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[date: 2014-06-09]
I have never (properly) painted a car before. I'm not afraid of getting my hands dirty, but I started out knowing nothing on this particular topic. So this page documents my learning experience.
I'm always amazed by what other sites and posts (on whatever topic) assume the reader knows.
I also find interesting the range of resources thrown at a task (and the assumptions about what order-of-magnitude commitment people have). There's a large range in painting. Sorry for the non-power-of-10 ranges here, but options really start to open up past $1,000:
As way of calibration, I would label myself as a seriously interested DIY-er, at the $2000 mark and headed higher.
Paint booth:
In my research, some brands pop up repeatedly:
Eastwood is cheaper and is commonly understood to be a rebrand of some other maker. It's easily available but some posts I've read suggest it is good but not great. Since it is a rebrand, the quality may vary over time.
SPI is USA-made and has incredible customer support. SPI doesn't have the product-line breadth of some other makers, but for my purposes the bang-for-buck ratio seems to be high with SPI.
PPG is sometimes (but not always) described as higher quality than even SPI, but far more expensive. This has held me back from experimenting with PPG.
Modern paints are based on isocyanates, especially when hardener is added These are irritants to the eye and respratory tract, and cause cancers. Some bad shit. Some paints do not have isocyanates, but typically they do not dry as hard.
http://en.wikipedia.org/wiki/Isocyanate
Isocyanates pentrate latex. Use nitrile gloves instead. You'll want to fully cover your body. Isocyanates penetrate skin.
Some people use carbon-canister respirators. Questionable. Best to use a supplied-air system. These can be expensive ($700+).
Electrolysis can clean rusted parts. (TODO: I should document my elecdtrolysis setup.) I have found this useful for parts too delicate or intricate to sandblast. Beware that after removing the part from electrolysis, it is prone to rust quickly.
Be sure to completely wash and dry the part after electrolysis.
Rust converters come under many brand names. They convert rust (iron oxide) to a more stable material. In some cases, this may be useful. However, most high quality automotive paints should not be applied over rust converters.
I do not understand the chemical properties of why some paints might not adhere to the results of rust converters, but intutitively, I do not want to paint over converted rust. Rust, iron(III) oxide, takes more space than iron or steel. If the converted surface is not completely impervious to the environment, or if some as-of-yet unreacted elements remain below the surface, it will rust further.
Rust converters may have their uses in the conservation of artifacts stored in a controlled environment. But they seem to be only a temporary patch for in-service metals.
For my purposes, avoid.
However, I have found one product (Evapo-Rust) that seems to cleanly separate existing rust from the bare metal. It doesn't try to convert or hide the rust; it just flakes and cleans it off. I love this stuff. Simple cleanup with water, and even available at Harbor Freight. I keep old coffee cans around (with lids on, because it evaporates) and toss random rusty bolts and things in continually.
Sandblasting deserves its own page, no, its own website.
But the highlights I've learned:
Small parts should be blasted in a blast cabinet. But you'll need proper media and a dust system. A shop-vac with both a bag and filter works, but it will plug up rather quickly.
Big parts could be done outside (if you have no neighbors) or a specially built area. I built an 8x8x8 foot cube out of 2x4s and visqueen for $100. You will still want some sort of negative air pressure (old furnace fan? dust collector?) to keep the dust down inside so you can see while working.
To reuse media, I built a simple cyclone dust collector out of some 5 gallon buckets, sheet metal, and PVC plumbing. I connect it in-line with my shop vac, and vacuum up the area. Reusable blasting media will collect in the bucket; pulverized blasting media and rust will end up in the shop vac.
Paints are very finicky about adhering, especially in the presence of oils or waxes. These must be completely cleaned off the surface.
Epoxy primer