Adhesives
Whether during initial construction or repairs after a flight gone wrong, adhesives become a critical part in holding your model aircraft together. Selection of the proper adhesive for a given application will be key in keeping your aircraft in an operable condition without further damaging its construction or weighing the aircraft down too much. This page covers a few different types of adhesives, their pros/cons, and some direction regarding their application. This list is not exhaustive, and a glue may not be the ideal way to “adhere” materials in a given application. Various tapes (e.g., Scotch, duct, electric, packing, fiber), zip ties, string, zippers, and general hardware may be more appropriate and should be given due consideration. Also, there are occasions when you actually don’t want a strong attachment so that the part comes off in a crash instead of snapping.
Use of Adhesives in Lab:
- ALWAYS lay down a gluing mat (sacrificial foam-core board) before using any adhesives or cutting so as to protect the tables beneath
- Secure your project using clamps or using t-pins to hold more delicate pieces in place on the gluing mat while glue sets
- If you must leave the lab while your project is still setting then leave a paper with the following information (templates will be provided in the lab):
- Your name
- Your team name and group affiliation (Team 1 - ME 415)
- When you intend to collect your project (time and date)
- Your phone number in case your project needs to be moved
- Clean up after yourself including spills and proper storage of adhesives
Advice
- Many glues will dissolve foam and some plastics, you should always test on a small sacrificial piece first.
- The weight of glue can add up surprisingly quickly. Overdoing it and having an overly heavy plane is a common beginner mistake.
- Consider how much time you have. You might choose a different adhesive if need to make an in-field repair versus an overnight repair.
Glue options
Listed (roughly) by frequency of use:
Gorilla Glue - 1.138 g/cm3
- Need to get material slightly wet before applying
- Sets in about 30 min. (wait longer for greatest strength)
- Will expand to about three times the size (a little goes a long way)
- Recommended to clamp/secure surfaces while setting
Hot Glue - 0.89 g/cm3
- Bonds with foam and rough surfaces fairly well
- Quick setting time
- Application when the gun is set to a high temperature may melt foam/material
- Glue will melt in heat
- Non-conductive
Epoxy - 1.25 g/cm3
- Comes in pairs of “resin” and “hardener” which will need to be combined
- Combination of resin and hardener is usually 1-to-1, but check packaging
- Usually advertised by setting time (5min, 10min, etc.) but will take longer than advertised for full bonding effect, best to leave overnight
- Sets via an exothermic chemical reaction which WILL melt plastic cups (careful storing leftover mixed glue)
Super Glue - 1.06 g/cm3
- Near instant setting time (unforgiving of mistakes) full strength may take longer
- Can burn or damage skin
- Failure to store properly can lead to ruining of container and wasted glue
Some sources and other resources: