KentPDG

You might try to build one from an old vacuum cleaner. They blow as well as suck, in fact the sucking and blowing are equal. Scrapped vacuums are cheap to free. You could control the airflow with a butterfly valve, which is pretty easy to make if you couldn't find one at the heating/ventilating department or shop.

I am interested in how to case-harden some very thin sheet steel. Specifically, 28 gauge (.015") low-carbon sheet, 1010 steel. There is quite a bit of this material requiring treatment. I want to do it as a backyard project. The material will be cut to a specialized shape, then polished using various grades of silicon carbide. After that, I want to give it a very hard surface. My initial thought is to build a special container of aluminum, place the parts inside (with suitable separation), and fill the container with powdered charcoal, possibly mixed with boron carbonate. This would be placed into a suitably sized firebrick oven, surrounded with charcoal. After igniting the charcoal, I would fan it with a blower or perhaps with compressed air. After a period of heating (which is an issue where I need advice), the container would be removed from the oven and taken off of the steel parts. They would then be lowered into a barrel of very pure water, for quenching. After cooling, I would re-heat the material and air-cool it, for tempering. The questions are: 1. Would this work, or have I missed something crucial? 2. Is there a way to limit the depth of the hardened case, or will this thin material just get hardened fully through? 3. Can I estimate the temperature inside the oven by monitoring the color of a sheet of steel above it? Or will I need to obtain a pyrometer? (I have one, but it only goes up to 800 degrees F.) I would be grateful for comments, suggestions, and advice. Kindly, Kent

Hi Folks, Just stumbled onto your site, which seems to cover lots of areas that interest me. I'm a retiree, former independent management consultant, trained as electrical engineer (BS, MS) and retreaded as Harvard MBA. Wide range of personal interests and activities. Right now, I'm engaged in a complex project that involves a considerable amount of metalworking -- aluminum, steel, titanium, maybe a little brass or copper. Doing the work at my Vermont home, where I have a variety of metalworking tools: lathe, drills, vertical milling machine, welders, 36" slip roll, dynamic balancer, bead roller, power saws, planishing hammer, English wheel, and various hand tools. I'm here to ask for advice, not to pose as an expert on anyone else's problems and needs. However, if anyone is in the area and needs the use of tools I have available, let me know; willing to share. Looking forward to some good help from the members here. Kent, PDG