Woodworker's Journal 2008-32-2, страница 77

Air-transported dust and chips run more efficiently in a straight line than around corners. If ductwork must turn a corner, it's better to use two 45° elbows, rather than a single 90° elbow; the gentler curve allows better airflow.

use, flexible hose extracts a big air resistance penalty in a collection system. A ductwork layout plumbed with smooth-walled pipe will have better airflow (and hence, better collection) than the same layout using only flex hose. Keep flex hose used to connect machines to rigid ductwork short (2¹ to 3') and ground the hose's metal helix wire at both ends. It's better to use metal pipe instead of plastic, because properly grounded metal ductwork won't develop a static charge (common with plastic ductwork) that can give you a nasty shock or even start a shop fire. Make sure all ductwork connections are airtight:

You'd be surprised how a bunch of little leaks can add up and reduce the effectiveness of a collection system. Seal pipe fittings and joints with duct tape (see the photo at right) or silicone caulk. If you've used stove pipe, tape/caulk all joints on adjustable elbows as well as the lengthwise seams on snap-locking straight pipe.

Improve Your Collector

Whether you have a small portable chip collector or a huge centrally installed cyclone system, performance is affected by the same factors. Here are some strategies and modifications to help you get the most out of the collector you already have.

Clean your filters often! When the lower bags in a two- or four-bag chip collector fill up, the unit's filter

inside the bag also forces fine dust particles through the fabric and into the shop air. For best collection and health, empty and clean your filter bags as often as possible. Although they won't fill up, the canister filters used on collectors such as the Delta 50-850A and Oneida XXP020100

area is effectively cut in half. This not only reduces suction significantly, but the higher air pressure

To prevent air leaks that can ruin good collection efficiency, seal all pipe joints with duct tape or silicone caulk.

Wear Respiratory Protection

tven if you have a great dust collection system, there are times you'll need to wear respiratory protection; for example, when running a big belt sander across a panel or sawing up MDF on a table saw, both operations notorious for producing clouds of lung-choking fine dust. But to get the best protection, you must wear the right mask. If you prefer a disposable, make sure it has two straps and Is rated for N95 filtration (the NIOSH standard). Don't cheap out and buy single-strap masks; these are NOT designed to protect you from fine wood dust. Make sure to carefully bend the mask's nose tab so that it fits tightly around your schnoz, and change to a fresh mask whenever the mask gets dirty. If wearing a dust mask fogs up your eyeglasses or protective goggles, switch to a disposable (or half-mask respirator) with a built-in exhaust

valve.The valve's flap allows moist air to escape easily out the bottom of the mask, thus preventing eyewear fogging. Cloth-style face masks, like the "Dust Bee Gone™," are lightweight and offer little air resistance, which adds to user comfort and helps prevent fogging. Washable and reusable, they're also a "greener" alternative to disposable masks.

Step-Up Solution: Powered Respirators

If you have a beard or other facial hair, a regular disposable mask or half-mask respirator won't seal properly around your face, allowing fine dust to creep in. For better protection, switch to a powered air-purifying respirator (PAPR). Devices such as the Trend⁵ Air Shield and Triton air helmet (see photo, right) enclose your entire face or head in a protective bubble that's supplied with clean, filtered air blown in by a

small battery-powered fan. PAPRs are particularly great if you're plagued with allergies and respiratory problems and/or want maximum protection from exotic wood dust and toxic dusts from sanded finishes, glues, etc.

— Sandor Nagyszalanczy

Woodworker's Journal April 2008

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