Partnering with a punch and flange tool

 

Greg Davie takes a look at the punch and flange tool, often overlooked in the workshop, but still a useful partner in the repair process.

Although a punch and flange tool is not something that you are likely to use on a daily basis, it’s an invaluable piece of equipment which enables professional repairs of damaged or rusted panels. Although these types of tools have been around for some time, the general industry does not appear to be widely knowledgeable of their benefits.

Punch and flange tools conduct two operations. The flange component profiles the metal while the punch creates holes around the edge of the replacement sheet, allowing for clean MIG welding.

When to use:

While the majority of panel work today is replace rather than repair, there are times when replacement is not an option; this particularly stands true for restoration work. If you come across rusted sections, or damage in the middle of a panel, cutting away the affected area and welding a new segment is a stronger and less labour-intensive option then replacing the entire skin or using excessive fill.

How It works

The process is straight forward. When attempting a repair of this type it is best to remove the damaged area in the shape of a circle or oval because it is difficult to profile corners.

Step 1

Draw a circle or oval around the affected area allowing enough clean panel space to create a profile.

Step 2

Drill a hole inside of the drawn circle that is big enough to insert a nibbler head. Proceed to cut away the damaged section.

**TIP – Due to its distortion-free cutting ability, it is recommended that you use a nibbler to cut away the damaged section.

Step 3

Using the flange head attachment, create a clean profile around the circumference of the cut circle overlapping each action by approximately one-quarter of the head size.

Step 4

Create a template of the repair area using stiff cardboard, ensuing it sits well within the profile. Use this template to produce an accurate infill from new sheet metal.

Step 5

Using the punch head attachment, create a series of holes around the newly created replacement panel, allowing approximately 25 mm between holes.
NOTE – Only create holes on the replacement section, do not create holes in the profiled

panel.

Step 6

Lay the new replacement panel into the flange profile. Proceed to lightly MIG weld in each of the holes.

TIP – When welding, firmly hold the new panel in place to keep it flush. After welding the first hole, move on to the opposite side. The order of welding should be 12 o’clock, 6 o’clock, 9 o’clock, 3 o’clock, working your way around until all holes have been filled. This will ensure you do not create too much heat in the panel which can cause distortion.

Step 7

Clean up by grinding back weld residue, lightly fill, sand and prepare for paint.
The more you use the process the more comfortable and efficient you will be with it. There are a number of the air tool brands in the market that carry a punch and flange tool in their range and it is worthwhile researching the features and benefits of each. If you would like to see a punch and flange tool in action, go to You Tube and search for Punch and Flange Tool.

Tech Tips is researched and written by Greg Davie of GnG Sales, suppliers of smash repairequipment and consumables under the brand names: Mako, Supes, Star Sprayguns, Star New Century, Workquip Autoglym and Tranmax. Head Office: 3 Foundry Road, Seven Hills, NSW 2147. Tel: (02) 9680 4464.