I use to paint yachts for a living (also a certified mechanic - but only for gas, not diesel). Also did boats, jet skis, and car work as well, etc... (oh yeah, and my computer has about 300.00 in paint on it - Did it in Dark Blue Imron (for the outside), and Snow White AWL-Grip (for the inside) - Yeah, I know it's overkill. But when you have acces to free paint from a left over job, then it was no big deal.
Hi Ho said:
The clearcoat deteriorated completely, probably because it has never been garaged.
This is usually due to a improperly mixed clearcoat, and or basecoat was allowed to long to dry.
This happens quite a bit on base-coat/Clear-coat paints.
The good thing about base-coat/clear-coat paints, are that they are extremely easy to use (even a novice can't really screw up)
The base coat - goes on like a flat finish, it is fairly hard to get runs/sags in it.
Base-coat dries fairly quick, and will almost be ready for clear-coating within minutes, and is used to bring out the deep(er) shine...
I have an air sprayer and a very large compressor so I am ready to go in that regard.
What kind of sprayer? (Pressure pot system, HVLP, etc..) How large of a tank?(10,20,80 gallon tank)(What is the rated compressor, PSI)
Should I also use a clearcoat?
This will be dependent on the paint you use. Some cheap Nason paint - Or anything that is base-coat/clear-coat. Will need at least 2 coats of clear (IMO)
You may be able to get away with one single semi heavy coat. (Preferred would be a fine mist/tack coat, and a medium coat)
Other paints will not require clearcoat, as most that I use(d) are 5 part paints, that are sprayed in successive coats, and can be wet sanded and buffed with years to come. Example is Imron (polyurethane).. AS well AWL-Grip. However AWL-Grip will be a fairly expensive paint (for use on cars). But it will last the life of the car. It is used on aircraft and marine applications. AWL-Grip does not wet sand and buff well, as a month after, the spot buffed - will dull down. However, it is a very hard paint (epoxy based), and will resist paint chips, as well as (oh say) you are driving behind a dump truck / loaded with pebbles, it will handle much better than almost any other paint to that abuse. (Lastly, AWL-Grip is not a novice paint, and will sag/run/fish eye/gator/etc.. easy if not mixed and sprayed correctly) Please note:: I am not talking about AWL-Grip2. AWL-Grip2 is a easier paint to spray than regular AWL-Grip, and has similar qulaties (strength). It is still a fairly hard to spray type paint for any novice painter. My preference would be AWL-Grip as I have found it a stronger paint.
Do I need to use a primer or can I paint over the old paint after some sanding?
It would be best, as the primer should be based on the paint (chemical type) you are using, as it will bond better. As well, if you plan on changing the color of the car, it will need to be used - Yes even if going from a light color to a dark color. /// Sanding is a must. If there is no body work, then you will only need two grades of paper, I would say use 180 (lower the # the coarser the grit) for the areas with peeling clearcoat, feathering it quite well to where it no longer flakes. Then use at least a 220 grade over the whole car, I use mainly 320 (and it would be preferred as it will shows less sanding scratches).
For clear coat (most paints) will not require sanding in-between. It should be sprayed the same day, as to have a better chemical bond. If by chance you can not spray the clear coat the same day (usually within minutes of base coat) It will need to be lightly scuffed with either 400 grit, or even better a fine (non-coarse) scotch pad. Please know, this will usually still be able to see fine sanding marks if clear-coated next day, or waited to long for the base coat to clear.
Your darker colors will fade quicker than light colors.
This is not true, as silver is the worst at fading.
Regular application of wax, and buffing compound helps a great deal.
This as well is slightly incorrect, as by buffing you will be removing the finish, and it will cause premature paint life, as it will fade quicker (with almost all auto paints, as well a good portion of professional paints.)(it is also not recommended for clear coats) I would only buff out the car, as a last resort, or if I knew exactly what paint was used. Like if Imron was used (and with plenty of coats - say at least 3 coats bare min.) As well, wax is not need for the first year of almost any paint, and AWL-Grip is not recommended for waxing. Waxing will grab-and hold onto dirt, and the car will need frequent washes. AWL-Grip is actually so strong, that (once it is hardened) can be cleaned with lacquer thinner. (Not on AWL-Grip2)Most paint, will almost automatically remove some of the paint - especially if it is still soft - say within 3 months of painting.
(EDIT):: Please note: these are only general guidelines, as there are different chemical paints - I have not even got into Lacquer paints. Also some Imrons (or other polyurethanes) will do well even if clear-coated a week after painted. Clear-coat for Imron is really only needed for any metallic finish. The solid colors would be better if not clear-coated, as they can be buffed up and shined (say, just before the sale of the car) (if a bare min. of 3 coats was used, otherwise - you will get burn-through) If you do plan on clear-coating a week/month/year after, then you will need to wet-sand the car with 1800/2000 grit paper. If done over a week, then even clear-coating will tend to peel within a year. As well, the other sanding papers I mentioned above are in general, as there are usually 3 steps of paper grades. And with any body work, it will be a bare min. 3 steps, and usually 4 or more steps, to remove sanding scratches from the coarser grits. I mean heck, if you have to do any grinding, with say 40 grit, then you will need 100 grit(done fairly heavy, to remove those deep scratches from the 40 or below grit), 120 grit, 180 grit, 220 grit (done heavily), then 320 grit. There is a lot more to it, however, my question would be - Does it need to be perfect? (meaning, not show-car look)-(in this case, I am assuming passable is ok, ------ For a show car look, requires much, much, more work, as the whole car would need to be block-sanded, then guide-coated, then blocked again, as well, it will take a few days of successive base coats then clear-coats, and each of those coats will require sanding in-between coats and will need 24 hours cure time.
(EDIT#2):: Also I forgot to mention, you should scotch pad and comet the car (yes with water as well). Before you start any work, to remove any wax and or road tar and/or grease. Then it does not hurt to do a final scotch pad and comet, to remove any grease from your own finger prints, then blow the car down good - including getting any left over water out of headlights, trim, etc.. Then use a tack cloth for any dust that settles just prior to painting (be careful not to press to hard with a tack-cloth, as it will leave glue spots. The surgeon blue tack cloths are best (IMO) as they only have a light glue tack to them. Also, try not to use any general purpose white tape, due to, if left on to long you will be spending hours removing tape glue. Blue medium tack tapes are best (but are also twice the price). Fair warning - Do not use any oil based cleaners - like mineral spirits, as it will guarantee fish-eyes. Depending on paint used - you can use general purpose lacquer thinner, although the cheap grade is not refined enough for some uses. Better yet, use denatured alcohol. Also use - lint/free rags or paper towels.
