All about glue

Glue, unquestionably the most important tool in our building arsenal. Without it there would be no construction in the first place, and with a bad choice in the type you use,  you will be left with a painted pile of parts in a number of years. I have no less than 5-6 different glues in stock at my bench at any given time, and each serves a different purpose depending on what I need to do. Here is a list of the popular types of glue, when you should use them, and why I prefer some over others.

Model Cement: This is the most common general glue you will find. The premise behind cement is that it will actually melt the plastic at the joint ant fuse it together permanently. Cement comes in two forms; a gel like substance in a tube (commonly called "tube glue") and a liquid form that is brushed on. I really like to avoid tube glue to be honest. Tube cement I have found will not weld the parts but rather leaves a skin in between them. This glue ends up deteriorating after some years and this is why if you find a partially assembled build at a swap or garage sale that falls apart easily with a flaky substance near the joints, chances are the builder used tube glue. Liquid cement doesn't deteriorate as tube glue does, but has a longer dry time. This is particularly good if you need to spend alot of time positioning a ill fitting part. Be extra careful to use liquid glue sparingly (don't use the included brush it's too big) as it will attack the plastic creating a large mess if you go overboard. Another note about cement type glues is any plating or paint must be scraped from the joining area. Cement cannot penetrate these surfaces and you will not achieve a true weld if they are not removed.

CA Glue: AKA Superglue or Krazy Glue is my general assembly glue of choice. This has the advantage of being near instant set and can join almost anything. Where cement can only join plastic to plastic, CA can join plastic to wood, metal, resin, vinyl, anything except styrofoam type surfaces, or clear parts as it will eat the former and fog the latter. CA has other useful purposes as well beyond just joining parts. When combined with a "kicker" such as Zip, or Kwik-Set it dries in the blink of an eye and becomes almost as hard if not harder than plastic. When a bead is run over a seam and kicked it provides an instantly dry fill that wont crack or shrink and can be easily sanded. CA comes in a multitude of thicknesses from gel like to water thin and set times from slow to instant depending on what you need to do.

White Glue: Elmer's, Younameit brand school glue, is your basic been using it for arts and crafts since age 4 glue. White glue is water based which means it can be dissolved and cleaned with water and can also be reduced to a thinner viscosity with tap water. This type of glue serves two major purposes in my book: Number one clear parts installation. CA glue will fog these and cement has a high chance to mar them if you slip up. A mistake with Elmer's and a damp Q-Tip will fix it immediately. Number two is interior carpet. Flocking material needs a base to stick to and Elmer's does the trick perfectly. Other glues will dry too fast and the paint methods I have tried isn't sticky enough and leaves bald patches. White glue will stick to most any surface as well which can make it ideal in its diluted state for attaching photo etch latches and emblems to a model car body.

Epoxy: Epoxy standardly comes in a part A and part B bottle. When these are mixed it creates a chemical reaction to create a glue. Epoxies are listed by dry time such as 5 minute Epoxy. 5min epoxy is very good when it comes to areas such as chromed bumpers and door handles on a model car body.

Tenax 7r: Tenax to the best of my knowledge as of 1/2011 was discontinued. Tenax is essentially a intant dry weld similart to plastic cement. The active ingrediant in Tenax is Methylene Chloride which can be obtained from surplus plastic supply houses in one pint cans or larger under the name Caseway SC-125. Be extreemly cautious with these products as there is evidence that they can cause injury or death in these large quantities if not used with care. By care I mean a good ventilation system and preferably a organic vapor respirator. Personally anything I need to use for a hobby that I feel I need a Phd in chemistry to understand isn't worth using. I know alot of builders swear by these pro-weld type industrial glues, to me it's not worth it.