For the guys who work on ATV's and motorcycle engines and even those who work on lawn mowers, boat motors, chain saws, radiators or any other aluminum products.
Have you ever wanted to repair a cracked aluminum engine case, cover or housing? I have on numerous occasion wanted to close a hole or seal a crack without going to a welding shop to have the part TIG welded. TIG welding is perhaps the best fix, but there certain locations where TIG welding may damage the part while repairing it. Case in point; one half of an engine case cracked below the crankshaft from a rod bearing failure, a piece of broken piston or other solid object hammered into the case from rotation of the crankshaft. TIG welding will fix the crack, but the heat will deform the sealing surface and cause a gap between the parts when assembled.
If the unstressed part could be soldered or brazed with a propane torch, the repair would be adequate and the reduced heat would not warp the piece.
I watched a demonstration of brazing aluminum with a propane torch at a trade show. I was skeptical and shrugged off the demonstration as a professional welder displaying a skill the average person does not have as he brazed a hole closed in the bottom of an aluminum can. I scoffed about the demonstration and was asked about my ability. I have had training in welding, can fusion weld with an acetylene torch (said to be a lost art), can braze well and my training in electronics has endowed me with the ability to solder very well. I said,"I can solder and braze." The demonstrator asked me to try it.
Using a common propane torch, I heated a piece of 1/4" x 1" aluminum bar and as instructed, did not heat the rod and only the aluminum stock. At a certain point, the rod melted on contact with the aluminum bar. The trick was to keep the bar stock hot enough to melt the rod without applying heat directly to the rod. I laid a nice uniform bead similar to brazing with an acetylene torch. I then proceeded to brazing a hole closed in the bottom of an aluminum can (the bottom of the can is the thickest part). I successfully closed the hole. We then crushed the can - the braze did not come loose. We then drilled the braze. The braze was appx. 10X harder than the raw aluminum.
I now have a new tool in my shop. I repair engine cases and other parts in non critical and unstressed areas. If the part can be accessed from both sides, I can fill bolt holes, drill them and tap them for drain plugs, screws or just close a crack or unwanted hole. Using my vertical mill, I can resurface a repaired part to almost like new condition.
There are many sellers of aluminum brazing rod and like all welding products, some are better than others. I only have experience with one supplier and am satisfied with their product.
Go to your local welding supply and ask for aluminum brazing rod or get on Ebay or Harbor Freight Salvage and choose a product there. I advise you not to buy the cheapest product you can find as the higher priced products are better, stronger and easier to work with. I pay about $75 for 20, one foot long aluminum brazing rods. They have saved my customers hundreds of dollars and me many hours of time.
