LeeHene

I guess I could track down a local supplier. The place I fill up has a tank about as long as a small bus and the diameter of... uhh, a normal propane tank that length.

Frosty, I had no idea, good to know! I've been getting my tank refilled at a local hearth and patio place. I believe their tank is filled by a national propane supplier for business and residential.

The only reason it concerns me is because the flame breifly shifts to greenish color when it does that. I wonder if it's causing more scale on my work than it would otherwise. Im still trying to get forgewelds down, so anything that would make it easier for me is a plus.

Hey guys, something I've noticed from day one is that my flame seems to flicker slightly, regardless of the level of propane, forced air burner or venturi, pressure setting of the regulator, or any range of valve settings. Is that normal or do you think it's the regulator fluctuating? (No frost on the tank.)

Gotcha! So the cracks ARE something that needs to be dealt with promptly? Thank you for correction on the ceramic wool. I'm not sure why I keep referring to it as fiberglass.

Hey guys, another quick safety question... When I first put the forge together, I didn't spray the fiberglass wool with rigidizer, I simply coated it with the HellCoat that came with the forge kit. I tried to do reccomended curing time and slow break-in, but cracks formed after firing it up a time or two. Coated it all with 100HT a short time later. That cracked in the same places after a few uses. Do you think the cracks pose much danger for airborne particles while forging? They close up a good bit once the liner heats up, but I still don't want to expose my son to something potentially cancerous! (I did search for an answer, but pretty much every result partained to new forge construction.)

Good information guys, thank you!

Mikey, several posts back you mentioned unburnt fuel and leftover superheated oxygen can cause scale. I was only aware of oxygen causing it. So too rich OR too lean can both cause scale to form?

We were using some salvage steel given to us from tines of an old farm implement. I tried quenching a small piece in canola but it failed the file test. We then tried Parks 50 (in the video) but it still didn't skate a file afterward. Last, we quenched in water, and that did it. It's in the oven now, finishing the last of two heat cycles at 400⁰F. Working steel has a steep learning curve.

My son just quenched his first knife blade! I hope it turns out ok. It was hard to get it all heated evenly in our small forge.

The main run to my burner is 1" black iron. Propane is fed in from a simple tee. The 90⁰ fitting before it goes into the forge is also a reducer for the 3/4" burner tube. The burner tube is 6" long. The diffuser is made of four 3/8" OD pieces of hydraulic tubing, 1 1/2 inches long. I tack welded in sets of two, then tacked the two sets together. They didn't fit, so I spent a lot of time with the Dremel. Once I got them to at least start in evenly, I flipped it over onto a chunk of wood and gently persuaded it all the way in with a 3lb sledge. 1/4" OD tubing would probably fit about perfect, but I used what I had on hand. Im still not 100% happy with stability of the mixture. At times it fluctuates between green and blue. I think my next step will be adding a twisted piece of flat stock inside the 1" line to help agitate the propane and air more. I can confidently say that this setup would supply two 3/4" burners, without a doubt.

I'd be happy to share! For the forge walls I used Hellcoat 3000 that came with it to cover the fiberglass blanket. (I don't think I'd reccomend the Hellcoat. I'm still haunted by some bad cracks that started in it.) A couple weeks later I went back over it with 100HT, which is GREAT stuff. For both, I mixed them about as thick as a milkshake. I tried to apply an even coat and followed over it with a thick paint stick as a float to smooth it out. To prevent getting any on the outside frame, I used blue painters tape. Gotta take that off immediately afterward though. If you wait until the coating sets up, removal will result in some cracks and/or voids. Always leave a little bit extra. There will be spots you might want to go back over or repairs to make in the future. I hope this helps someone. It can be a little intimidating at first if you care about doing a nice job.

Thank you Mikey, that means a lot! After some use, I think I'm on the right track. It's not quite as forgiving with settings on the high end, but it now it's able to be throttled way down and still run reliably without the flame traveling up into the burner tube. (That black soot is just from momentary flames rolling out the front during transition between low and high.)

Today I finally got around to adding a diffuser. Hoping it will add stability and help hold the flame at lower temps. It sure required me to open up the regulator a little more! Im not really sure if I like the flame output better or not. The flame is a little more sensitive to the mixture once up to temp and it certainly concentrates heat in the middle. Guess it'll take some use to decide.

Quick update, I got a bench top stand welded together for the forge. It allows an air gap between hot surfaces and the bench and it also holds firebricks in place for the doors. Simple and 100% adjustable / removable.

Of course I have a fire extinguisher close by. It's mounted right beside the door, 5 feet from the forge.

Thank you for the input. I've been planning to build a fixture out of angle similar to what you mentioned, but I was going to keep the bricks pretty close to flush with the forge. Since installing the blower I have observed no issues with back pressure. Even when testing with both ends briefly blocked, the flame doesn't even sputter. Is there more to adequate venting (beyond burner performance) that I'm not aware of? Carbon monoxide or something? I ask that respectfully. I still have a whole lot to learn. *I do plan to coat ALL new surfaces facing the forge with 100HT. That stuff is magic!

Today I inserted a fresh firebrick in the bottom that I'd cut to match the conture of the forge. I hadn't coated it with 100HT yet. WOW! WHAT A HEATSINK!!! No wonder some folks can't manage to get their home-built forges up to temp! Small details add up quickly.

Cheating is only an issue if someone is looking to compete in a fair fight. Personally, I'll take a strong victory over a fair fight any day. Guess that might explain why I've never had any interest in organized sports.

Sorry Frosty, didn't mean to rub a sore spot with that last post. I'm happy with my little plastic blower but I sure wouldn't trust it's build quality enough to put on a burner that I was selling to someone for that kind of money. I completely understand why it irritates you to see your time and research used for the sake of stuffing someone else's pocket from poorly made versions of you work. I'm a stickler for quality too. As much as the OEM burner of my son:s little forge frustrated me, I've gotta say, the frame is thick and solid with nice welds. That's what attracted me to it in the first place. It seems so few people take pride in their work any more.

I was googling "forge forced air burner nozzle" for design ideas and look what I ran across. Ouch! They're taking folks to the cleaner with that burner.

Thank you guys, that means a lot. There is so much great information on this site, it really makes it easier to learn and develop a starter design. The size of the forge is plenty sufficient for what we need right now. Next I plan to build a frame for sliding doors on the front and back. I've gotta get that anvil stand more rigid. I'll probably experiment with the burner nozzle after that. As for a ribbon burner forge, that might be something for another time, but not now. My son's interest is in making knives, and this little forge seems just right for that. We need to find someone local for some hands-on pointers on moving steel.

Quick update: I installed a gate valve for air and a needle valve for the propane. The picture is a low-ish flame. I had trouble balancing air/fuel for low heat before adding the valves. It's going to take a little practice to get the hang of adjustments, but I'm pleased. Thank you Frosty and Mikey for your help!

I didn't say no blacksmithing equipment in the barn, just no cutting a hole in the floor to anchor our anvil stand in the ground. -hahaha!