Making Trim
Hi Ron, I always enjoy reading your column and articles in STREET RODDER. In the April issue you answered a question about making trim pieces. A few years back I was working as a tool and die maker. We had a small can-making line that we would sometimes modify to try out different operations for our customers. Stainless steel rails that guided the cans surrounded the track work that the cans traveled on. This rail was a stock item that we ordered from Ryerson (call (773) 762-2121, or visit www.ryerson.com). It was kind of a half-round shape that measured about 5/8- or 3/4-inch-wide and was about a quarter-inch thick. It looked almost exactly like the piece in your column's lead photo, and it came in 20ft lengths. I remember that it was a smooth, cold-rolled 304 stainless. We used a stud welder to attach 1/4-inch stainless steel studs directly to the flat side so we could bolt it directly to the required brackets. I always thought this material would be ideal for automotive trim.Tony BabiakVia the Internet
Thanks for the lead on the stainless half-round stock, and for the idea of using a stud welder-this would be an ideal way to make special trim for many automotive applications! Ryerson currently lists only 1/4-, 3/8-, and 1/2-inch stock, but perhaps other manufacturers have other sizes.
Bad Gas
I read your article in the May issue with a letter from someone who had discovered that he had purchased a new tank of argon only to find the gas was contaminated. Being in the welding business for nearly 50 years, I know that when most gas suppliers fill new or used cylinders, they are placed on a manifold that holds anywhere from 10 to 30 cylinders. A vacuum is pulled on all the cylinders, new and used. Once the proper vacuum is achieved, the cylinders are filled with argon gas. It would be very unlikely to have one bad tank out of all those cylinders, because any contamination would be spread through all the cylinders.
I had an additional thought about what might have caused his problem. If he purchased a new tank from a distributor and it wasn't a 150 cubic foot cylinder or larger, the distributor may have attempted to transfill the cylinder. That's where he hooks up the smaller cylinder to a larger one, opens both valves, and equalizes the pressure in both cylinders. This would contaminate the argon gas in the smaller cylinder if it hadn't been evacuated.
I have seen the problem of porosity in welds before, and it is sometimes caused by a small leak on the low-pressure side of the welding system, which could come from a loose fitting or a pinhole in a hose. A leak like this can be diagnosed by waiting until the argon solenoid shuts off, and then watching the ball in the Thorpe tube on the argon flowmeter to see that no flow continues and the ball is at the bottom of the tube. If the ball doesn't settle quickly, there is a leak in the low-pressure side of the welding system. When welding, a small leak can suck air into the shielding gas, contaminating it, and causing porosity in the weld.