|
Surface Preparation |
|
1. |
Roughen surfaces with 150 to 320 (US) grit abrasive. |
|
2. |
Rinse off dust residue. |
|
3. |
Clean with an alkaline cleaning solution or 70% isopropyl
alcohol/water mixture to degrease. |
|
4. |
Rinse in deionized water. |
|
5. |
Dry at 100°C (212°F) for a minimum of one hour. |
|
6. |
Apply adhesive or primer as soon as possible after cleaning. |
| |
|
|
Adhesive Application |
|
1. |
Apply in accordance with manufacturers instructions. Epoxies,
urethanes and cyanoacrylates all perform well. |
|
2. |
Apply uniform pressure until adhesive is set. Apply heat as
required by the adhesive supplier. |
|
3. |
Silane coupling agents can be used as a primer to improve
adhesion if necessary. These are especially beneficial when
bonding in high humidity environments. |
| |
|
|
Joint Design Hints |
|
1. |
Design joints for pure shear with uniform stress distribution
across the joint. Cleavage and peel stresses due to bending
should be avoided. |
|
2. |
Lap Joints |
| |
— Simple lap joints can result in cleavage and peel under
load. |
| |
— Joggle laps improve the stress distribution across the
joint. |
| |
— Double butt lap or double scarf lap joints further improve
resistance to bending. |
|
3. |
Angle Joints |
| |
— Grooved joints (dado joints) offer good resistance to peel
and cleavage. |
| |
— L joints are fair. |
| |
— T joints have good resistance to non-uniform joint stresses. |
|
4. |
Butt Joints |
| |
— Straight butt joints have poor resistance to cleavage and
should be avoided. |
| |
— Tongue and groove or scarfed joints are superior. |
| |
|
