Air Equipment
Healey Journal
Air Equipment provides some of the most versatile and effective tools a mechanic can use. An overview of them is shown below:
The most important element in any system is the air compressor- it powers everything else and your ability to work will be helped or hindered by it. When its good, it will be taken for granted, and when its not up to the job it will be both frustrating and annoying.
Broadly considered there are three types of compressors that may be used in a home workshop. The first type is a simple motor powered compressor without any holding tank. These tend to be cheaper, and have low capacities- less air flow at lower pressures. While adequate for some light applications, these are not generally sufficient for a restorer.
The other two types both use air tanks to receive the air from the compressor and hold it until used. These tend to allow a smoother airflow and allow work at higher pressures for longer than a simple compressor might allow.
A direct drive compressor with a 25 liter tank. |
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The first of these is the more common: a direct drive system in which the motor is directly coupled to the compressor. These tend to be a little cheaper, but they are also a little noisier.
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A belt-driven compressor with a 50 liter tank |
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The second decouples the compressor and the motor, using a belt and pulleys to connect the two. This allows quieter operation, though these compressors tend to be a little more expensive. Of the two types the belt-driven seemed most appropriate: I anticipated working for lengthy periods in an enclosed space with the compressor, so the quieter ones had a natural appeal.
Having identified the type that was most suitable the issue of how large was the next to arise. The key point here is to identify the volume of air required by the most demanding application. reviewing the specifications of the tools, and those of the compressors lead me to believe that a 3 HP compressor producing roughly 14 CFM (9 free) would be adequate. In fact it was, but just barely. A skeptic may be excused for thinking that compressor manufacturers are optimistic when rating the output of their equipment- and the output produced may not be quite as much as advertized, and that air tool manufacturers match that optimism in estimating the demands of their equipment- and the input required may be rather more. So, I suspect I was comparing the absolute maximum available compressor output to the absolute minimum required tool demand.
For most of the applications the compressor coped admirably, but for that single "killer" application, it just wasn't enough.
A larger compressor wasn't necessarily a sensible proposition. The 3 HP compressor chosen represented the largest that could readily be supplied from standard household wiring. Larger compressors tended to require industrial grade wiring, and although some were available they would generally be much larger than my longer term requirements justified. The solution as I saw it was to double up on the compressors and run them in combination, feeding a single line from the two tanks. Thus far, the system has worked very well. I use the single compressor for most applications, and run the combination for my heavy applications. Once I'm done I can sell the second compressor.
In addition to airflow the size of the holding tank may be an important consideration. This can allow for a period of intensive air use- either high volume or high pressure, that the compressor might otherwise struggle to provide. In less demanding applications this allows a period when the air may be used without the compressor running. Larger tanks provide a greater capacity and flexibility. However the relatively small size of my garage dictated using a smaller tank.
Air Lines & Fittings
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How very boring a topic. Yet the air compressor is no good unless you can get the air to where its needed. Cheap air line can be bought- thin stuff, usually tightly coiled. Its OK and works, but seems more susceptible to kinking and sharp bends may restrict flow. I've found that the better quality, heavier duty air line is preferable. It does the job, no problems. I use two lengths- one for within the garage this allows the most efficient use of air since it doesn't have to travel through 50 feet of air line to get the 10 feet to where I'm sand blasting or painting. The other length can be connected as necessary to allow for the air equipment to be used outside the garage (filling tires, etc.) as sometimes needed. I use standard quick release fittings as shown in the photo on most all the air tools. This allows them to be quickly and easily connected and changed.
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Another eminently boring subject. I don't really know how regulators work, or the differences between the more expensive and cheaper ones or anything much use to anyone else. But a good regulator is supposed to be useful/valuable/essential for high quality painting. The underlying idea is that a smoother and more even air flow naturally allows a smoother and more even flow of paint.
Ditto the above for filters. I can better guess how these work, and what the differences between them might be. Again, a good filter is supposed to be useful/valuable/essential for high quality painting. The underlying idea is that a cleaner air flow avoids contaminating the paint- particularly with traces of the oil compressors use in their operation.
All this sounds more than reasonable to me, so I've got one- as shown in the photo it's a combination regulator and filter unit. Its wall mounted near the compressor and linked to it, the output may then be used throughout the garage. This also allows unregulated and unfiltered air to be taken off from the other outlet.
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Again a boring subject. And one that seems contradictory, given the desirability of using filters to remove impurities and specifically oil from the air used. Why then have something to put it in? Air tools often require a certain amount of lubrication- and oil contaminated air is one means of providing some. Hence in-line oilers may be had.
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An air powered cut-off tool. Think of it as a pneumatic angle grinder with a cutting wheel. The small wheel and vertical orientation allows access where electric tools won't fit.
I find the electric version more useable and effective, but this is good for small jobs and areas with limited working room.
Something of a miscellany here.
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An air gun. Useful for blowing dust, dirt and other odd things about. Useful for cleaning out holes that are otherwise inaccessible.
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A spray gun. Fill the canister with whatever fluid you want to spray and pull the trigger. Good for solvents and cleaning agents, though a bit messy. Not good for anything you want to do neatly or precisely.
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A tire inflation tool. A very useable, sophisticated version.
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An undercoat spray gun. No, do not undercoat the Healey. Use this to suck up the Waxoyl or Dinitrol and spray it into the various areas it should go. It has a vinyl tube extension that can be used to spray inside chassis box sections.
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I've used this to spray the Jensen-Healey's underside and must confess that it works very well indeed, with and effective and even spray. I warmed the goo first by setting it for a 1/2 hour or so in boiled water, with heated water added every few minutes to get it hot. I had thought about setting the cans in a pan or "steaming" them but good sense for once took over and a plastic bowl on the kitchen counter sufficed.
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An essential tool for dismantling a Healey. This is the ideal implement of destruction when it comes to separating panels. A hand held hammer and chisel might do the work too, or various pry bars, but the effectiveness of an air chisel is hard to beat. This will readily split most panels and while its crude and rough, a little butchery is often quite acceptable. If panels are heavily rusted and not to be re-used an air chisel can very usefully cut it out. On the other hand, more useable panels can be loosened (drilling out spot welds first) and the air tool then used to (more carefully) pry them apart.
(note: this is also covered in the page on media blasting)
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Media used in blast cleaning. |
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A typical blasting gun, with a canister holding a liter of grit. These are relatively cheap and effective and are useful for small amounts of blasting. There are drawbacks to using these for larger projects- the canisters only last about 8 minutes for more-or-less constant use. This can be a blessing for it lets the compressor catch up or rest. But it makes for poor productivity when dealing with numerous items and particularly for those that are very rusted and need a lot of cleaning. A further problem is that holding the gun with a canister of grit becomes very tiring- the grit is heavy and will soon wear the user down. The gun too sprays the grit everywhere. The advantage this gun has is its more effective use of the air provided- it doesn't have to suck grit from a distant supply. The rated air supply for this is 8 CFM, and either compressor coped with it reasonably, for short intervals.
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A "spot" blasting gun, the canister holds the grit, the bag at the front catches the used grit, and the various rubber nozzles allow it to concentrate on cleaning just small areas. This is basically the same as the gun above but designed for smaller jobs and to do them more neatly. The nozzles allow spots of roughly 3/8s and 3/4s inch diameter to be blasted, and for inside and outside corners the concentration of grit makes for a neater job. The cloth pouch also keeps the grit from being sprayed everywhere. This is probably the best solution for dealing with a few rust spots or limited areas that need cleaning. This too requires 8 CFM, but its not required for very long given that the gun is held directly against a very small area to be cleaned. I suspect that a smaller compressor would be able to manage given sufficient pressure in its tank. Its a very neat way of using sand blasting, though it still leaves a little grit and dust about....
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A bulk feed system- ideal for big jobs |
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This is the ideal solution for large jobs involving numerous items with varied cleaning requirements. The gun itself is light- the canister has been removed and the grit is feed through a hose and tube "feeder" that may be some distance away. This makes the gun much lighter and lessens fatigue, and it allows a much larger volume of grit to be employed so that the user need not stop to refill a small canister.
The one real drawback I see to this system is potential loss of pressure that sucking the grit several feet requires- the effectiveness of the blast stream must be reduced. This system requires 10 CFM, and the individual compressor almost coped... hence the motivation for moving to a system using two.
Not Yet Available, and should have a page/section entirely of its own.
Copyright© 2003 James M. Wilson All rights reserved.