posted 08-20-2009 11:44 PM               

I have a few plastic pieces that have broken off my lunar modules (i.e., Franklin Mint and Danbury Mint models). For items like antennas which easily break off and don't have much surface area for gluing (like the end of a narrow support strut) is there a preferred method for secure repair? I have had some success with using a single tiny drop of crazy glue, but sometimes that is very difficult due to the nature of the limited contact surface (almost like trying to glue the end of a tooth pick to something). I guess I have two basic questions:

1. What type of glue is recommended for this type of repair assuming the two parts are plastic (crazy glue, testers model glue, or ???)
   
2. What is the best technique for making the repair? Any special tips for how to go about gluing them back together? I find the hardest part is holding the pieces still while the glue dries.

When a part breaks off I try to match it up in the correct orientation and alignment to get a secure fit but that's pretty hard to do hard to do so I have also considered gently sanding the surfaces flat for better contact but am reluctant to alter the pieces too much.

Once the joint is repaired I assume some touch up might be recommended at the joint area, but just getting a solid/secure joint would make me very pleased.

posted 08-21-2009 12:55 PM               

Biggest concern with CA type glues (Cyano Acrylate, aka Super glue) is they tend to get brittle and have their best bonding in one direction (the gluing direction). Give the part a good side knock and it can break the bond. But there are rubber toughened CA glues available now that have a little bit of rubber in them to help the joint to flex slightly. These might work well. You can usually find them at most decent hobby shops that stock supplies for modelers and RC aircraft fliers. Bob Smith Industries makes three varieties of rubber toughened CA, one is black in color and the other two are clear. The black works well and so does the pink label stuff (clear gap filling flexible, part # BSI120). BSI glues or equivalent brands can be found in many hobby shops and they usually have the address of the store printed right on the bottle.

Another advantage of this stuff over Krazy Glue is it tends to produce stronger bonds. Reason being is over the counter Super Glue and Krazy glue has preservatives in it to give it longer shelf life. Hobby glues do not (hence they only last six months once opened), but they do bond better.