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Building Techniques
Random thoughts by
Ye Olde Materials Engineer - David Rosenberg

Cyanoacrylate (C/Y) adhesive is triggered by moisture! Wood that becomes too dry from being stored too long in low humidity environments (most houses in Rochester in winter) may not have sufficient moisture to activate C/Y glue. Moisten old balsa wood prior to bonding. The wood may have dried out. RTV (Room Temp Vulcanizing)

Silicone rubber adhesive is cured by Acetic Acid (in a molecular sieve). Moisture releases the acetic acid, which cures the rubber. This is called an acetoxy reaction. It is very corrosive to copper wire! Do not use this around electrical connections. A non-corrosive RTV grade is made for electrical insulation. It's cured by alcohol, and is called an alcoxy reaction Radio Shack sells only one type of sealant. It was a sealed tube so I couldn't sniff it. If the sealant smells vinegary it is the acetic acid type. If it smells like alcohol it is the alcoxy type. The Radio Shack product is probably the acetic acid type. They used to carry the non-corrosive type. I checked an old hardened tube- called GE RTV 162 White- Electronic grade. Probably can get it thru a local jobber such as Wolcott Park.

Rubber lubricants - an older type such as Slick (FAI) can be home made. Use 40% tincture of Green Soap to 60% Glycerin (by volume). Heat in a saucepan, for 10 min @ 175F using a meat thermometer. It drives off the alcohol (30% in the soap), till a honey like mix is obtained. Cool and inhale old time memories! It does splash off the rubber, during unwinding, staining the tissue covering. Good for open stick designs, such as Mini-Stick, No- Cal, Science Olympiad or Intermediate stick. Non-splashing types are Son-Of-A-Gun™ Protectorant, (water based silicone), which can be rinsed off for knot re-tying., and Armorall™ (water based Fluorocarbon, such as Teflon), which cannot be rinsed off for knot retying. Both good for tissue covered fuselages, scale, etc.