Buzzkill

I'm not trying to discourage you from using a mechanical means of extraction. However, if glyphosate is applied as I described (concentrated liquid brushed on to a freshly cut stump), there is no wide area of effect above ground. You could even cover the stump with plastic for a week or two to prevent wildlife from reaching it. Glyphosate is generally considered to be of low impact on animals and humans as well. If you are dealing with a plant species that consistently sends runners up from the roots it is difficult to eliminate and may take several years of consistent extraction in order to completely eradicate it.

Is glyphosate (Roundup) legal to use where you are? For stubborn trees I cut them off and use a paint brush to apply the concentrated herbicide to the stump. So far that has worked for me on everything, but in a couple cases roots must have been in contact with the roots of other trees. It didn't kill any of those trees, but they were in distress for a couple years afterwards.

To the best of my understanding Frosty has it right. If the two metals are bonded properly, as in a solder or brazing situation, there is no opportunity for any electrolyte to get between them to cause corrosion. However, at the edges or any other place where there is even the slightest opportunity for something to get between the two metals it is likely to occur over time. Generally speaking though, if the piece is kept dry, or is lightly oiled, you should not see any galvanic activity between the two metals in the scenario you presented.

My experience is exactly opposite. Hardened high carbon steel etches dark/black, with low carbon steel etching as gray.

Looks like you nailed it! The only suggestion I have is to build a support to secure the burner/mixing tube in place.

The only "solution" I've found to this issue so far is a deep block with a lot of very small flame ports. My current burner has about 3" between the flame face and plenum and has around 180 holes of about 1/8" diameter, and I'm using a 3/4" mixing tube. I couldn't get a great shot of it, but here it is shortly after firing up at very low pressure. I've been able to crank it up to welding heat then back down to barely running without any burn back into the plenum. I can light it back up after being shut down without a problem. It doesn't pop when I shut down the gas either. It's not perfect and I do get some flame lift at the bottom of the burner block at first (as you can see), but overall I'm happy with it.

Very cool. Building an epoxy top table is still one of those many things on my "to do" list. How's the weight on something like that? I'm assuming that moving it is a 2 man job.

In simplest terms a flux core MIG welder does not require any shielding gas. MIG welders that use solid wire do require shielding gas for successful welding. Flux is included inside the wire, hence "flux core." This is comparable to the external flux on electrodes for "stick" welders. A welder designed to only use flux core wire typically does not have the hardware necessary to use shielding gas. Some welders can accommodate flux core or solid wire with shielding gas.

What thickness (thinness) have you actually achieved so far? If it's mild steel it should be possible (but very labor intensive) to work it cold and thin it out with the right tools and techniques. You may want to work along an edge with blows that are about half on/half off the steel (but fully on the table of the anvil) to see if you are getting anything done. Sometimes you are doing more than you think, but it's difficult to detect small increments of movement. As for the "floor goo," there are 2 things I've seen that can make that happen. The first, as Frosty explained, is the use of flux for forge welding. The other is the use of refractory cement or mortar as a flame impingement surface. In both cases they get sticky at heat and then turn into a hard, almost glass-like, substance when cooled. When you are working really thin stock it is sometimes best to not have a screaming hot forge. It's really easy to overheat or burn thin sections of steel. As long as it's mild steel there's not much down side to working it a little too cool - just the wear and tear on your arm. If it's medium carbon or high carbon steel, then working it too cool can result in cracking.

Is your motor single phase or 3 phase? The reason I ask is I don't think a VFD will work on a single phase motor, but I'm not 100% sure. It looks like there is a box for a capacitor, which would mean single phase, but I've learned not to assume too much. I've been wrong too many times. 1.5 hp is the typical cutoff point for 110v circuits as well, which also points to a single phase motor.

Without knowing the surface feet per minute of belt travel it's hard to do an apples to apples comparison though. For instance, if your drive wheel is 3 inches in diameter, that would produce a much lower number than his 5 inch drive wheel. It may be significantly harder to stall your 1 hp motor than his 1.5 hp motor in that scenario. If your motor is rated around 1800 rpm, and his is a 3600 rpm motor that would also change things significantly.

There is a hinge on the tension arm idler pulley mount. If you are using a 5 inch drive wheel you may find you can stall the motor, but probably only if you're being aggressive with it. You can always drop down to a 4 inch if that happens. Otherwise it looks like a good build to me, and I think you'll wonder how you got on without one for so long. As far as a VFD goes, I do recommend them. Being frugal as well, I went with a cheap chinese one I got online. However, those are not designed to operate in the environment that exists around a grinder. If you buy one of those make sure it is rated for at least 50% more hp than you plan to use, and build an enclosure to keep all the dust and abrasives out of it. It has to be large enough for the heat to dissipate or you have to have heat sinks exposed to the outside air if you will be using it for long. FWIW, mine is still functioning more than 5 years later. However, when/if I need to replace the VFD I'll probably go with the NEMA rated version that was designed for that type of environment.

He could destroy an anvil with a rubber mallet. Usually the word "destroy" is replaced with some language not appropriate for this website.

I concur with the others. One HP is bare minimum and that is borderline. 1.5 to 2 hp is a good place to be. I used one of those combination 4x36 belt sanders with the disc for a couple blades. They are not designed for metal work and will not hold up for long in that application. Those are mainly for woodworking applications.

Hard to judge heat by pictures. The colors tend to appear differently in photos than they do in person. Too much work maybe. I've worked a few of those leaf springs that are 3/4" thick and 3" wide. That will wear you out if hammering by hand. FWIW, I've split some of those length wise, and they are much more manageable that way. Of course if you have a power hammer and/or press you probably don't need to bother splitting them.

It looks fine to me. All 4 tanks come to a manifold before the regulator. He has a bypass fuel line and a solenoid controlled fuel line, which probably means he's using a PID controller for temperature regulation.

If you are only running one 3/4" (or even 1") burner that will probably work well. However, since you are in MN, if the temps drop significantly below the freezing point for water it could still result in some freezing issues with your propane setup. I have 2 BBQ propane tanks linked for my forge and don't have any freezing issues, but I rarely fire up the forge when it's bitterly cold. For me it is a hobby after all.

Silver plating tends to be a very thin layer. I doubt there is any reasonable mechanical way to remove it and preserve the silver. The melting point of pure silver is lower than pure copper by a couple hundred degrees F, but if either of those are alloyed with other metals that could change things significantly. Brass (being an alloy) has a range of about 300 degrees F melting point. Some brass has a melting point lower than silver, and some higher depending on the composition. That leaves (I think) only a chemical solution. You'd need something that will dissolve the silver, but not the copper or brass. Then you would have to get the silver back out of solution into solid form to do anything useful with it. Nitric acid will dissolve silver, but it will also dissolve copper. I think hydrochloric (muriatic) acid will dissolve silver without dissolving copper, but I'd have to do a little research to be sure. I hate to say it, but I doubt you will find a cost efficient way to remove the silver plating and retain it. If you are just trying to get rid of the silver plating for some reason, you could use abrasives or a chemical approach, but I'm fairly sure that will cost you more than it's worth in the long run.

Joining dissimilar metals is sometimes tricky. If you are soldering or brazing then surface preparation is paramount. You must have a clean, unoxidized surface to have a chance there. The right flux helps a lot. However, if you are not having much success with those methods you should be thinking about mechanical connections, such as the pop rivets mentioned above. You could also make your own rivets from bolts or round stock of the appropriate metal and peen them into place (if the rivets are small enough and you can support the bottom side while hammering on the top). Beyond that you can be creative and use wire wrapping or other techniques. If done well, it may even enhance the artistic impression of the piece. Generally speaking, you can't weld steel to aluminum or brass. As I understand it, this can be accomplished with explosive welding techniques, but that is typically done with flat sheets of metal - and of course requires knowledge and skill in using explosives properly. Another thing to keep in mind is that dissimilar metals in contact with each other will often experience corrosion due to galvanic activity at the site where they meet. This is especially true if they will be exposed to moisture, even high humidity.

What are you doing (or planning to do) that requires that much length? For me it's more important to have height and width to accommodate odd shaped pieces. Long pieces can pass through the back of the forge. I rarely need more than 6 to 10 inches of steel heated at a time, but you may be doing something entirely different than I do. As you've indicated, more length means more burners. More burners means more fuel cost - and possibly iced up propane tanks. To determine the number of burners you need to calculate what the forge chamber volume will be after adding all your insulation and refractory. You'll want one 3/4" (well built and tuned) naturally aspirated burner for every 350 cubic inches of volume you have in your forge. If you do install more than one naturally aspirated burner keep in mind that they can interfere with each other, especially if placed too close together. At the intake end they can compete for air if not oriented correctly, and on the flame end the back pressure from one can affect the performance of another. If you have some basic tools and shop skills you can build Frosty's T burners. That's probably the best bang for the buck. Of course it helps that you can discuss any problems you have with the guy who designed the burner here on this site. Here's the link to the topic that has the plans: https://www.iforgeiron.com/topic/43976-t-burner-illustrated-directions/ I don't have any experience purchasing burners off the internet, but maybe someone else here can chime in.

Looking forward to seeing the results. I'm curious how tightly you can control the temperature in the 1900 to 2000 F range.

What are you trying to accomplish by annealing? If all you are trying to do is drill holes in it then there is an easier way. Heat to a little below critical temperature (usually a dull red) and then throw it in the vermiculite. That's more of a high temperature temper rather than annealing, but it should allow you to drill holes. If it doesn't then the carbides are probably the issue and you may have to go the slow route to get what you want. If you are annealing for other purposes that may not be the way to go. Rockwool insulation (at least the stuff I have) is rated up to 1200 F. So, if you want to build an annealing box you could use that to line it, maybe cover it with sheet metal if you think you need it then fill with vermiculite. As long as the glowing steel doesn't come in direct contact with the insulation or the box there shouldn't be a problem. You could do that with kaowool as well. Personally I think coating in refractory is overkill for something like this. I just use a steel 5 gallon bucket (with a removable lid) filled with perlite for this purpose.

Interesting. Usually you see plate quenching with high carbon stainless alloys. As I understand it, the reason is mainly because those alloys need long ramp and soak times that could change the carbon content of the steel if open to the air. Generally these are heated in stainless steel pouches to keep the oxygen from the steel and then plate quenched assisted by air blast from a compressor or something similar. The reasons for plate quenching rather than oil quenching have to do with the finish of the blank and the time it takes to remove the blank from the stainless foil pouch. This seems to be an attempt to avoid warping during an oil quench more than the plate playing a large role in dropping the temperature quickly. If that's the case I wonder if using some heavy expanded metal or something similar might even be better. If I'm quenching a thin blade I will sometimes set up a couple pieces of angle iron in the jaws of a vise so I can slide the blank into place immediately after quenching, tighten the vice and then add a couple c clamps on the ends. Of course I don't know for sure if the blades would have warped or not, but this does seem to keep it to a minimum. Distal tapers running in both directions from the ricasso area complicate things though.

There are a couple potential issues. Yes, you definitely need somewhere for the exhaust gases to escape, but there are other things as well. When you say you want to use it for heat treating, what exactly do you mean? If you want to temper with the system you will find it to be a challenge. The issue will be keeping the temperature low enough. For most gas fueled forges, it is almost impossible to use the same burner to stay at tempering temperatures and also be able to hit quench temperatures or forge welding heat. If you are just planning to use it to reach and hold quench temperatures you can make something like this work. However, you can see in the video when the solenoid kicks off and only the bypass is active, the flame color changes to a purple hue and the flames lift off the burner head. This is because the air supply has not changed at all, but the fuel has. During those times there is an extremely lean flame, which means excess oxygen is entering the forge. That can lead to scale formation inside the forge, and could inhibit forge welding, especially if welding without flux. On the other hand, it does not appear as though he controls the temperature of the forge with the PID when forge welding, so that may not be much of an issue. There are a few ways around the oxidizing flame issue. The easiest is to use a naturally aspirated burner which pulls in the right amount of air with the gas across its entire effective operating range. That way you just need a single solenoid for the gas, and of course a bypass line for the gas like he shows. Since you don't use electricity to aid combustion with a fan, you don't need to worry about the power going out. If the power goes out the solenoid will close and the burner will continue to run on the bypass setting. For a forced air burner there are a couple options. One way is to have a variable speed fan with a separate circuit so that the fan slows down (but does not shut off) when the gas is reduced. Another way is to have yet another solenoid on the air supply and a bypass on the air supply like is on the fuel line so that the correct amount of air is provided on the bypass line for the air to correspond with the gas bypass circuit. You would activate the 2 solenoids with the same control on the PID so that when the gas solenoid is fully open the air solenoid would be fully open as well. Unfortunately, normally closed solenoids in the 2" or larger diameter tend to be pricey. Of course if you aren't concerned with the short bursts of oxidizing flames, you can build as he shows and have a fairly stable fluctuation in temperature probably across a roughly 1300 and 2000 degrees F range, depending on your burner and forge. I have built an electric oven for heat treating. There are some advantages and disadvantages to both. With the electric oven I can temper if I choose to do so. I could even warm dinner without burning it. It can reach about 2000 degrees F as well. Once up to temperature, the fluctuation of temperature is something like 5 degrees as long as the door stays shut. The down side is it takes a long time to reach high temperatures - about 3 hours to hit 1950 degrees F. I built it to run on 110v though, and it would probably cut the time significantly if I was running on 220v at higher amps. It also takes a long time to cool down - half a day or more. With a gas forge I'd expect to see 2000 degrees F in a half hour or less.

For the price they are charging here it's definitely worth it to make your own. I used a piece of barbell for the hammer. It already had a knurled section to aid in getting a good grip. I had a length of thin walled tubing with the needed diameter that was reduced on one end so that it could be nested inside another piece of tubing. After inserting the barbell into the tubing on the reduced end I ran a bead of weld around barbell that protruded from the other end. That prevents the hammer from being removed from the tubing. Lastly I ground a portion of some solid round stock to the right diameter, inserted it into the larger end of the tubing and welded it in place. I used short section I cut off an S cam from a semi trailer, but any medium carbon steel should work fine for the anvil side of the tool. However, there is another alternative that is already closer to what you want. Do a search for "Slide Hammer Tire Bead Breaker." Those tend to be more reasonably priced, longer, and heavier than the slide hammer like the one you showed above. All you would have to do is replace or reshape the end of the tool.