The hot water side of my bathtub has air in the line and makes this gawd-awful racket when I first turn it on, it also scares the hell out of the kids (2 year old twins).  I know that there is a fairly simple method to clear it out but I do not remembeer the exact procedure, any help you can give will be greatly appreciated by me as well as the childern   :)

Well if there is any air the pipe it should clear out after you run the water for a few minutes. The water pressure should clear the air out.
Or do you mean it is more of a pipe banging sound?

pipe banging,   I was under the impression that this was a sympton of entrapped air...

Replace the washer on that side.

Air in the water lines can cause water hammering.
The air will go away after the water has run for a while.
Did this just happen?
If so there might be a reason like if you had some work done on the piping in your house or if the water company did some work on their side.We had hammering when they did some underground pipe work in our area.
I'm a contractor and one thing we do when we work on water pipes is to vent out the air from a high point like an upstairs shower.
There is also a product that you can install on your piping .It looks like a tee with about a 10" capped off leg.
If you can't figure it out e-mail me with some more details and I'll help you trouble shoot it.
Good luck.
Andy

Look into a "Hammer Arrestor". Pretty easy to install.
Also, make sure your Temperatue Peressure Release valve (TPRV) is working. That's the funny looking valve with a lever and tag, on top or on the side of your water heater. It regulates the pressure to keep your hot water heater from building up excessive pressure. Had one blow up in Seattle this year. Destroyed a small building and sent the water heater over 100 yards across the street.
Warning, If you have not tested it before you may have to replace it soon after the test as it will not reseal. That is better than not testing and finding out the hard way that it failed.

The problem you decribe is called "water hammering" The cure is to install some "air chambers" at the highest point of the water line, ( if your house has a basement that may be right where the lines turn to go into the tub faucet,(at the faucet itself) remove the elbow and replace it with a tee,with the branch of the tee going into the faucet put the air chamber on top and the water line on the bottom,(I'd do the cold side too, while I was at it)These act as a sort of shock asorber and will solve your problem, you can get them at a plumbing supply house, or at Lowe's already made up, or you can make them your self, there also 2 types of these things, one is mechanical, and the other is just a peice of 3/4" pipe about 14-16" long capped at one end, and reduced down to usually 1/2" at the other end, it works simply, water pushes against the air trapped inside,and the air asorbs the shock,Problem solved, the mechanical ones do the same thing but, they have a diaphram and a strong spring and are alot smaller, and more costly, if you can sweat copper pipe you can make a set up for about $2.00 in fittings and whatever some 3/4" pipe, solder and paste ,sandcloth will cost, the mechanical ones last time I looked were about $15.00 each,either will work just depends on how much you want to spend and if you can sweat copper, (assuming you have copper water lines) if you have galvanized screwed pipe as your water piping then the problem is a little more complex, you still need the air chambers, but you'll also need 2 pipe wrenches,(12-14" wrenches will do just fine) pipe dope, teflon tape,pipe fittings, and carefully look the system over, find the highest point, and thats where you want the air chambers, I'cant tell you how to pipe it up without seeing the system so you'll have to figure that out  

I'm not a plumber, but my wife's family has some apartments that I help take care of.  That's water hammer.  There is suppose to columns of pipes in the plumbing system to prevent that.  The reason for this banging sound is the momenteum of the traveling water when you suddenly shut-off the water flow. There is what the plumbing trades call air columns, i.e. vertical pipes with air in your walls that act as shock absorbers.  The traveling water compresses the air and acts as cushion. I think the air column pipes have filled with water, which prevents them from acting like a shock absorber. You need to put the air back into those air column pipes.  You can fix that by turning off the water at the main house in-let, and opening a spigot/faucet usually a garden hose outside at the lowest part of the house and a bathroom faucet(to break the vacuum) until there is no more water running out. Turn off all of the open valves. Now GENTLY open each faucet in the house because you will get sputtering from trapped air etc until the air is gone from the pipes but not the air columns.

You should fix that water hammer, it is hard on the pipes because of the vibrations.  I hope that helps, it not you should call a professional plumber.

thanks for all the replys guys,  that why I love this forum!  I did the quick and dirty procedure Warlord suggested and the prob appears to be resolved for now.  I relly appreciate all the excellent advice from those of you who have -been there done that-:)
crazy Jim out

Cool, glad to be of service, the quickest and the cheapest. This forum is not just all just firearms, there is a little of everything for everybody.

If you start hearing pig like noises coming from the walls, it is a sign of the possible presence of malevolent entities.