Buzzkill

That really tickled my funny bone. So much said in such a short post. Made my day. Thanks

The search function on this forum doesn't function well. Try a web search using "iforgeiron" as part of the key phrase. Start with "making a 400lb anvil." After that all I can suggest is paging down through the topics in the anvil section of the forum until you see a topic title that catches your eye. There are quite a few regarding making anvils though.

In my case it's a bottom blast forge, and I don't know if the others using a bathroom fan were side or bottom blast so that could be a difference as well. I was burning anthracite rice coal from TSC and had no problem ruining the blade I was working on due to overheating. Since I have no experience with a side blast system I'll let others handle further suggestions. I was wondering what that "ninja" thing was all about. Thanks for explaining!

I use a blower from the power vent of my last hot water heater. It's not dead quiet, but it is not nearly as noisy as a Dirt Devil. Others on here have posted that they use bathroom vent fans successfully, and I believe those would be significantly quieter as well. They should be fairly inexpensive and available at pretty much any big box home improvement store. Of course the often-used hair dryer is also an option, but they tend to be a bit noisy as well - and can get you in trouble with the spouse if you take hers without permission.

Thanks for the tip. I believe that is exactly what was happening. You shouldn't be. As far as I'm concerned, your box of dirt post and another rail road iron anvil thread are "must read" information for anyone starting out with solid fuel and no anvil yet. Good stuff.

If all you can find is galvanized bolts then toss them in a container of vinegar for a day or two, rinse with water, hit them with some baking soda on a tooth brush, rinse again and use them. The vinegar will strip the zinc off the bolts and the baking soda will neutralize the residual acid from the vinegar.

If you have any of that file left over you can do a rough shape on it, heat treat it like your finished knife, and then test to see how well it holds up. If you clamp it in a vice with an inch or two sticking up and tap progressively harder on the sides with a hammer you'll get an idea of whether it will bend before snapping. If you do that wrap a rag or something around the blade so metal shards don't fill the room with flying shrapnel if it shatters. Some old files have carbon content of 1.2% or even slightly higher, and they can still stay fairly hard and brittle even after the temper cycles you describe. Regardless, it should hold an edge well for you and it's a handsome second knife.

Yes, I can see that one now. That's pretty good, especially for a second knife. I'm sure you're aware of the potential stress risers from file teeth, but if the knife sees little to no impact there shouldn't be any issues if your heat treat is good.

Not for me. I couldn't see the first one or the last one. I just get a string of alphanumeric characters.

The forum is eating my posts, but do a Google search using the following "iforgeiron just a box of dirt" and read through that thread in its entirety. That should answer a lot of questions you may have about side blast forge construction. After that you'll be in a good position to ask more specific questions of someone like Charles Stevens to tweak your specific design.

It's a little bit hard to tell how deep your fire pot is from the pictures, but the size and shape of the pot didn't strike me as particularly troubling. Think of a sphere roughly 6 to 8 inches in diameter. That's roughly how big the burning portion of your fuel should be in operation. Part of that will be down in the pot and part of that will be above the rim of your pot in the fuel you have mounded up on top. This is needed so you can access the neutral to reducing part of the fire ball which is roughly the top third. You want to be able to lay your stock pretty much horizontally through the fire in that region. If it's tilting down into the fire you are potentially getting into the oxidizing area of the fire ball which can turn your project into a burnt steel mess fairly quickly. If you are just laying the stock on the very top of the mound then you are wasting a lot of fuel and again you're not in the right area of the fire for forging. That is why we suggest having the slots on opposite sides of the fire at the correct height. You should be able to determine fairly quickly where the correct height is for your forge. If you build your fire and fuel mound the same way every time then the correct spot in the fire will be pretty much the same every time as well, but this is affected by the depth of your pot, so we can't give you an exact measurement to go by.

"Another thought I had was, what if I lined the brick with a sort of refractory fire clay mixture? Might that fix my heating issue? " Not likely at all. The only purpose of claying a fire pot (typically cast iron) is to protect the pot from the heat generated, not to increase the fire temperature - for a solid fuel forge. A propane forge is a completely different animal in the way that heat is transferred to the stock, so refractory lining becomes an issue there. You've probably seen this stated before on this forum, but for a solid fuel forge all you need is a hole in the ground and an air supply. We build forges only to raise the hole in the ground up to a convenient working height. What bigger heat sink is there than solid earth all the way around a hole? If your pot is the right depth and somewhere near the right amount of air is blowing into the fire, it will get hot. Either too little or way too much air can cool the fire though, but between those two extremes more air = hotter fire. If you have so much air going into the fire that it is moving your fuel around you definitely need to back it off quite a bit.

In the picture at least it looks like your blower is directly below your fire pot. Especially since you show a fairly large unrestricted hole, that will allow ash, clinker, molten metal, etc to run straight down into your blower. This could damage or destroy your blower, but also you could end up with a plugged air path. Typically you'll see a "T" fitting at the bottom of the fire pot so that the blower can be mounted off to the side more or less horizontally and an ash dump straight down from the fire pot to avoid this problem. I wouldn't worry about the bricks being a heat sink with either charcoal or coal. The fire should be contained in the pot itself and the combination of ash and unburned fuel provides some insulation effect. Regardless of whether it's open air outside the fireball area or thick rocks, that should have no noticeable impact on the fire temperature itself. That is governed by the shape of the fire and the air blowing into the fire. However, based on your pictures I don't see a good way for you to get stock down into the correct zone of the fire for heating once you have your fire ball established. As long as those bricks are just a loose stack that is no problem since you can create gaps on opposite sides of the fire to feed your stock into the fire at the correct height. It will probably be easier for you if those are vertical slots or V shapes rather than just a gap part way down though. It might be a good idea for you to have at least one bar or some other restriction across your opening for your air gate though. One preferred method on here is the use of a domed pipe cap with a number of holes drilled into it. The dome shape allows the slag/clinker to run down around the cap in a donut shape and avoid plugging up your air holes. With a wide open bottom hole anything that is heavy enough and has low enough air resistance will run into the opening and down your pipe even with the blower on.

How do they sound? I'm pretty sure I know what you meant there, but that did spark an interesting picture in my head.

Could you clarify this? You didn't really define what the problem is as you see it, and for me at least that makes it difficult to suggest a solution.

I'm guessing neither of those has been up against some large elm logs. That was some of the most frustrating wood to split that I've run into. For wood that splits as easily as they were working with a simple splitting maul would be about as fast.

Will it work? Yeah, kind of. Are there much more suitable objects to use that will be as cheap or cheaper and the same weight or less? Definitely. The more solid steel (not edge welded, stacked, etc.) directly under your hammer blows, the more force will be transferred into the hot steel you are beating on and therefore the more you'll move steel with the same force. I beams have a very narrow section where there can be steel under your hammer blows no matter which way you turn them, so while you can make it work, they are far from ideal. A large sledge hammer head mounted in a stump, a solid chunk of even mild steel, an axle with a diameter of 3 inches or larger mounted vertically, forklift tines, rail track on end, etc. - all of those are better options by far than an I beam.

Ranmatt, welcome to the forum. Just a couple comments here. If cost is an issue for you at all for the forge components and then for operation I'd suggest going a bit smaller than that. After building one that seemed right to me when I started, but was really far larger than needed, I built one from a disposable helium tank - which is also the same size as a freon/R134 tank. I mainly forge blades and have been able to forge everything I've attempted in it so far, with the largest being a kukri style knife with an overall length of about 23 inches. Blown burners are dead simple to make and you quickly learn how to adjust them, but you do have adjust the air every time you increase or decrease the fuel in order to maintain your preferred forge atmosphere. I used one for a while then went back to naturally aspirated, mostly because I forge outside and like to be able to move to shaded areas without power cords and/or tubing for air being an issue. Your comment about forced air being less likely to freeze up the propane tank is inaccurate. Whether you are using forced air or a naturally aspirated burner, if the fuel to air ratio is proper, it will take the same amount of propane to get the heat you want in either case. The difference is the naturally aspirated burner will have a small orifice to introduce the fuel to the burner and it will be running at higher pressure (most likely) than the blown burner. However, the amount (volume) of propane leaving the tank is the same in either case. In the blown burner it's typically lower pressure at the fuel inlet for the burner, but that's because it's entering through a much larger diameter tube. Remember, you can typically only work on about 6 inches of hot steel at a time before it cools to the point where it needs to go back into the fire. So if you have a forge with a slightly longer chamber than that and a pass through opening at the rear of the forge you should be able to work on any length of straight stock that will fit through the openings. Obviously if you are working on oddball shapes then opening and chamber size become more of an issue. Spend some time reading on here and head over to Wayne's website and you'll get lots of good info. And yes, I would give up the idea of one forge for all. It's tempting, but normally things that are multipurpose can do several things in a mediocre way, but probably none of them as well as you'd like. Again, start small. Why spend more money on building supplies and propane to run 2 burners if you can do what you want to do with lower startup and operating costs?

I wouldn't knock either of them too much. It costs little or nothing to ask that way, you can reach a fairly large audience, and if you're looking for one to use rather than resell you only have to get lucky once. Although the chance may be slim of getting what he wants at that price it's significantly better than if he didn't put it out there at all.

Right. I too am offended by all those people who are so easily offended. At the same time I will not tolerate intolerance.

You may have covered this before, but it came up in another thread so I thought I'd ask it here: For the purposes of calculating forge chamber volume to determine the size and/or number of burners needed to properly heat the forge, should you deduct the volume taken up by things such as fire brick or kiln shelf? I know they are initially heat sinks to some degree but then they help radiate heat back to the steel, so I'm not really sure how to treat them in those calculations.

Ahh, so the diameter you gave us was the outside diameter. On the fire bricks I'm not sure you should subtract them from your calculations. If they are inside the insulation then they will be part of the forge that needs to be heated - and full size normal fire bricks are big time heat sinks. However, once they have absorbed the heat they will help radiate heat back into the forge. Frosty or Mikey might have a better idea if they should be excluded from volume calculations for the purpose of determining how many burners you need. Regardless, it sounds like you're willing to abandon the behemoth pipe idea and travel down a more economical path, so kudos and good luck.

I didn't subtract any length for the refractory on the 2 ends, but lets assume you decrease the length of the chamber by 4 inches on each end due to refractory and the curvature of the domes. That still leaves you with 18 inches in length and over 2000 cubic inches of chamber to heat, requiring about 6 three-fourth inch burners to bring up to temperature and keep it there.

Hmm. You might want to check your calculations. Based on what you told us you'll end up with a 12 inch diameter chamber after adding your lining. The radius squared times pi times the 26 inch length is more like 2940 cubic inches unless I did my math wrong. If I did my math right that would require 8 to 9 three fourths inch diameter burners to keep hot. It will also require a lot more kaowool and refractory to line that beast. The point is you're planning to spend WAY more money up front AND way more money to operate it than needed by a very wide margin. My advice is to hang on to that pipe for some other project and scale your propane forge down to BBQ tank size or smaller until you know what you really want/need.