Popular Woodworking 2000-11 № 118, страница 14
to the CFM/PSI feature is choosing a single-stage or two-stage compressor. A single-stage compressor uses one piston to raise the pressure to between 25 and 125psi. In a two-stage compressor, a second piston boosts the pressure to between 100 and 250 psi. Most air tools for woodworking need less than 125 PSI, so a two-stage model may be an expensive upgrade. If you are using a larger compressor to power a connected system in a shop, then a two-stage compressor may make good sense. So before you buy a compressor, check out how much air your tools will gobble up. Then determine what size compressor will provide the needed CFM and check your electrical box. Even the smallest compressors demand 10 to 15 amps to operate, and many larger compressors need 220-volt power to run, pulling 20, and even up to 40 amps to operate. Oilless vs. Oiled Another decision is whether to purchase an oilless or oil-lubricated compressor. Oilless models have a permanent lubricating finish on the moving parts, while others need oil added every so often. Compressors that require oil are quieter, and require minor routine upkeep. Oilless compressors, on the other hand, need less routine maintenance, but you'll have to get them rebuilt after about 1,000 hours of operation. Oil-lubricated machines can go about 2,000 hours before a rebuild. Air Nailers and Staplers Air fastener capacities run the gamut from 23-gauge, 1/2"-long micro pinners to 16d 3V2" framing nailers. Along the way are a wide variety of nailers and staplers ranging in use from trim and upholstery work to commercial cabinetry assembly. For the average home woodworker, two tools will handle almost every application. A brad nailer (firing 18-gauge brads ranging in length from 3/4" to 2") provides adequate fastening power for 90 percent of all woodworking tasks. A headless pinner or a larger 16-gauge finish nailer will likely provide for the other 10 percent. A great deal of commercial furniture is held together by large staples. While they provide better holding power, staples also double the potential for splitting a piece of wood, and they leave a much larger crown visible on the surface of your project. For most home use we don't recommend staplers. Here are some of the features to look for in a brad nailer. Depth of Drive Depth adjustment allows you to vary how deep the fastener will sink into the wood. Optimally, a fastener should sink slightly below the surface, leaving enough of a depression to hold a dab of putty. Some air nailers offer a depth-of-drive adjustment on the tool itself. Some adjust the air flow, while others are mechanical in nature and change the distance of the gun's nose from the workpiece. While the first system is the one we prefer, it also adds to the price. Oiled vs. Oilless Guns Most light-duty fastening tools need a small amount of lubricating oil added to the tool before each use. This keeps the cylinder operating smoothly, but it can cause problems if the exhaust from the tool allows some of the lubricating oil to stain the wood. There are two ways to avoid this problem: higher-priced oilless models (quickly solving the problem), or a directed or directional exhaust port. One Trigger or Two There are two types of safetys on brad nailers: a restrictive nose safety or double-triggers. The restrictive nose mechanism requires the nose safety be depressed against the wood before the trigger can be pulled. A double trigger requires first one, then a second trigger be pulled to fire the gun. As an option to the restrictive nose mechanism, some guns offer bump (or sequential) firing which allows the user to hold the trigger in and fire repeatedly by depressing the nose safety against the material. This option is great for roofing or framing nailers, but isn't a good idea for furniture work. PW PW ODDDDMeDd The following air tools have been tested or used by the editors of Popular Woodworking and have earned their recommendation. Occasional User After much discussion our staff came to the conclusion that the expense involved in buying not only a brad nailer, but the compressor as well keeps most occasional users out of the air tool market. If you're ready to use a brad nailer then class yourself as a serious woodworker and read on. Serious Home Woodworker As an entry level compressor we recommend the Grizzly G8889. For $120 the Grizzly offers a 2hp/12 amp rig with a four-gallon tank that offers 4.2 CFM @ 90PSI. For the woodworker who spends every weekend in the shop a higher capacity compressor is appropriate, and we recommend either the Porter-Cable CPF4515 4.5hp/15gallon compressor for $198, or the Grizzly G8695 2.5hp, 1 Igal-lon compressor for $150.As for brad nailers, there are many brands that would do well in most shops, but we recommend two models over the competition for value and reputation. Porter-Cable's BN200A at $138 and the Accuset A200BN for $129. Advanced Woodworker or Professional For the advanced woodworker we recommend the Porter-Cable CPF2TV3525VP for $389.This two-stage 3.5hp compressor offers a 25 gallon vertical tank, with 5.1CFM at 90 PSA, and a maximum pressure of 175. This is adequate for all brad nailer requirements (and perhaps some roofing) and will even handle some air finishing tasks. For the professional woodworker, we suggest a larger tank compressor with a good value being the Craftsman 16780N,7hp, two-stage, 80 gal. compressor, offering 16.9 CFM at a maximum PSI of 175 for only $899 (not shown on charts). For both advanced hobbiests and professionals we recommend one of two (or both) Senco brad nailers.The SLP 20 ($200) offers 5/s" to 15/s" capacity, while the FinishPro 25 ($200) offers a 5/8 to 21/8" long brad range. |
