Why Sheet Metal Warps

Sheet metal makes it impossible for rats and squirrels to climb trees as its smooth surface doesn t offer the same purchase that tree trunks do.

Why sheet metal warps. The bottom will expand slightly more than the raised lip. The 6 most common causes. When the weld shrinks along its length it causes base metal to twist around the weld figure 3. As they heat up they don t all expand at the same rate.

These all have a high surface area to mass and will expand quite a lot at galvanizing temperature. If these materials are done in loose sheets their expansion and contraction will go unnoticed. But if you buy good quality pans and use them properly you ll never have to worry about warping. As i explained upfront the molecular structure of pans is altered when they become exposed to rapid changes in temperature energy which causes uneven expansion and contraction.

You can tell your metal cookie sheet is under stress when you hear it popping and crackling in the oven. If you re welding thinner materials like automotive sheet metal it is more critical that you keep the heat to a minimum when welding. This creates stress at the folded edges. Design and welding should be addressed to minimize this sort of warping.

Warped metal when welding is a constant struggle we all deal with regardless of thickness of the material. Steel being galvanized progresses through a temperature cycle upon immersion into and withdrawal from the galvanizing bath. When i experimented sandblasting etched designs into plexi glass plastic acrylic glass with aluminum oxide abrasive i noticed it actually start to melt the plastic. The most common type of heat related warpage is with solid sheet material perforated plate wire mesh and expanded metal.

There are a few ways we ve found that help with this process and we decided to list them below. Sheet metal warping because of heat peening of sandblast abrasive in my honest opinion sheet metal may warp when sandblasting due to a little bit of both reasons. There are internal stresses in the steel often from welding or cold working as an example an i beam or c channel is usually hot worked but some cold work can happen so they can sometimes. If the pan or sheet is too thin the stress may cause it to buckle or twist.

Use a strip of sheet metal 18 to 24 inches wide.