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Dan Hertzson

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Everything posted by Dan Hertzson

  1. Caveat: Just keep it out of the direct flame from the burner if you want your thermocouple to last
  2. If your forge hasn't cured completely yet, and from your description it most likely hasn't, you will be driving off moisture from the castable for a while yet. The steam created will definitely heat up the forge skin and may even interfere with a stable flame. Unless you want the castable to crack, you need to heat it very gradually. You might even want to drill a small hole in the bottom of the skin as a "weep" for the steam generated. I would switch the locations of the needle valve and ball valve in your gas train assembly. Ball valve is for quick emergency shutoff, needle i
  3. I, and a number of other makers, have been pretty happy with using Matt Parkinson's hardness testing chisel sets. I'm sure they don't give the level of accuracy of a professional machine, but on a budget they are good enough for my purposes and can be used directly on a blade edge (and certainly out perform the off brand hardness files).
  4. Another cheap option, if you don't mind plastic piping, is to use a 3 port 2" swimming pool diverter valve. This will proportion the air between the two paths with operation of only one handle:
  5. Blower specs seem unusual. 85 CFM appears a little light for the size block you have, but 150 mbar equates to 60" WG, which is some serious overkill. It really all depends on the actual shape of the fan curve, which is not predictable from a single point of operation (if the data given is even accurate, you need the airflow at a certain total static pressure). 850W is around 1 HP, which should be plenty, so hopefully the curve matches your installation. Not a huge fan of the blue plastic elbows near a forge, or the gas hose on the ground. I'm sure that will be addressed when y
  6. When I moved my little hammer I rented both a trailer and truck from U-haul. Worked quite well for me.
  7. Well, I don't know about double quenching as a valuable addition to a heat treatment regime if it is defined as simply bringing the steel above the transition temperature then rapidly cooling it and repeating that exact process again. However I have had a teacher I respect greatly advocate a method using two quenches to produce something that could be termed "grain refinement". As I understand it the theory goes something like this: After forging and rough grinding the blade, the grain sizes throughout can be highly irregular. A standard normalizing and stress relief heat treatment
  8. While the guard looks to fit the projected handle size quite well, aesthetically it appears to be a bit large for the size of blade (particularly the top branch). I could see that one trimmed down to fit within the circle you drew on your plan. Did you sketch the guard before forging, or just freestyle it? Nice blade profile, grind and pattern.
  9. Looks like your air inlets are choked way down. These need to be adjusted for a neutral or slightly reducing flame with the burner inside the forge. Question is whether you have hard or soft firebrick for your forge body. Hardbrick forge will bleed heat like crazy and be difficult to get up to temperature. Also may be a problem with the wood 2 x 4 stand. Softbrick will eventually break under thermal cycling. Also may be a problem with the size of chamber vs the burner output. A forge chamber can be too small as well as too large. If too small, complete flame development is not possible
  10. I would test it after you weld on the 2" pipe so you can test that joint as well if you have any question on the integrity of your welds (a temporary pipe cap will cover the open end of the pipe). Brian's idea is a good one, but I would also do a soap bubble test after the entire burner is assembled using the blower itself. This is the same test I do for any piping joints in a gas train, and is pretty simple. Just mix some dish soap with water and paint liberally over the seams and pipe joints while the system is running. If you have a leak, you will see visible bubbles form.
  11. The classic method for protecting a blown burner system against a loss of power is to install a normally closed gas rated solenoid valve in the line. Attach the solenoid valve to the same power source as the blower (or even better, in line with a supply side differential pressure switch) and on blower failure the gas will shut off. Thanks for the positive feedback on my glass. I certainly miss those days.
  12. Well I have to admit, there are certain inconsistencies that make me concerned (like the statement that he has several on hand and is always making more, when I've been looking into these for a while now and never seen one exactly like his build). Still his reticence may just be unfamiliarity with the forum environment, and nothing nefarious. While I have heard of tools and anvils "disappearing" and being resold by thieves, I've not heard this for any larger equipment (power hammers, fly presses, Space Saver Grinders, treadle hammers, hydraulic presses and rolling mills). Does th
  13. I contacted him via text and got some more specifics. They do appear to be similar to the McDonald mill, but he uses a 60:1 geared motor rather than the belt drive the McDonald has. In my opinion this will give better consistent torque, but does not have the potential safety factor of a slipping belt if there is a problem. I've only seen one small photo on my phone, but I can add the following: the top roller is supported by pillow blocks. The bottom is adjustable with a large hand screw and engaged with a foot pedal. I don't think it has the hand lever ratcheting scheme the McDonald has
  14. Well, I used to blow glass. Can't afford to any longer, it is a full time occupation, not a pickup hobby (you have to keep the furnace going constantly, then turn out product to pay for the fuel costs...). Try it sometime at Corning, Pittsburgh Glass, Haystack, Penland, Pilchuck or the like once things really open up again. It's loads of fun, but watch out. It can be at least as addictive as blacksmithing. Here is a shot of one of my functional lines from back in the day:
  15. John, I certainly get that, having spent 10+ years blowing glass with a glory hole lined with untreated ceramic wool fiber. Had an MRI for a kidney stone and docs said,: "Surprise, you have significant scarring on your lungs, never been a smoker, right?". Back then nobody ever mentioned that the fibers break down with heat and time then get airborne. I'm just lucky I designed in a full enclosure for my glass furnace and glory hole, then used a 30,000 CFM exhaust fan to keep the breeze going the other way. I am a strong advocate for encapsulation as well. My current forge has 2"
  16. Blacksmith's powered rolling mills for hot steel, or hand cranked jewelers mills for rolling sheet and wire? Do you ship them from Houston, or pickup only?
  17. Another fantastic reproduction.
  18. If it is soft firebrick it won't add appreciably to the heating load inside the forge. However, reducing the inner forge volume without improving the forge liner's insulation doesn't really help. Its a basic matter of heat into the forge versus heat out. The heat entering is from the burner. Heat exiting is from the forge skin and out the door/s. Improved insulation decreases conduction through the forge liner, lowers the forge skin temperature (reducing conduction). Reducing the forge skin temperature and the surface area, reduces the amount of heat lost to the environment by convection
  19. Also, you have a very large forge. Without a power hammer, hydraulic press, rolling mill or striker you will be hard pressed to use more than 6" of heated steel at a time. Between poor insulation and oversized forge you will be using a lot of gas. At least you didn't insulate with the Plaster of Paris and sand mix that some use. Depending on vermiculite content yours may provide better insulation than that, and will certainly hold up better (though I don't know how well portland cement stands up to high heats. Great initiative though, especially with the custom temperature sens
  20. That's a non-standard motor for a grinder (likely a DC speed controlled motor taken off a treadmill)? While it appears to be rotating in the correct direction for you you will likely have a different issue with steel dust from the grinder getting into the motor's innards and frying the unit. I strongly recommend a filtered enclosure of some kind, or at least sourcing a backup for when it breaks down. The other immediate issue I have with your design has to do with the unsupported bolts that are being used to carry the platten wheels. I'm not sure how much actual grinding you hav
  21. Don't forget to purchase and use the correct type of thermocouple wire as well. Using regular copper wire can throw off your readings, Note that type R or S thermocouples are also good for forge temperatures, just stupid expensive...
  22. Nice work. I don't think there is anything wrong with your camera, the backgrounds look to be in good focus as is the guard in the detail shot. Probably more to do with setting the correct focal point or aperture to increase the depth of field or using a tripod... A better photographer might be able to give you some clear direction on how to do this with your current equipment.
  23. Just be certain they are rated for propane use. The cheap ones designed for compressed air are not suitable.
  24. I would alternately recommend 1080, 1084 or 1095 and 15N20 for pattern welding, and those simple steels for the kitchen knives. I have no idea what is available in Mexico, unfortunately, but these steels are all relatively easy to forge and heat treat.
  25. Longer burner mixing tubes will affect how much air is induced by the high speed gas flowing into the mixing tube entry. What size orifice did you drill and what pressure are you running at? Can you open the shutter you are using for the air more while it is running? Also, try opening the door a bit more. NA forges are picky about backpressure in the chamber. Most important: how far into the forge shell do the burners project? The end of the flare should be no more than 1/2" past the outer skin of the forge. Ideally there should be a thin "shelf" of forge insulatio
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