"Painting" - Part 6
Three things to cover this month. We are working on three different cars: our 1951 Packard, 1954 Coupe DeVille and the newly acquired '36 Packard Rumble Seat Coupe. We will cover the coupe later, but I want to say two words that might help anyone welding cast iron manifolds: Powder Weld! The exhaust manifold on the '36 was cracked on the ears in several places. Brass weld held until they were tightened down, then they snapped. Powder welding actually fuses the metal back together giving a solid weld. Then the manifold must be surfaced for a good, flat bond to the block. We will cover more on this later.
On the '54 Cadillac, I mentioned a couple of months back that our car has the original 331 cid engine with the fuel pump on top of the engine. During hot weather the fuel percolates when the engine is shut off. This solved about 80% of our problem. Since then we have sleeved our fuel line with a fantastic product from Kool Mat (216-273-6011). It is a woven sleeve that comes in different sizes from 3/8" to 2" and a choice of plain, red, blue or yellow. We slipped it over our fuel line and it cured our occasional vapor lock problem. They also offer other heat shields, etc. (see press release, front section), with temperature ratings to 1200 F.
Our '51 Packard paint project is moving into its final stages. As discussed in a previous article, we sandblasted, metal prepped, sprayed Ditzler DP-90 epoxy and then K-200 primer. After finishing our bodywork, we are ready for sealer and paint. We are in a new shop that is set up for painting. It is not an expensive paint booth but a 20'x30'x8' area with incandescent ceiling lights and fluorescent wall lights. This light mixture is the closest to natural sunlight. We installed a window over our paint-mixing bench for exact color matching (if such a thing is possible!).
To help insure good paintwork, you will need a good paint gun, good source of filtered, regulated air, and a clean, dust-free painting environment. (In most cases in a garage, you can put up plastic on the ceiling and wet down the walls and floor.). Compressors used for painting should have their tanks drained daily and should have a filter water trap to remove moisture from the lines as well as oil that will contaminate paint. We use a Binks #7 gun with a stock regulator mounted on the gun, setting the pressure at 35 lbs for lacquer (while it lasts!) and 55 at the gun for acrylic enamels. Remember a regulator at the compressor will not give you an accurate reading at the gun because air pressure drops in long hoses. (Touch up guns and air brushes will be covered in future articles.). Low air pressure will cause inadequate atomization of the paint, giving an "orange peel" look. Excessive pressure will cause solvents to evaporate too quickly before the paint hits the surface. Paint mixing is critical. We recommend using a paint shaker to insure a thorough mix. Another tip is to cover your head with a hairnet, wear surgical gloves and paint suit with approved respirator. With base coat, clear coat you will need to check into an air supplied respiratory system. It is important to test your spray pattern by practicing on a piece of paper. Also, follow the paint manufacturer's instructions on thinning and adding hardener. On the final coat, I mix the paint a little thinner than what the instructions call for, giving a smooth surface with a slight texture-a very OEM look that needs very little buffing. See you next month!