Repairing Minor Body Damage - Hammer and Dolly Panel Repair

1.	Hammer and Dolly Panel Repair Diagram

Reforming body contours using hammers and dollies can be done by hand without employing any special equipment, but because it requires high expertise, the quality of the work depends on the technician’s workmanship.
With hammers and dollies, it is extremely difficult to finish the repair work to the same level of its undamaged pressed part.
So, parts replacement may be necessary, depending on the level of the damage. Collision repairs require a variety of handwork that is not difficult individually. If the damaged areas can be easily accessed, hammer and dolly use is recommended because it can be done easily and in a short time.

2.	Repair Steps

Confirm damaged area:

Before starting the repair work, make sure to confirm the deformation of the damaged area.

Use visual and feel inspection methods for minor body damage.

Some obvious damage only requires a visual inspection. Other damage is more difficult to spot and requires projected light to identify damage by reflection. For these types of damage, it is important to check the damaged areas from multiple angles.

Gently touch the damaged areas with your hands to judge the damage by feel. Wear cloth gloves or put a thin cloth between the surface and hand when touching to improve the sensitivity. Move your hands in many directions for an accurate inspection.

(Reference)

Bent or swelled installed parts, such as a front fender, may sometimes be returned back to the original shape by removing their installation fasteners (bolts).

Remove foreign materials adhered to the backside of the panel Remove all the foreign materials such as undercoat, sealer, and clay adhered to the rear surface with a scraper etc. so that the dolly or spoon can directly contact the actual steel back surface.

Rough panel correction
Pull-out the damaged area using a body puller.
Using the body puller with a variety of attachments, a variety of parts can be pulled-out.

Select hammers, dollies or spoons:

Select the most appropriate hammers, dollies, and spoons to the curves on the repaired panel.

If the curves of the damaged part of the panel do not perfectly fit to any of those of the dollies or spoons available, select dollies or spoons of which curves are smaller than those of the panel damaged area.

Make the surface of hammers, dollies and spoons are smooth so they don’t cause any damage or scratching of the repaired surface.

Hand contour repair using a hammer

3.	Hammer Technique

Hammer Technique:

Lightly hold the hammer near the end of the handle and swing it using your wrist.

When striking with a hammer, the hammer face must always make flat and even contact with the panel surface.

When striking with a hammer, the hammer face must always make flat and even contact with the panel surface. If the edge of the hammer face contacts the surface, a crescent shaped mark or dent will be left on the panel that is very difficult to remove. Do not use too much force. Strike the panel as if you were bouncing the hammer. If the panel is struck with too much force, it will be elongated and require shrinking (drawing) work later.

4.	Hammering Off Dolly and Hammering On Dolly

Hammer off dolly

Hammering off dolly is used to correct comparatively large unevenness. The recess is stricken out with a dolly. Hold the dolly right beneath the depressed area and strike the raised areas around it using the hammer.
The raised areas will be gradually lowered by the hammer impact and the depressed area will be raised by the dolly contact, due to the reaction of the hammer impact.
It is very important to maintain a good balance between the hammer impact and holding force to keep the dolly in position.

Hammer on dolly

Hammering on the dolly is used to correct small raised areas on the repair surface.
Place the dolly directly under the raised area and strike the area from above with a hammer. While the hammer impact is flattening the raised area, the dolly rebounds due to the hammer impact. To completely flatten the area, repeat this work along the repaired panel surface while moving the hammer and dolly.

5.	Using a Body Spoon (Example)

While pushing against the inside of the panel using a spoon, strike the outside of the panel with a hammer. Use this technique for difficult to access areas such as door panels, rear wheelhouse, etc.

6.	Deep Dents

Correct the depressed area of the part using a dolly from inside.

Flatten by alternately repeating hammer off dolly and on dolly techniques.

7.	Continuous Small Deformation

Press the dolly against the rear of the depressed area and strike the raise area from above with a hammer.

Repeat the step above while moving the hammer and dolly together along the panel surface, repeat the work.

8.	Partial Plastic Deformation

9.	Deformation at Corner

Flat strike the uneven or depressed area with a dolly bring the surface back towards its original shape.

A way to repair dents on a sharply curved area. Alternate using the hammer and dolly.