Michael Liang 4/13/08
07-12 Woodshop
Woodshop Homework 6
1. What is an adhesive?
An adhesive is basically a substance that is designed to hold materials or objects together by using surface attachment.
2. What are some of the adhesives made of?
Adhesives are made of synthetic materials, cements are usually rubber-based and glues are made with natural materials. All of these are used to bond materials together.
3. What are some characteristics for adhesives, cements, and glues?
Adhesives, cements, and glues must have a setting rate, viscosity, water resistance, flexibility, color, sandability, and gap-filling properties.
4. What are the two basic types of adhesives that is most popular today?
The two basic types of adhesives are thermoplastic adhesives and thermoset adhesives.
5. What are some characteristics of polyvinyl adhesives (PVA)?
Polyvinyl adhesives are very popular for do-it-yourself projects and are also popular in industry. Polyvinyl is set up very rapidly and is frequently called white glue. Polyvinyl film will remain slightly elastic in the joint.
6. What are some facts of Resorcinol-formaldehyde?
Resorcinol-formaldehyde is packaged into two containers and when using it, the powder and liquid catalyst are mixed together. The reason why people use this type of glue is because it is strong, durable, and most importantly, water proof.
7. What is an epoxy and what is its use?
An epoxy is an adhesive and it is used to attach small metal fittings such as hinges, knobs, and brackets to wood surfaces. Epoxy is one of the strongest glue joints, but it is too expensive for large application.
8. What are some facts on casein glue?
Casein glue is packaged in powder and when it is used, the powder is mixed with cold water. Casein glue has little tendency to stain the wood it is applied on.
9. What are some facts on urea-formaldehyde?
Urea-formaldehyde is a resin adhesive and like casein glue, it is packaged as powder and when it is to be used, the powder is mixed with water. It is also less water resistant than polyvinyl.
10. What are some facts on aliphatic thermoplastic resin, hot melts, and alpha cyanacrylate?
Aliphatic thermoplastic resin has a color of yellow and it is somewhat stronger than other polyvinyl resins. Hot melts works very well with glass, certain plastics, metals, and other dense, nonporous materials. Alpha cyanacrylate is used to bond any types of materials and it is sold in solid form.
11. What should you do before applying any kind of glue?
You must always conduct a trial assembly, which is checking to be sure that all of the parts are assembled and that the fit of joints and attachments are well done.
12. What is contact cement and what is mastic?
Contact cement is used to bond plastic laminates and veneer to wood. Mastic is a kind of cement that is used in construction.