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Archive for June 13th, 2013
The 4-H Car ….Assembly
- Before gluing parts together, always ensure that the contact points are clean and that the parts fit well. When applying the plastic cement, only apply to one of the parts. An excessive amount of plastic cement will not only prolong or prevent proper adhesion, but may also melt and deform the parts. Plastic cement must always be used as conservatively as possible. When gluing clear parts, such as windows or canopies, try to avoid plastic cement. This is because plastic cement can “fog” clear plastic even in areas where not directly applied. For clear parts, use white glue.
- Gaps between parts may become apparent after assembly. To remove a gap that is too large to overlook, it may become necessary to separate the parts, adjust their fit, and re-adhere. Another option is to fill the gap with modeling putty, or another substance which dries to hardness and can be smoothed and painted over. When applying putty, only the smallest amount is required. An excessive amount will be difficult to remove later and in the case of clear parts, may be impossible to remove without evident damage to the part beneath. Follow the instructions on the packaging and use a plastic tool to apply the putty, so as not to scratch the model.
- If an assembled part is not adhering properly in some places, it may not be necessary to separate the parts and re-adhere. Another option is to use a liquid plastic cement to re-adhere the parts. By applying a small amount of liquid glue to the outside of the gap, the glue is drawn into the gap by capillary action. It is important not to apply too much glue, for the reasons above, but also because too much glue may remain outside the gap and dry to hard, malformed bubbles. In general, less than a drop will suffice. When the glue has been applied, hold the parts firmly together until proper adhesion is assured.
Once two parts are glued together, it may be necessary to clamp them together until the glue sets. This may be done by holding the two parts firmly together with your hands, but you may also use a variety of tools to do the same job. Elastic bands, clothespins, plastic clamps, tape, and wire are all suitable materials. When applying the clamps, make sure that the pressure exerted on the parts is great enough to keep the parts together, but not nearly enough to deform or break them. Also make sure that whatever clamp you choose to use will not scratch the plastic.
Whether you are a competitive modeler (contest, 4-H, Boy Scouts, etc…) or building for fun the following links offer some great tips and tricks to help you.
http://www.ndsu.edu/fileadmin/4h/FamilyConsumerScience/FE101.pdf
http://www.scaleautomag.com/
Here we are assembling the engine. He used most of the parts from the Stingaree model, he choose to use use the larger exhaust headers found in the Royal Rail model to customize this model. Here he is trying to hold them in place while they dry.
