Question: A friend of mind had his wings break in half during flight. I don't want this to happen to me. How do I make sure that I do a good job when joining the wing halves of my ARF?

Answer: Use 30 Minute Epoxy and don't overpower your model.

Better Answer: Wing strength is critical to the integrity of an aircraft and we do extensive testing to make sure that the design is strong and solid. Wing failure is not something that we see or hear a lot of . We have analysed a few wing failures  sent to us for review by consumers and in all cases we found that improper assembly and use of adhesives was the cause of the failure. Do a dry assembly first with no adhesive while following the procedures listed in the instruction manual. This will ensure that the parts fit well and that you are familiar with what goes where and how to install it. When you are ready for the final assembly with adhesive, use 30 Minute Epoxy only and use plenty of it. Secondly do not overpower your model. See below for some more information that you may find helpful.

Question: Epoxy is available in different cure speeds. Should I use a Slow Cure (30 Minute) or a Fast Cure (5 Minute) Epoxy?

Short Answer: Use 30 Minute Epoxy where strength and structural integrity is important such as when joining wings or mounting stabilizers, engine firewalls etc. Use Fast Cure for quick repairs of small non-critical components or joints. If in doubt, always use 30 Minute Epoxy.

Better Answer: There are two general factors to consider,  Bond Strength and Working Time. 30 Minute Epoxy creates a stronger bond and it gives you more time to work. 5 Minute Epoxy gives a good bond but it is not as strong as 30 Minute Epoxy and it must be used very quickly, particulary in warm conditions.

The Bond Strength is pretty straighforward... 30 Minute simply gives stronger bonds. Use 30 Minute when joining wings, installing stabilizers, engine firewalls or other load bearing critical structural components that you simply cannot afford to have come off or fail. Use 5 Minute Epoxy for quick minor repairs of non-load bearing or light load bearing less critical components.

The Working Time is something that modelers frequently overlook and tend to err a bit in favor of  "fast is good". In some cases, like a quick repair of a simple small component... fast is really nice! But in cases where the amount of adhesive is considerable, the components are large or complex and/or need to be simultaneously mated with other parts.... you need to allow for plenty of time to work in order to get the parts aligned and properly placed. It is very important that the Epoxy is fully "wet" when being used. If Epoxy starts to thicken at all before the parts are joined, the Epoxy will not produce a good bond.

The worst possible scenario is using 5 Minute Epoxy on a complex multi-piece job like joining a wing. We have had too many calls from people who end up with the Epoxy beginning to cure before the wing halves are properly joined. We have also seen wing joints after in flight failures caused by gummy thick half cured Epoxy not penetrating and filling the joint and component substrates properly.

If you have any doubts about the complexity of a job, need for strength, working time etc, always use 30 Minute Epoxy!

Question: How much engine power is appropriate? Many models give a range of engine sizes... should I use an engine that is at the bottom of the range or go for broke and use the biggest engine recommended?

Answer: If in doubt go with something that is more or less in the middle of the range unless the distributor or your dealer have some specific recommendations.

DO NOT use an engine larger than the maximum size recommended by the model manufacturer. You run the risk of overstressing the airframe which can lead to sudden breakup of the model in the air and may injure someone.

Better Answer: Generally manufacturers specify a range of engine sizes for a model. An engine in the middle usually works well but you might want to consider going with the higher end of the range if you are going to be flying at altitudes above 2000 feet or in very hot weather or flying off of floats. Naturally if you are doing all of these, flying at high altitudes from a lake on a hot day... the bigger engine is the better choice. You might also want to ask around in your area to see what other RC flyers are doing. Be a bit cautious of the "power at all costs" type of recommendations but listen carefully when you get advice from those who have thought it through and tried it out.