EVERYTHING YOU NEED TO KNOW ABOUT METAL PREP

Must Know Tips When Preparing Your Next Classic Truck Chassis

By Ron Covell – Photography by the Author

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For any project truck, you’ll need to do a lot of sanding and grinding. These processes are so fundamental to metalworking that most people don’t give them a second thought. The more you understand about using these products properly, the more money you can save on materials, with the bonus of getting better results.

02 Both electric and pneumatic die grinders are widely used and each type has its own advantages and disadvantages — Both electric and pneumatic die grinders are widely used, and each type has its own advantages and disadvantages.

The History Of Abrasives

Abrasives have been around for ages–going back to 13^th century China when they actually glued sand onto parchment to make sandpaper. The technology has evolved considerably since then, and the abrasive media used for modern-day cutting, grinding, and smoothing has advanced tremendously.

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03 Pneumatic grinders are very compact and come in a range of sizes and power levels — Pneumatic grinders are very compact and come in a range of sizes and power levels. They do require a good air compressor, which not everyone has.

Power Tool Safety

It’s important to keep safety in mind when using abrasives with power tools. A lot of metal can be removed in a hurry, but it comes off as a shower of hot sparks, and it’s essential to protect your eyes, face, and body from injury. A full-face shield is recommended, along with heavy gloves—and be sure to avoid clothing and footwear made from synthetic materials, which can melt and stick to your skin. Hearing protection is highly recommended too, since a grinder working at full song puts out a lot of noise.

04 Electric grinders are generally very powerful but they tend to be much larger than air tools and the corded varieties keep you tethered to a power outlet — Electric grinders are generally very powerful, but they tend to be much larger than air tools and the corded varieties keep you tethered to a power outlet.

Disc Sander Safety

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There are some additional safety issues to consider, as well. When sanding near an edge, it is important to keep the rotation of the disc oriented so it goes OFF the edge, rather than rotating TOWARD the edge. This strategy will help to prevent the edge of the disc from grabbing the metal edge, which can be very dangerous.

05 There are a lot of good cordless grinders available and while larger than air tools they do not need a power cable — There are a lot of good cordless grinders available, and while larger than air tools they do not need a power cable, which means you can use them anywhere.

Abrasive Cut-Off Wheels

Abrasive cut-off wheels can be used with handheld electric or pneumatic grinders, and they can easily make straight or slightly curved cuts in everything from sheet metal to heavy plate, plus they work well on shapes like rectangular and round tubing and bar, angle iron, and channels. When using a cut-off wheel, it’s important to use a guard that shields the disc, protecting the operator from any flying debris.

06 Proper safety gear is essential when using power abrasives — Proper safety gear is essential when using power abrasives. You will need a face shield, hearing protection, and heavy gloves.

Grinding Discs

Grinding discs are perhaps the most widely used abrasive product, they come in a very broad selection of diameters and grits, and they are engineered for particular applications. While the most common abrasives are designed to work well on mild steel, there are some specialized products that are designed to cope with the particular challenges posed by stainless steel and aluminum.

07 Grinding wheels are ideal for removing a lot of metal in a hurry like large weld beads and parting lines — Grinding wheels are ideal for removing a lot of metal in a hurry, like large weld beads and parting lines on cast or forged components.

How To Grind Welds Smooth

Pay particular attention to the photos that accompany this article, which show how you can smooth a weld—even on thin sheet metal—without reducing the material thickness significantly. The key is to orient the disc so the grains travel along the length of the weld rather than cut across it. As you’ll see, you can make a weld nearly invisible by using the proper techniques, using only a small number of abrasive products.

08 Abrasive cut off wheels are extremely versatile products — Abrasive cut-off wheels are extremely versatile products. They can cut anything from thin sheet metal to heavy plates.

Applying Adequate Abrasive Pressure

Another principle that applies to the whole spectrum of abrasives is to let the tool do the work, without forcing it. When you apply excessive pressure, it generates more heat—and unnecessary heat will cause the abrasive medium to break down much more quickly than necessary.

09 Flap wheels have the ability to blend and smooth large uneven surfaces — Flap wheels have the ability to blend and smooth large uneven surfaces.

It’s also important to change abrasive discs when they start to get dull. Using a badly worn disc can cause excessive heat in the workpiece, which can actually distort thin parts like truck body panels.