Using specialized finishing techniques
to age and weather your models
By George Riley/photos by the author
Building and finishing a model frequently goes beyond the normal paint and glues that we all use in construction. Capturing the decay and aging of the prototype requires mastering some of the specialized techniques that have been developed specifically to reproduce the aging of wood and oxidation of metals.
To illustrate these techniques I rummaged through some of the many older craftsman kits that have been stored away over the years with the hopes of building them someday. I chose a Keystone Locomotive Works Grasse River Log Buggy kit in O scale for the project. These easily built, old style craftsman kits use precut bass wood, brass wire and die-cast metal detail parts in their construction. The kit is available both in HO and O scale so the techniques used are applicable to any scale that one would choose to work in.
The most important step in craftsman kit construction is the preparation of the various parts prior to assembly. Finishing should be decided upon before any of the pieces are put together. I wanted the completed log buggies to represent rolling stock that had many years of use behind them but were still serviceable. To capture this look the wooden timbers would need to be scored with age and have a gray patina while the metal parts needed to be tarnished and rusted. All of the kit parts would receive the aging process before they were assembled.
Aging the wood
Pre-cut basswood timbers are used for the body of the model. Each pieces had its grain detailed with Micro-Mark’s® Grain Enhancing Tool demonstrated in the first Craftsman Tool Chest installment. Once the wood was distressed, Micro-Mark Age-It EASY was applied with a soft brush and allowed to completely dry. Age-It is a solvent based penetrating stain and weathering solution that will not warp wood and cause the grain to pop like many water based products. Age-It is available in both gray and brown as well as Railroad Tie & Bridge Stain colors leaving the choice of finish up to the modeler.
The dry timbers now have the rich gray patina of weathered lumber. A flat spray is applied to the timbers to seal the wood. Once the flat finish is dry any fuzz is buffed off using 0000 steel wool. The structural beams are now ready to use.
Preparing the Metal Parts
Two techniques are used for the metal parts. For the first, the larger items are degreased, primed and painted dark brown. This provides the base for Micro-Mark’s Rust-n-Dust weathering kit. The second technique uses a chemical blackener to weather the chains, brass wire and a few of the smaller parts. Blacken-It actually sets up a chemical reaction between the metals and solution to tarnish the metal.
Preparing the metal parts for finishing is a very important step. Use files, sand paper and steel wool to clean up the raw castings and parts. Once this step is complete thoroughly degrease and wash all the parts. I have found "Greased Lightning" to be useful for this cleaning since it easily removes any remaining grease and mold release. All parts need to be completely rinsed with clean water then allowed to air dry. A small kitchen strainer is a good tool for holding the parts while being rinsed and dried.
Select the larger casting that will be treated with the Rust-n-Dust and prime the cleaned parts with a thin gray primer and allow them to dry over night. This step will minimize chipping and flaking of the final finish later on. The color over coat is now applied to the primed parts. Use either a dark brown or black. The base color will affect the finished color of the rust. The final step of the painting process is to apply a coat of flat spray lacquer such as Testors Dull Coat. This will rough up the surface and provide more tooth to the finish and give better adherence to the Rust-n-Dust.
Step One: Paint on the terra cotta colored wash and allow to completely dry. A thinner application of this coat is preferable. Once dry each of the parts will have an earth colored patina. I found that the base coat that is used makes a difference in the finished rust color; dark brown will yield a darker, older rust color while a black under coat will give a more orange, newer rust finish.
Step Two: Apply the black wash in the second jar and allow to dry completely. If the wash appears too thin recoat the part until you are satisfied with the results. At this stage each of the parts will have a rich rusty patina.
Step Three: Seal each of the parts with the clear acrylic sealer in the third jar and allow to dry. Once dry the parts are ready to install on the model.
Rust-n-Dust is a water based system that dries quickly and cleans up with water. All of the parts were finished and ready to use in just a few hours. The final step of applying a dust over coat was held off until the model was complete at which time the entire model had dust brushed over it with a soft dry brush.
Blacken-it for Small Parts and Chains
For what ever reason hand rails and pipe details seem to shed paint with infuriating regularity. In addition any one who has ever tried to pain scale sized chain has found that it is akin to pushing a rope. The quick and easy answer to finishing these parts is to use a chemical tarnishing solution. This technique provides a smooth, durable finish that will not hide fine details or chip like paint frequently does.
One thing to keep in mind when using Blacken-It is that it will react differently to different metals. If you are attempting to get a uniform finish it is best to test each of the pieces first. For best results the items to be blackened should be as clean and grease free as possible since Blacken-It will not penetrate dirt and grease.
Once the parts are cleaned and dry the solution is either painted on to each piece or the piece is dipped. Leave Blacken-It on the part until the desired color is attained then wash the item in dish washing detergent and water. Set the parts aside to dry. When completely dry they will be ready to use. One word of caution when using this product is to follow all the safety warnings and instructions. Blacken-It is a reactive agent that should be used as instructed.
Assemble the Buggy
At this point with all of the various parts finished all that is left to do is to assemble the model per the instructions. Older craftsman kits are easy to build due to the advent of modern adhesives. For wood-to-wood construction I use an old standby, Ambroid Liquid Cement. This is a solvent based glue that works well on treated and finished wood. Aliphatic Resin Glues such as Titebond are also useful for wood to wood construction; however, over the long term they are susceptible to moisture.
To attach the metal parts to the wood, Zap Gel was used through out. This product is a thick body ACC glue that allows a bit of working time. To assure that the metal parts would adhere the gluing surfaces were sanded down to bare metal. This removes the paint to which the glue will not readily attach and provides a rough surface on the metal that allows for a better bond.
Once assembly is completed the entire model is given an overall coat of clear flat lacquer. When the flat coat had dried part four of the Rust-n-Dust system was brushed over the log buggy.
One Final Trick
Old rolling stock seems to have clumps of grease on and around the truck journal boxes. This is particularly the case with trucks using friction bearings. To replicate this greasy build up use burnt umber oil paint brushed onto the trucks straight from the tube.
New products and techniques can easily bring older models up to today’s standards so don’t overlook one of those older kits that you have squirreled away for the future.
Old automobiles "come to life" after being treated with a little Rust-n-Dust.
Age It EASY (Item #80873), Rust-n-Dust (Item #84625),
and Blacken-It (Item #60864) are available from Micro-Mark.