Re: Tamiya primer (was [RealSTMFC] Painting brass)
Back when I had more time than money I built my own spray painting booth. That was over 40 years ago. I took an end from a wooden wire reel abut 24 inches in diameter and cut it in half so I had a semi-circular top and bottom. I made a back from sheet aluminum. The booth is about 2 feet tall because this is how wide the aluminum was. I braced the booth with 1 x 2 sofe pine and installed a bathroom fan in the back. It pulls the air through two 20 x 20 furnace air filters. I hooked a clothes drier hose to the fan outlet and ran it to a dryer outlet. I used to hang the hose out the window when painting, but later replaced a basement window panel with aluminum and an exterior dryer outlet for a permanent and more suitable year round installation. Then I installed a light bulb in the booth and have been using it ever since. I set the booth on an old cabinet the correct height for standing at the booth. The cabinet stores my painting jigs, holders and other painting supplies.
I use a small portable air supply with compressor and air reservoir like you buy at a farm and fleet store. I built a quick disconnect brass manifold out of brass fittings so I can have two airbrushes connected to the compressor at the same time. Of course the manifold is in line after the obligatory water trap and pressure adjustment valve. I wired the paint booth to receive the air compressor electrical chord and work light so that with the flip of one switch the light and fan come on and other controls the air compressor.
All of this is in a small space just off of the laundry room shared by the electric water heater and south staging for the layout.
I used to paint a lot of brass for myself an others. Some manufacturers used a clear coat to protect the brass. Others just painted the model a brass color no doubt to hide some sloppy soldering. As Tim O'Connor suggests, you can soak a lot of this over coating off with lacquer thinner, but it always seemed to require some hand work for a complete job. I soon learned that the overcoats were usually pretty thin and even (Overland Models was great), and it held paint well. I therefore began spraying over the clear coat unless it was exceptionally heavy. I still used gray primer under red and lighter colors. This worked fine when using lacquer based paint like Scalecoat 1.
I invested in a media blasting both for those situations where the clear coat or a failed pant application had to come off. I bought my media blasting booth from a tool catalog; some assembly required. I rigged it up for use with a cheap hobby media blasting airbrush like gun. I have a second air compressor which lives in the garage so I rigged up with quick disconnect fittings so I could use it for other household tasks. The booth lives on a wheeled cart in the garage. I prefer to roll it outside when using it, weather permitting, even when using the booth. Lacquer thinner first and tidy it up with the media blasting. This also etches the surface slightly for paint adherence. I recycle the media by using it over and over. I have not bought any in years. I'm always amazed how you can media blast paint and lettering off of a styrene model, but it has no affect on the details. I've also undone some bad (overdone) weathering with this tool.
I always made sure Mrs. Switzer had a state of the art electric oven in the kitchen. I like freshly baked fruit pies. This is also where I bake on the lacquer based paint applied to brass models. I have my own set of hand-me-down cookie sheets for this process and have to make an appointment to use the oven. Not trusting the thermostat of the oven(s) I pre-heat it to 150 degrees and then shut it off. I then slide brass model on the cookie sheet in the oven and leave it for an hour. The paint dries to a very hard finish. When applying multiple color paint schemes the hard baked finish takes masking well. Just remember, start with light colors and end with dark colors.
I prefer to paint with lacquer based paints and weather with water or alcohol based medial and weathering powders. Remember, one of the best ways to hide a bad paint job is weathering. I've weathered my way out of more than one mess.
Lastly, don't scrimp where it comes to your personal Safety. I have a good quality respirator and use it. Plan B is a particle mask. If you don't believe paint and blasting media can get into your lungs just blow your nose on a white tissue after you are done painting or blasting. What you get will be the color of your project that day.
From: main@RealSTMFC.groups.io [main@RealSTMFC.groups.io] on behalf of Nelson Moyer [npmoyer@...]
Sent: Sunday, April 12, 2020 11:27 AM
Subject: Re: Tamiya primer (was [RealSTMFC] Painting brass)
Yep, mass painting doesn’t work with that paint, though I once primed twelve stock cars in a makeshift cardboard paint booth in the garage. I still prime in the garage, but I do one car at a time using paint handles. I made four handles, so I can do four cars in a session. My paint booth is a fairly small Paasche, and using rattle cans really messes it up due to the wider pattern than an airbrush. Rather than cleaning the paint booth after every rattle car session, I wait for warm, dry day without too much wind (rare in Iowa), open the garage door, and set up a temporary bench of plywood on saw horses, and paint in the garage. Because Tamiya dries so fast, there isn’t any wet overspray except on the plywood, the rest is just powder as you’ve experienced. Of course I use a respirator and gloves, but because the garage door is open, and because Tamiya dries so fast, the fumes are mostly gone after 10-15 minutes.
From: main@RealSTMFC.groups.io [mailto:main@RealSTMFC.groups.io]
On Behalf Of Tim O'Connor