Skip to main content


Showing posts from April, 2009

Keeping Your Compressor Quiet

Air compressors are noisy machines. The two most commonly used ways to quiet them down are to locate the air intake outside (not good for the neighbors) or to build some type of enclosure with sound deadening material inside; that usually causes overheating problems due to poor circulation. The best solution is to construct a silencer that uses the same principles as a gun silencer. But isn't that illegal? Only if you use it on a gun. We're using it on an air compressor. Still, this topic seems to be controversial, mostly by people who have a bury-your-head-in-the-sand approach to security and safety. Here are the materials: Pipe the same size the air compressor port will use, 16"-18" long. Some exhaust pipe, the same length as the other pipe. Some washers you have to make with a hole saw, enough to put one on each end and one every 1-1/2" that will fit around the air compressor intake port pipe and fit inside the exhaust pipe. Steel wool to fit betwe

What Pipe to Use for Your Shop's Compressed Air?

Many people use Schedule 40 PVC pipe and that choice is - OSHA ALERT - potentially dangerous . Under pressure, PVC can explode when it becomes brittle with age or exposure to UV light or when struck by an object. But there are a lot of shops piped with Schedule 40 PVC. If you choose to use it against all advice, at least consider the stronger Schedule 80 pipe and fittings, keep the pipe protected from things that may fall on it and don't hammer near it. PVC is smooth inside which means less pressure drop from friction. There are ABS pipes, Dura-Plus and Chem-Aire , that are rated for compressed gas use . The cost is roughly twice that of Schedule 80 PVC. Dura-Plus comes in a metric size (colored blue) and an industrial size, colored gray; the blue pipe cannot be threaded for standard pipe threads. Chem-Aire pipe is green. Schedule 40 black iron pipe is a popular choice and is very sturdy and durable. It's also heavy and awkward to install and will rust inside, not only a

The Science Behind Piping Your Air Compressor

How many of us have spent hours examining compressor horsepower and CFM ratings, reading shop forum posts and comparing prices to decide what the "perfect" compressor for our shop will be, but then connect a few Harbor Freight air hoses and wonder why the tools don't run well and spit water everywhere? A well-written article at the website delves into the science behind piping your shop's air compressor. In brief, our problems arise because we do not have a properly-sized pipe system to deliver the air to the tool. Compressed air will lose pressure because of the friction from the walls of the pipe. This is expressed in pressure drop per 100 feet of pipe at a particular pressure for a specific diameter of pipe. Of course, designing a proper system is not simple because there are many factors that affect the performance other than pipe size. Another point made in the article is that the velocity of the air through the system is rarely co

Air Polisher by Franz©

While the Franzinator sits between the compressor and the storage tank, the Air Polisher sits, according to Franzinator developer/promoter Franz© , between the air line and the tool you are using. According to him, "The Polisher is really a cheap and dirty copy of a piece of equipment used in the refinery business coupled with a device used in the natural gas delivery business." Here is a crude diagram of the Air Polisher. Examine the diagram for this simple device. The assembly instructions : Remove the valve from an EMPTY 20# propane tank, screw in a pair of 3/4" tees, and a piece of ½" copper tube. The tube can be brazed into a bored-out plug, or if you can't braze, get a 3/4" MPT to ½" copper compression fitting, and bore the shoulder out so you can slide the tube clear through. You'll need a drain fitting for the bottom "tee" so you can drain the accumulated moisture from the tank. You'll also need a suitable fitting for the c

WTF is a Franzinator?

Sometimes the most useful things have the oddest names. Take the Franzinator, for instance. Named after Franz©, its curmudgeonly inventor, the Franzinator is a device used to separate moisture from compressed air. Having moisture in compressed air is not a a good thing, especially in painting where it contaminates the painted surface, or in media blasting where it causes the media to clump and not work as well. As well as causing rust in the air tanks and air tools, moisture is best removed. A number of methods have been developed from expensive refrigerated driers used to pre-condition air before it gets to the compressor, to simple mechanical separators that sit in the air line between the tanks and the air tool. Here is a tank that uses a chemical desiccant to dry the air. There are also ways to install the air lines that are intended to either cause moisture to condense or collect before it is sent to the air tool. A non-mechanical separator causes the moisture in the hotte

Soda Blasting

Soda blasting has many benefits over traditional blasting media in certain circumstances, but the equipment has been expensive prompting many to seek a Do-It-Yourself approach. There's a discussion thread at that looks at the adapter kit offered by Eastwood as well as others . It also provides links to the search engine of the USPTO for soda blasting patents. Here's a soda blasting blog and a site that sells blasters and offers some useful info . The jury is still out, but some knowledgeable input might help. UPDATE A friend had $20,000 in resto work done on her mother's 1954 Desoto Firedome. The work was done by FantomWorks in Norfolk, VA. You may be aware of this shop since they currently have a show on the Velocity cable TV channel. They still show this car in their Completed Projects area, but I'm surprised they do. ( Archived in case they take it down.) Why? They soda-blasted the body to prep it for a complete re-spray and fa