Submitted by
Categories: [Finishing]
Note: Added by the webmaster from notes on a presentation given by HRSMS member Jack Bobbitt
Surface Preparation
It is vitally important to start with a well-prepared surface.
Fill in wood grain and minor imperfections to a degree appropriate for the scale of the model. Artists gesso is recommended for this use. Brush on and sand about three times. Shellac thinned with two parts alcohol can also be used for this purpose. Do not use polyurethanes or varnishes. The paint will shift and crack. In addition, the use of synthetic materials is highly discouraged due to known problems (or unknown results) with aging.
Fill larger imperfections with automotive repair compound (such as Bondo) or glazing and spotting putty.
Masking
Use a good-quality light-hold tape, so that prior finishes are not destroyed when the tape is removed. 3M Fine Line Tape 218 and 3M Vinyl Tape 471 (comes in 9 colors, blue perhaps being most common) are recommended. Burnish the edges so that paint does not run under the tape. Another known practice is to spray the edge of the tape with clear lacquer prior to applying the paint. The lacquer seals the tape edge and prevents paint from running under. Automotive stores carry a wide range of high-quality masking products.
Paints
If you're concerned about archival properties - the first word from Jack is "NO ACRYLICS!!" It should be considered noteworthy that the Smithsonian Institute (Smithsonian, Vol.23, No.10, January 1993) has expressed strong concerns over the longevity of these and other synthetic materials. Jack recommends any of the following:
- Japan colors (must be thinned with turpentine)
- Floquil
- Model Masters (includes a rust color Jack uses for weathering)
Constantine's is one source for the Japan Colors. You can find their contact information on our resources page by selecting "finishes". At the time of writing the Japan Colors were found under the "Wood Stains" category of their website.
Jack has also discovered, through a fellow modeller, that Color Place - Red Oxide Primer (found at Walmart) is an excellent representation of red anti-fouling. In fact, he reports it is the best he has ever seen.
Mixing and thinning paints
Use mineral spirits for thinning paint. Acetone can be used for thinning epoxy.
Use an artist color wheel as a guide when mixing paints to achieve the desired color. Measure carefully and take good notes so that you will be able to reproduce the color.
Natural finishes
Watco (Danish) Oil is the product of choice. It is a penetrating oil that protects the wood from within. It does not leave a sticky coating on the surface and will not attract or collect dust. It is quick drying and usually takes only 1 or 2 coats. No other coatings need to be applied over it. Jack reports that he has seen applications of Watco Oil that still look good-as-new after 20 years.
When clear oil is applied to cherry (don't use the stained oil unless you're trying to achieve a particular color) it makes an excellent representation of mahogany.
Brushes
- Golden Taklon is an excellent sythetic alternative to the much more costly sable brushes.
- Brush sizes go down to 10/2.
- Blick is one recommended manufacturer of brushes.
- Start from center and brush toward edge. In the opposite direction the paint will be scraped off by, and build up on, the edge.
- Do no wash with hot water. This will only speed the drying/setting of the paint in the brush.
- Faux Meister's Brush Soap and Conditioner is recommended for restoring brushes.
- Don't keep brushes that are worn or will no longer hold their shape. The minor savings is not worth affect on the model, which in the end is worth a lot more due to all of your labors.