Wednesday 21 May 2014

Frequently asked questions about Model Building

Welcome to Chinook Hobby Talk Blog! Ready to learn something?

There are so many great books to get started into a hobby or to hone your techniques.

One of our fav's for Car and Truck plastic model building is:


Here are some beginner questions we get asked:

What is a scale model? 
A scale model is a miniature representation of either the real thing or a vehicle from the builder's imagination. Most scale models are made from kits, but some are made from scratch. Modelers strive to build with care so the result looks like the real thing. Careful research from books, photos, and observing the full-size subjects comes into play. Builders try to eliminate seams and create realistic paint jobs, along with adding extra details. 

What is meant by scale?
The scale of a model determines its size in relation to the real thing. A model in 1/25 scale is one twenty-fifth the size of the original. In other words, it would take 25 models end-to-end to span the measurement of the actual subject. 

What is a vacuum-formed kit?
Like an injection-molded kit, these are made from plastic. But vacuum-formed kit parts are heat-pressed into sheets of styrene plastic. Each part must be cut from the sheet, the edges of the parts must be sanded, and a few other special steps must be introduced to the building process to get these kits together. A vacuum-formed kit can be assembled with plastic cements, superglues, or epoxies. They usually are not for beginners, but often may be the only kits available of certain subjects. You should have a couple of years of experience with injection-molded kits before trying one of these. Vacuum-formed kits are generally manufactured and sold by small aftermarket companies. 

What is a resin kit?
Instead of being molded with hot plastic as injection-molded and vacuum-formed kits are, resin kits are made from liquid resins poured into silicone rubber molds. The liquid resin sets after a few minutes, and the molds are separated to release the parts. Resin kits usually are of subjects that are not available in injection-molded kits, and they can be expensive. You must use super glue or epoxy to build resin kits. Like vacuum-formed kits, resin kits are made and sold by aftermarket companies. 

What are photo-etched parts?
These are fine detail parts that usually are obtained as aftermarket items. Parts such as instrument panels, seat buckles, louvers, and grilles, are photographically transferred onto thin sheet metal. Areas outside the images of the parts are etched away in a chemical bath. These add-on parts take some experience to handle and install, but they can improve the look and detail level of a model. 

What kind of cement should I use?
Most plastic kits can be built with tube or liquid-type plastic cements. Superglues (also known as CA for cyanoacrylate) and epoxies also can be used on plastic kits, and will work with other materials such as resin, metal, and wood. 

How can I use superglue on my models?
Superglue can be used to put kits together, and gap-filling superglues (thick formulas) can be used to fill seams and depressions. Cured superglue can be sanded and polished just like plastic. 

Are there kits for people just starting out in modeling?
Yes. Dozens of simple kits have parts that snap together. You won't need glue to assemble them, and you may not need to paint them, either. You can move on to more complex kits after you get your feet wet. 

What kind of paints should I use on a scale model?
Several brands are available, usually in hobby shops. Enamels are oil-based paints and they require paint thinner to thin and clean up. Enamels are easy to apply and come in a wide assortment of colors. Enamels also are available in spray cans, many matching bottled paints in the same line. Water-based acrylic hobby paints are becoming more popular. They are more difficult to airbrush, but they are less toxic than enamels. Most acrylics are thinned and clean up with water. Automotive lacquers, such as touch-up paints, are also used by many builders. Their advantage is they go on thin. These paints require the use of primer, and are very toxic, so a two-stage respirator and sufficient ventilation should be used when spraying them. 

How does a modeler decide which scale to build?
Some modelers prefer to work in one scale only so they can see the size relationship of their subjects. But others may not be concerned with constant scale. If there is only one kit of the subject they are looking for, then that is the model they will build. Usually, large scale models have the best detail, but the variety of subjects is limited. Automobiles usually are found in 1/24 or 1/25 scales. There are some kits in 1/12, 1/16, and 1/20, and 1/43 offers a wide variety of kits and finished models. 

What is stretched sprue?
The material that the parts of a plastic kit are attached to is called sprue. Modelers occasionally use this raw material to produce new parts for their models. For example, by heating the sprue over a candle flame, it can be stretched as thin as hair or bent to produce other shapes. Stretched sprue often is used to represent antennas. 

What are pin marks and mold seams?
During the injection-molding process, certain blemishes appear on the parts. Ejector pins that push the parts from the mold often leave small circular marks on the part. Mold seams sometimes are visible too. They appear as small raised lines along the line where the halves of the mold separate. Modelers try to eliminate these blemishes on their models with filler and sandpaper. 

What is detailing?
Modelers often add details to their models that are not provided in the kits. Some details, such as improved instruments, seats, seat belts, antennas, engine accessories, and decals, are available as aftermarket items, but some modelers make their own improvements. 

Of course there have been many more questions and we are open to answering yours too!  Drop us an email with your questions to hobbywest@shaw.ca and we can help you.

Please feel free to leave comments below!




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