The Modding Toolbox: Abrasives Part One - Hand Tools

Written by Alex Banks

March 20, 2018 | 19:00

Tags: #case-modding #cutting #sanding #sandpaper #toolbox

With hand files out of the way, let's move onto the backbone of sanding: papers and cloths.

Most of us have these lying around from odd jobs around the house. I would suggest picking up a collection of useful papers that span a number of grits and then keep them organised in a divider folder. Being organised really helps here, as frankly it's frustrating beyond measure when you're either frantically searching for the last piece of a given grit or find out mid-project that you're missing the type you need.

Working out which papers you need will largely depend on the sort of materials you usually work with. I tend to work with metals and plastics, so I have a decent collection of abrasive pads, discs, and sheets designed for use with those, such as silicon carbide wet and dry paper or emery cloths. It's a good idea to have a steady progression in grit numbers for the papers, because if you want to be able to leave a flawless, smooth finish on almost any surface you'll need to work through the grits, getting progressively finer. These are the ones I use at home and would suggest as a good starting point. The higher the grit number, the finer the abrasive.

  • 80 grit
  • 120 grit
  • 180 grit
  • 320 grit
  • 500 grit
  • 800 grit
  • 1,000 grit
  • 2,000 grit
  • 3,000 grit

Looking at the above values, 80-180 grit would be for the rough work, 320-500 for medium, and 800+ for fine smoothing (often for polishing). The packs you find at the hardware store will frequently be more liberal with that definition, as they're for general DIY use; I've seen some call 240 very fine, and many don't top out at the high numbers either. If you're sanding aluminium or paintwork, you'll quickly notice that unless you use the very high grit numbers you'll end up with an uneven finish.

Which Type to Buy and Where?

We touched on this above that you want to choose the abrasives to match the materials and intended finishes you're working with. Here's a brief overview of the types of abrasive sheets and rolls available:

  • Glass Paper - As the name suggests this paper is sand paper in the classic form. Generally it only comes in the coarser grits and is suitable primarily for working with wood. This is a dry sanding material since manufacturers will rarely use a waterproof glue here, but if working with wood that won't matter at all.
  • Aluminium Oxide Paper/Cloth - Aluminium oxide (aka corundum, ruby, and sapphire when naturally occurring) is a stronger material than glass and is suitable for use with a wide range of materials, including both wood and metals. Aluminium oxide abrasives conveniently also come with a variety of backing choices, including different papers and cloths (emery cloth is usually aluminium oxide) which can make it quite versatile. Depending on the adhesive used, some are also suitable for wet sanding, which can be very useful for metal and plastic work. Cloth backings are more durable than the paper ones and can be really handy for more intense jobs that may wear through a paper backing.
  • Silicon Carbide Paper/Cloth - This is the typical dark coating you'll find on 'Wet and Dry' papers. Silicon carbide is available in a huge number of grits, ranging from the low 100s through to 3,000+. Paired with waterproof adhesives and backings, it makes for a good choice for fine sanding work. Being able to lubricate the abrasives with water or mineral oil helps to achieve a very smooth finish on metals and plastics - essential if you're trying to achieve an even paint finish or a mirror polish.
  • Steel wool - Not a paper/cloth but very much a useful abrasive material. The fine wool is great for leaving a satin finish in both metals and plastics.

As to where to buy, while you'll often find a good selection in hardware stores, I like to shop at automotive paintwork suppliers online. They're specialists in sanding to a very fine finish, so they usually stock a wide range of materials that can help you along the way. Even Halfords (if you're UK-based) has a decent selection, although don't expect much from those papers, as they tend to fall apart. More general shops like Amazon are also good if you type in exactly what you're looking for, but it's hard to browse since there are so many overlapping product descriptions.

An interesting option is to buy papers that are designed for use with power tools, since they usually rock a much stronger adhesive. We'll be covering power sanding tools in a later instalment, but look to the major brands to see what they offer for these. I use Festool pads, as although they're rather pricey, they last for ages and consistently leave a wonderful finish.

Hand Sanding Aides

Sanding by hand can be quite a laborious process, so thankfully there are a few handy bits of kit that can help you out. These mostly come in the form of sanding blocks and 'hand sanders', both of which serve largely the same purpose.

One of the important things both of these devices help with is providing a flat, solid backing for the paper. Trying to sand completely by hand doesn't always work so well as our hands are generally quite soft. This means when sanding the edges of panels, you may notice that it won't sand evenly, leaving a bowed surface. Sometimes this is quite a nice look, but other times it's not desirable, such as when making panels that need to fit flush against one another. Using a hard base helps to control this and prevents the paper from flexing as much.

Hand sanders are a very simple approach to this; the paper just clips in on either end. You'll have to trim it to size, but generally they're rather practical. I like using mine for brushed finishes; it's quite easy to maintain a consistent grain thanks to the handle.

Going even simpler, we have a cork sanding block. It's the same deal but a bit more basic. These are handy to have, though, as you can use different sides for alternative grips and holds. Emery blocks are a bit like a hybrid where the block itself is the abrasive.

Emery boards are essentially like large nail files. These are flat surfaces with an emery cloth bonded to them. They can be very useful when working with small items like screws or small mounts that you may want to have flat, flush edges on. They're also very easy to make at home; you need only glue some emery paper to a flat piece of wood.

With the basics of hand tools covered, join us for Part Two next time where I'll be going through power tools. Do chime in with your own experiences too!

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