Replace door skins.

Lesson Plan for

CRT 130-1

NON-STRUCTURAL ANALYSIS AND DAMAGE REPAIR SECTION I

Course HS Title: / Non-Structural Analysis and Damage Repair / Program:
KCTCS Courses included in HS Title: (Lesson is prepared for course highlighted.)
KCTCS Course No. / KCTCS Course Title
Introduction/Context / This lesson will instruct the student on how to replace door skins. Knowledge of these techniques and the skills required to correct problems associated with this task are necessary for a student to acquire if they wish to compete for high paying, high skilled jobs in an Automotive Repair Facility. Entry level technicians need to be able to perform this task to 100% accuracy. Incorrectly performing this task can lead to an automobile accident or create customer satisfaction issues.
Prepared By / School / Date:
Grade Level / No. Students / No.IEP's: / Lesson Length:
Task
Replace door skins.
No. / Objective
1 / Given the proper tools and instruction, the student will be able to replace door skins, and pass a written test covering the task with 100% accuracy.

Connections:

New Common Core:
RST 11-12-2
RST 11-12-3
New Common Core Technical
TD-SYS-1
TD-OPS-3
New Science Standards
HS-PS2-3.
Skills Standards:
AA001
EG011

INSTRUCTIONAL MATERIALS/TECHNOLOGY

Teacher Designed Materials and Other Handouts


Textbooks and Workbooks

Author / Title/ISBN No. / Edition / Publisher / Pages
Various / ASE Test Prep Non Structural Analysis and Damage Repair / Third / Delmar / 23-24
Tobaldt/Richardson / Auto Body Repairing and Refinishing / 2000 / Goodheart/Wilcox / 148


Equipment

Quantity / Item / Source
As Needed / Welder / Various
As Needed / Adhesive / Various


Content/Presentation/Demonstration Outline

Tell students that like other damaged panels, a door skin can be bumped back into shape, pulled into shape, or replaced. Inform them that the decision is based on the amount of door frame damage. Another option is replacement of just the door skin. Explain that the door skin wraps around and is flanged around the door frame, and that the door skin is secured to the frame either by welding or with adhesives. Let them know that a welded skin has spot welds that hold the skin onto its frame, and an adhesive door skin is bonded—not welded—to the door frame, and requires different replacement methods. Tell them that to replace a door skin, they should follow the manufacturer’s recommended procedures.
Teach students that all the doors of unibody vehicles have inner metal reinforcements at various locations. There are also some other door frame reinforcements, such as at the hinge locations at the door lock plate. Explain that door intrusion beams, normally used inside side doors, are welded or bolted to the metal support brackets on the door frame to increase door strength. Let them know that anti-intrusion beams are located inside the door on passenger cars. If the high-strength steel part is damaged, tell them that either the beam or door shell should be replaced and not repaired.
To replace a door skin, instruct students to remove the door from the vehicle and take off the exterior moldings and hardware. It is generally not necessary to remove the window regulator, remote control mechanism, lock mechanism, or window runs. Tell them to place the door on a flat surface so that the bottom edge of the door extends over the edge of the surface. They should then remove the hem flange with a grinder and remove the damaged door skin. If necessary, have them repair any damage to the inner panel. Before installing the new door skin, instruct them to apply sealers and sound deadeners to the back of the panel. This is because the internal door mechanisms may obstruct portions of the replacement panel after the skin is installed.
On adhesive-bonded door skins, tell students that strong, two-part polyurethane adhesive is used to secure the skin. They should clean and prime the hem flange and the inner flange before installing the skin. Instruct them to correctly position the new skin over the door frame and apply the adhesive to the flanges. They should then bend the hem flange over the inner panel flange with a hammer and a dolly. This will create a hem seam. Let them know that a special pneumatic hemming tool can also be used to create the seam. Tell them to use extreme care to prevent deforming the new skin when making the hem seam.
Instruct students that the procedure for replacing welded door skins is similar to the procedure for replacing adhesive-bonded skins. After removing the damaged door skin, tell students to apply weld-through primer to the flange area. They should then replace sound deadener pads (silencers) and apply sealer to the back of the new skin. Tell them to carefully align the skin and clamp it in position, then bend the hem flange over the inner flange. After bending, let them know that the hem seam can be spot welded or plug welded. Tell them to make certain that the welds penetrate to the inner panel or frame of the door. After installing the new skin, they should prime and paint the exterior surface of the panel and attach all trim and hardware.


Applications/Practice

1 / Refer to content


Evaluation and feedback Prior to Testing or Lab Work

1 / Objective 1. / Formative assessment / Instructor will observe students as they practice the procedure to assure correct procedure and safety practices are being followed. A checklist will be utilized to chart student progress on the task. Questioning techniques will be utilized as necessary to demonstrate student comprehension / Adaptations and/or accommodations for special needs students will be added if required.


STUDENT ASSESSMENT:(Assess student progress with performance criteria.)

1 / Objective 1 / Summative assessment / written test questions on stated objective / adaptation and / or accommodations for special needs students will be added if required
IMPACT--Reflection/Analysis of Teaching and Learning: (How did students’ progress in relation to the state objectives? Was the instruction successful? Analyze samples of student work particularly that which is unsatisfactory, for the purpose of planning further instruction.)
REFINEMENT--Lesson Extension and Follow-up: (To be filled in as the lesson is modified during initial planning and/or during the teaching learning process.)