Crack Repairs On Cylinder Heads
There are so many different methods: Tapered pins, Lock-N-Stitch, Seal Lock, Sealace, Brazing, Torch Welding, Flame-Spray-Welding, Spray-N-Weld, Thermo-Spray-Welding, Furnace Welding……
Have I made my point?
There is no right and wrong method for repairing cast iron or aluminum. Because there are so many variations of material and variations of repair problems, they will all work under certain conditions. The key is to know which is best for a long term solution.
Cold Repair: Has many terrific applications. It can be done whether in the combustion chamber or not. The pins we use are more durable than the head is. Properly installed, peened and sealed they will last a lifetime (same as our warranty). The gentleman (don’t tell him I called him that), that I hired 20 years ago is a wizard.
Aluminum Welding: Usually done with tig-welding. It takes the right alloy rod, right technique and the right equipment. Our welder is 70 something years young and he has been doing it most of his life. Do you think he’s any good?
There is also a new player in the area of aluminum welding. We haven’t finished our tests yet, but if successful, it will be terrific. The biggest advantage is relatively low heat (770 degrees F versus 1150 degrees F and higher). There is less distortion of the head and at high temperatures you can even change the metallurgy of the aluminum.
Thermal-Spray-Welding: There are many people who condemn this process. When you read what they have to say, it’s usually something like ‘we tried it a couple of times’ or something like that.
Ed Browder of Ed’s Auto Machine said “When I first heard about flame spray welding, I was very skeptical……attended Cast Weld Technologies school and …… very impressed with what I learned…… we can now recycle cast iron heads that have been taboo before.
95% preparation, 4% welding and 1% Murphy’s Law.
Furnace Welding: In 1983, I built my own home made furnace (because I couldn’t afford to buy one) out of fire brick. Chuck Saccett, here in Orlando, built me a burner. It was nothing more than a blow torch, but it worked. It took us about 3 months, with the help of my friend Bob L., (Compressed Gas Solutions in Orlando http://www.compgas.com/), before we worked out the right pre-heat, post-heat, temps, rod alloy etc. Back then we were doing a lot of Detroit Diesels(DDA). They cracked all the time. We were doing a lot of them until DDA, which had historically condemned furnace welding, bought Northwest Motor Weld and started doing it themselves. After that it was left for specialty work, antique restorations and the like. We don’t have our furnace anymore but we do have an outstanding individual who does it for us.