Guide to punching Louvers

Punching Louvers... A Guide:

  • No stainless steel.

  • 18 gauge mild steel or less. Aluminum is fine but the corners may tear.

  • Sheet meal must be free of paint, body filler or any undercoating.

  • Area to be punched should be free of dents or wrinkles. Its much easier to repair those prior to punching and besides, they may interfere with the process.

  • Curved panels will limit where you can put louvers. The louver dies need to punch on flat surfaces… tight curves and areas that are not accessible from both sides also limit where louvers can be punched.

  • If you have under hood bracing, it may be in the way. This must be removed and reinstalled after the louvers are punched.

  • If you are concerned with water entering your hood after louvers are punched you can fabricate or make a deflector.

  • Late model sheet metal is thinner and made of a different composition than older fifties era cars. This thin metal may suffer some die damage when stamping. These areas can be touched up with fillers or primer surfacers after punching.

  • The inside edges of the louver opening may need some dressing. This can be done with the use of a small file or heavy grit emery cloth.

  • There are limits to the length of the work-piece. Throat depth on my press is about four feet. In the case of a hood measure from the rear edge of the hood forward… if the distance is no longer than four 48” to where the row of the louvers will start it should work just fine.