I've been building and flying model rockets since the early 60's. I still have flyable models built in the late 70's and 80's with more the 100flights on each. These are for the most part built "Stock" with White glue, yellow carpenters glue and standard .013" thin walled Craft body tubes. The trick to keeping them flyable is to "Fly the Field" and do the necessary pre-launch preperation including selecting the proper motor matches with the right recovery systems for the field and flying conditions.
One of the very first things I learned is building LIGHT will greatly decrease the chances of Landing damage. The heavier the model the more likely there will be some sort of damage from rough handling, bumpy rides in the car, and of coarse hard landings.
I always have a baggie of various size Chutes and Streamers with snap swivel attachments that allow matching the Expected altitude with the on field weather conditions. One major trick to greatly reduce the chance of Chute Oscillation fin damage is to make all Chutes with a center air spill hole. For most 12" to 24" Plastic or mylar canopies a 3/4" hole is more then sufficent to completely stop chute oscillation.
Always replace the rubber band shockcords supplied by the manfactures as they are always WAY to short. replace them with either 1/8" oval elastic with 70-90lb kevlar shock lines, or for larger models over 1lb use 1/4" elastic with 100-130lb kevlar. The kevlar line need be only the length of the body tube, however I like to use at least 30" if attached around the motor mount with an overhand loop that exits the forward end of the body tube. To make an efficent "anti-zipper" simply attach a 1/2 or 3/4" wide x 3/4" long piece of masking tape doubled over the Kevlar shock line just inside the forward end of the body tube. Over the decades I've leaned the most Standard BT-5 to BT-60 size models can use a maximim of 36" of Kevlar and another 36" to 48" of 1/8" oval elastic to prevent the dreaded "Estes Dent" and help make the Shockcord last a very long time.
Another recovery lesson learned is to NOT attach the chute or streamer to the nosecone, instead attach to the shockcord about 2/3 the distance from the forward end of the Body with a Butterfly knot in the shockcord.
Papering balsa fins does greatly increase the strength without adding a lot of unnecessary weight like epoxy & Fibreglassing does. I like to decrease the thickness of the fin a bit by using about one thickness smaller Basswood. Basswood is a heavier then Balsa and Papered Balsa fins but with it's staight grain and extra strength is easier to finish then balsa. Standard butt on fins are all that is necessary with standard model rockets 1/4A - G motors with decent yellow glue or epoxy fillerts. I have MPR, 5-D12 clustered models that are all constructed with standard Balsa, Basswood, or Clear Polycarbonate fins that are Yellow Glue or Epoxy butt joint attached with 5 or 30minute epoxy fillets that have 50 or more flight without a single fin crack or problem.
Most .013 thin walled Craft tube models can easily last 30-50 flights without any reinforcment but if the model is intended to last a lifetime then adding an internal coupling just ahead of the motor stop will do the trick, absorbing most of the increased heat and after burn from the motors and protecting the area from crimping on landings as the model ages. As mentioned I have and still often fly models that were built in the late 70's and early 80's. that have logged over 100 flights. My original 1970 Saturn-V was retaired in 1999 at fligth 139 (our section number) but is still flyable.
Those are the most important things to making your models last a long time. They will not alway look prestine as when they were first finished but will be quite flight worthy if you follow these fairly easy tricks. Most Important is to always Fly the Field. Which means we really need to know what our models will do on a give motor & recovery system combination
Simulations are our friend but NOT the gospel! simualtions will only be as good as the data put into the program and then should be allowed about 10% lower altitudes.
