same combination of dry heat and absence of ambient humidity necessary to utilize your surroundings in the same fashion.
Remember, it’s all about a dry heat!
[glow=red,2,300]DEHYDRATOR PRIMER[/glow]
I'm really not an "expert" but I regularly use three varieties of dehydrators and I can throw in some info.
COUNTERTOP DEHYDRATOR
The dehydrator you most commonly see mentioned for modeling is the countertop food-dryer/dehydrator that many modelers convert for use with their building/painting projects.
These guys are usually readily available at department stores (remember them?), discount giants, household goods stores, or cooking stores. The ones we tend to see most often are generally round with several removable rings that include open-lattice trays intended for placement of fruits or meats for drying. These dehydrators have a heating unit and air circulating fan built into their top covers. The best ones for adaptation to modeling also have a temperature control ~~ more on that later.
Many modelers remove the inner trays (or portions) from the rings in order to open up the interior space and allow for larger parts, components, and even bodies to be accommodated inside the dehydrator.
Placing freshly painted parts or bodies into the dehydrator is limited only by one’s imagination. I use paint can caps, bottle caps, toothpicks, various lengths of bamboo skewer sticks, double-rolled masking tape, and even my all-time favorite paint stand – a ½ full plastic water or beverage bottle.
A note about that … I attach small parts to the plastic cap of a water or beverage bottle and use it as a spray stand. Plastic bottles are plentiful, cheap, versatile and disposable when the wear out or accumulate so much overspray they’re too ugly to look at any more! I fill them 1/3 to 1/2 full of plain water to keep them weighted with a low center of gravity. If you’re concerned about humidity, you can use fine sand, although I’ve not found the water to be a problem.) They’re handy and convenient to hold while painting the part, and with the weighting, they’re stable to set down while the part dries.
Depending on how full the dehydrator will be, I can either place the entire bottle in the dehydrator or I can carefully unscrew the cap and place only it with the part attached into the dehydrator.
The key is to be certain of course to not touch the part and mar its painted surface. I always allow a few minutes for the fresh paint to flash-over before handling its carrier, whether the carrier is a bottle cap, masking tape roll, or skewer. And, using fast-flashing lacquers certainly improves the odds.
My dehydrator has a temperature control. I’ve found it best to not exceed 105 – 115 degrees with styrene parts and I keep it lower (95 – 100 degrees max) with resins because they are softer and more susceptible to warping or sagging. With diecast items, I’ll go a little higher just to accelerate the process and give it that ‘authentic’ baked-on finish.
Regardless of the material or paint, the dehydrator speeds gassing-out, drying, and curing. Especially with lacquers, you’ll get a rock-hard finish in amazingly little time!
Oh, yeah, one last thing. Don’t use the dehydrator for food after you’ve used it for paint. Or, at least don’t offer me any of your jerky or dried fruits without warning me!
UNIVERSAL DEHYDRATOR
I’ve heard some modelers grouse that they can’t afford a countertop dehydrator. Well, here’s a simple substitute. Remember --- use your imagination.
Most everybody has a handy-dandy universal dehydrator that can be placed into service for modeling needs – the kitchen oven.
I often use the kitchen oven for drying painted parts … especially bodies and other large components (semi frames, etc.) that won’t fit into my countertop dehydrator. The oven has all the same attributes of the countertop dehydrator but has much larger interior capacity. However, there is a very specific way to use the kitchen oven for drying painted model parts.
Again, place painted parts in the oven only after they’ve had a few minutes to flash dry.
Be aware that there will likely be a delightful aroma unique to model car building that will permeate your kitchen and bring pleasant thoughts to you, but may bring not-so-pleasant thoughts to the other occupants of your residence. The aroma will be stronger or weaker depending on the size and quantity of the items being dried, since the aroma will be directly proportional to the mass of the paint applied. It dissipates fairly rapidly as the paint cures, but be prepared to withstand a degree of somewhat constructive and active criticism.
WARNING -- PAY CLOSE ATTENTION TO THE FOLLOWING: DO NOT USE THE HEATING ELEMENTS OF THE OVEN. DO NOT TURN ON THE GAS OR ELECTRICITY TO THE OVEN.
Just turn on the oven light and close the door. That’s all there is to it.
The light bulb inside the oven generates enough BTUs to bring the interior temperature of the oven to 95 – 105 degrees, depending on the wattage of the bulb and the size of the oven’s interior.
Test it first. Use an oven thermometer to determine exactly how warm your kitchen oven will get over a period of time. Then, use carefully.
REMEMBER: There is at worst a severe fire hazard if you use the oven and turn on its heating elements; at best you’ll probably melt down your model or parts. Either way, it may ruin your oven, your kitchen, your house, your relationship with the little lady in your life, and perhaps even (OMG) your model.
MONGO-CAPACITY ENVIRONMENTAL DEHYDRATOR
The third dehydrator I use regularly may be somewhat unique to the Southwest: my garage, or, on windless days, the patio.
Simply put, here in the Sonoran Desert the ambient air temperature is often sufficient to quite nicely convert the entire neighborhood into a fine dehydrator. And, I’ve seldom encountered any problems fitting model car parts into the mongo-dehydrator. Plus, it is environmentally friendly and not prone to much fire hazard.
You, in your geographic area, may not have availability of the same combination of dry heat and absence of ambient humidity necessary to utilize your surroundings in the same fashion.
Remember, it’s all about a dry heat!