Washing a new model

I've never washed a new model, does it really make any difference??
It depends on the kit manufacturer, how oily your fingers are, and what you plan to use to paint it.

Some kit manufacturers leave a lot of mold release on the kit surface, which definitely interferes with paint bond.

How oily your hands are tends to vary both with the individual and the time of day. My hands tend to be very dry, thanks to years of exposure to alkali dust, yet there are times when I can see my oily fingerprints on a bare plastic part. Of course, if you wear gloves while assembling a model, it won't matter. (Yes, there are people who do.) Skin oil can interfere with paint bond.

Finally, what type of paint will you use?

Organic solvent paints (e.g., enamels) contain solvents that readily dissolve skin oil and some release agents (thus incorporating them into the paint, possibly with bad effects.) This includes paints like Tamiya and Gunze, which use alcohol solvents.

Aqueous (water) solvent paint systems are much more vulnerable to surface contamination, though some are more resistant than others.

As I use aqueous paints, I always wash or clean the model parts before assembly, and give the finished model a wipe down with either ethyl or isopropyl alcohol as Edbert does. I do use the concentrated alcohols, however. 90% isopropyl is available in most drug stores or online. For ethyl alcohol, I use Everclear™ 90%. You can also use "denatured" ethyl alcohol. For my reasons, see my reply to Edbert.
 
I will wipe down the surface with a heavy dose of isopropyl, just the grocery store stuff not the industrial or shop type which is stronger. Only reason is to remove fingerprints and such before the paint goes down to avoid issues.

IPA is not beer, right?

(https://www.britannica.com/topic/India-pale-ale)
I don't think washing the kit in beer would be a good idea, but I also wipe down the model with alcohol before painting for the same reason as you.

However, I use the concentrated stuff, especially isopropyl alcohol, sometimes abbreviated as "IPA.":D The reason? Common rubbing alcohol is usually isopropyl, 70% concentration. It is made by diluting 90% with tap water. While tap water may be safe to drink (YMMV) it often contains quite a lot of dissolved minerals, which can be deposited on the model surface. I've had this happen, as where I live the water is saturated with calcium ("hard" water). So when I wash the kit parts before assembly (to get rid of any mold release) I then rinse it with distilled water.

You can get 90% isopropyl alcohol online, and most drug stores carry it, but you may have to ask. A little goes a long way.
 
I wash the sprues in dish soap, and rinse and air dry. Just a habit since I had paint adhesion issues decades ago. I haven't had paint sticking problems ever since. So now my terrible paint jobs stay on forever.
 
No washing here including on "old" kits from the 70s and 80s. OTOH: I've thrown away all my MM and other acrylics that would be used for large areas. A lacquer based primer/paint will burn through dang near anything and stick. My only use for acrylics is small hand painted areas of aircraft. I keep a full set of Tamiya acrylics and a few select Vallejo colors for flight suits, marker lights, etc.

MM paints will never again darken my door. Too many super secret additives, mixing, and offerings to the gods to make it "kind of work". I switched to MRP lacquer over Mr Fine Surfacer 1500 a few years ago. Shake, spray, done. I've never had a failure with their product.
 
No washing here including on "old" kits from the 70s and 80s. OTOH: I've thrown away all my MM and other acrylics that would be used for large areas. A lacquer based primer/paint will burn through dang near anything and stick. My only use for acrylics is small hand painted areas of aircraft. I keep a full set of Tamiya acrylics and a few select Vallejo colors for flight suits, marker lights, etc.

MM paints will never again darken my door. Too many super secret additives, mixing, and offerings to the gods to make it "kind of work". I switched to MRP lacquer over Mr Fine Surfacer 1500 a few years ago. Shake, spray, done. I've never had a failure with their product.
I couldn't agree more about MM (Model Mucker) acrylics. As for the rest, I hope you have a good spray booth.
 
I couldn't agree more about MM (Model Mucker) acrylics. As for the rest, I hope you have a good spray booth.
I do. I spent the money to get a Pace booth and have it vented outside. Also, using an airbrush vs rattle can, the quantities of paint/solvents going in the air vs on the model is quite small anyway.
 
I do. I spent the money to get a Pace booth and have it vented outside. Also, using an airbrush vs rattle can, the quantities of paint/solvents going in the air vs on the model is quite small anyway.
Good! That makes me happy. :D While acrylics are generally far safer than enamels or most lacquers, one must also consider the cumulative effects of all the junk and garbage we cannot help but inhale every day. Also, the chemicals in modeling supplies may be legally "safe," but the legal definition of "safe" is not. "Safe" is anything that has not been proven far beyond reasonable doubt to be toxic or carcinogenic. This is very hard to do, since all statistical proofs, properly done, will not result in a 100% result. If the testing resulted in 99% percent toxic, and 1% non-toxic, the material can be labeled and sold as "safe." I once wrote an article for FSM on this subject. Paul Boyer almost didn't accept it because it was so frightening. I also gave a presentation on this to a local IPMS chapter. People turned white. One of the member's wife was there with their newborn. She turned to her husband and said, "You will not touch another model until you have a spray booth."

Carcinogens are like bullets. If one hits you, it's going to be bad. Some are only BBs. Some are 30mm HEAT rounds.

Sorry to be so cheerful, but the topic is one I'm passionate about.
 
Carcinogens are like bullets. If one hits you, it's going to be bad. Some are only BBs. Some are 30mm HEAT rounds.
I have zero medical training, I took High School Biology in about 1979/1980, so much of what we were taught could even have been superseded by now.

But I adhere to a theory that many do, that cancer has more to do with genetics than environment, it is definitely something you can inherit, but even that is no guarantee. I've known people 90+ who smoked multiple packs of cigarettes a day who have no lung cancer while others get it in their 20s or 30s. Again, I'm making generalizations and assumptions with no formal education on the subject. But observation is a core component of the scientific theory. I just spent all of my science credits in college on Astronomy :)

Do not take this to mean that I eschew safety equipment, or in the case of toxic chemicals even basic common sense. Do not play with guns, run with scissors, play golf in a lightning storm, or tempt fate in any way. I wear a real respirator (change the cartridges regularly based on use) and have the garage door open if I am spraying lacquers or enamels, and if the acrylic session will be long I open the door, which sucks in Texas summers.
 
I have zero medical training, I took High School Biology in about 1979/1980, so much of what we were taught could even have been superseded by now.

But I adhere to a theory that many do, that cancer has more to do with genetics than environment, it is definitely something you can inherit, but even that is no guarantee. I've known people 90+ who smoked multiple packs of cigarettes a day who have no lung cancer while others get it in their 20s or 30s. Again, I'm making generalizations and assumptions with no formal education on the subject. But observation is a core component of the scientific theory. I just spent all of my science credits in college on Astronomy :)

Do not take this to mean that I eschew safety equipment, or in the case of toxic chemicals even basic common sense. Do not play with guns, run with scissors, play golf in a lightning storm, or tempt fate in any way. I wear a real respirator (change the cartridges regularly based on use) and have the garage door open if I am spraying lacquers or enamels, and if the acrylic session will be long I open the door, which sucks in Texas summers.
Hence my bullet analogy—don't stand down range. Sad but true: Every day we are bathed in toxic or carcinogenic substances, usually at relatively low concentrations. As for genetics, they do play a role. My father spent most of his adult life working in an environment laden with asbestos particles and smelling of hydrocarbons, including carbon tetrachloride. He also smoked for a time before I was born. No cancer. My mother smoked like a chimney most of her life. No cancer, just emphysema late in life. Yet with that genetic background, I got cancer after lower rates of exposure to carcinogens. I got hit by one of those bullets. Genetics are only one factor, but it also has a lot to do with the variables of exposure, and the strength of the particular carcinogen. Using the example of asbestos, which is a fear buzz word, it's a relatively weak carcinogen. But if it does cause cancer, that particular cancer is particularly nasty. (Sort of sorry about the unintentional pun.)

It's a lot like combat, chances of any one individual getting hit by a bullet are relatively low. But even the most grizzled veterans always keep their heads down.
 
Set up my work area with an under cabinet kitchen fan... I run it just to keep vapors moving outside, and I paint with acrylics by brush.
In my years working in design, I've worked in studios, spray booths, printing houses, silk screen shops and old school photo labs... then bombarded my self in front of CRTs, laser printers and inkjets. I've known guys who literally crawled out of these places on their hands and knees because of carelessness.
My motto is: be safe to the extent you can afford and live some extra quality years enjoying this awesome hobby!
Regarding the initial query, I wash sprues in a small ultrasonic tub, perhaps overkill, but got in the habit in the old days cleaning pen nibs and such.
Just a few drops of detergent does the trick.
 
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