Jump to content

Dan Hertzson

  • Content count

  • Joined

  • Last visited

Community Reputation

9 Neutral

Recent Profile Visitors

438 profile views
  1. Dan Hertzson

    Portaband question

    Anneal your steel before cutting with bandsaw. Will also make it easier to grind profile and bevels.
  2. Dan Hertzson

    Box truck workshop

    I believe that Jennifer, of JLP services, an excellent smith who does onsite demos as well as production work, has a setup in a trailer. Lots of good ideas for a portable shop in her posts: https://www.iforgeiron.com/topic/47208-portable-blacksmith-shop/
  3. Dan Hertzson

    Best beginner steel

    As far as I know you won't get any hamon etching a stainless steel Pakistani sword.
  4. Dan Hertzson

    HT oven from ceramic kiln

    You have dug deeper into this than I have. Use of dataloggers is certainly helpful. I end up sitting and watching the output parameters on the controller as it goes through ramp cycles. I'm not completely sure I have my PID constants optimized, but I have gone through the process of tuning to try to get them close. As I'm sure you are aware, the thermal mass, insulating value and heating coil characteristics have a large effect on the system dynamics for a heat treat oven, and some tuning of the constants should be expected to get accurate, or even stable, operation. My old controllers are West units (I think 2050 series controls) that are fully programmable for multiple steps of ramp and soak as well as PID constants, but don't have auto-tune. I've also misplaced the manual, so struggle with setting up programs. Can't recall what cycle time I have set, but expect 2 seconds would be too short for effective operation, even with the mercury contactors I use. I do have the system choked down somewhat, so I don't overheat and burn out the coils (as I did the first time I futzed with it after repurposing the unit from a glassblowing hot pickup oven running at a maximum of 960 deg. F to a heat treat oven that reaches 1575 deg. F when necessary. I don't worry about initial overshoot since I typically wait till the oven achieves stability at the desired setpoint before I put the blades in. I have enough thermal mass in the oven that the quick opening and closing of the door doesn't effect that too much, though my top access is less effective than a side door would be at higher austenizing temperatures.
  5. Dan Hertzson

    Best beginner steel

    If the blade wasn't differentially heat treated, you are unlikely to get a real hamon just from etching (25% Ferric/75% distilled water seems to work well for me for etching). You can fake the hamone by putting a surface resist on the top half of the blade and letting the balance etch, but any knowledgeable viewer will be able to tell. Remember to bring the blade up to a good surface finish before you go to etch, as abrasion after the fact will ruin this fake hamon. Even if the blade was differentially heat treated, there are a lot of steps to get a hamon that "pops", and some types of high carbon steel are not particularly suitable. Hopefully someone with more experience with hamons will chime in with more detail. A more worrying issue is that you "don't intend to use it just as decor". Many of the Pakistani swords are not particularly well made and could be extremely dangerous to use. Please take care with any cutting exercises. Ignore if your sentence is just missing a comma after the word "it".
  6. Dan Hertzson

    HT oven from ceramic kiln

    My systems are so old that I use 1/4 DIN controllers and contactors rather than solid state relays. They are fairly robust though, got them from a liquidator, used, over 20 years ago and most are still functioning.
  7. Dan Hertzson

    HT oven from ceramic kiln

    Any decent ceramic kiln should be more than adequate for a heat treat oven for "normal" carbon steel. You will need to ensure that your power supply is correctly sized for the amperage draw the kiln will have (likely in the 30-60 amp range) and will need a contactor or SCR to interface between the controller and the kiln elements. I don't know anything about selecting SCR units other than they will usually need some kind of variable signal from the controller. The temperature controls I've wired are usually configured to control mercury contactors (which stand up better to the sometimes rapid cycling you can get with a temperature controller than conventional magnetic contactors) with "dry contacts" from the controller energizing the contactor's coil. You will also want a thermocouple and thermocouple wire to use as a sensor. I recommend type K thermocouples for normal temperature ranges involved. Good luck.
  8. Dan Hertzson

    Celtic Iron 3

    Don't know about you guys, but I see a keyed swage for the central rib in the second to last photo. Not taking away from my appreciation of Ibor's hammer skills in the least.
  9. Dan Hertzson

    Coil spring

    Possible surface decarb from overworking the steel at elevated temperatures. Might have to grind through that layer to reach hardened steel. What is the thickest crossection that you are quenching? Are you letting it fully cool down before pulling it out of the quenchant? How well calibrated is your kiln? How long does it take you to get the stock out of the kiln and into the quenchant?
  10. Dan Hertzson

    belt grinder motors and vfd uk advice required

    In my opinion making the tooling arm out of solid aluminum bar stock is a nice option. Tight clearance, that allows longitudinal movement with nominal lateral change during tightening is nice for keeping things aligned when changing plattens. As regards tensioning arms I would grade the various different systems from best to worst as follows: manual ratchet (like the TW-90), hydraulic shock style cylinder, external spring on extended pivoting arm, and enclosed spring inside telescoping arm. The last two are debatable, but I give it to the exposed spring for ease in changing overall tension and potential repair as well as less chance of getting loaded up with dust and binding. I'm also not a fan of the floating support for the tracking wheel that many such telescoping tensioning arms designs include. One last recommendation and that has to do with the difference between belt drive and direct drive systems. In my experience the latter are quieter and less prone to vibration.
  11. Are you sure it was one of the older ones? I used an older Peddinghaus that size at the New England Blacksmith school and it had the hardest face of any anvil I've ever experienced. The teachers there said that even with students whacking on it for years it hardly showed any surface damage from miss-hits (unlike other anvils in the shop). I've heard that post Ridgid takeover they aren't nearly as good.
  12. So I'm in process of selling off (and giving away) a bunch of my old hot glassworking equipment. One of the items that I'm letting go is getting a tremendous amount of interest (relatively): an 18" diameter, horizontal wet lap wheel with replaceable diamond lapping discs. I think I've got two discs with 60 grit (one more used than the other) and one at around 300 grit. The unit has around a 1/2 HP motor, single speed, but never bogged down for me while I was grinding glass anyway. I suspect it would work for flat grinding steel (probably even hardened, diamonds, right?), but don't know how long the discs might last in that kind of use, and it really isn't set up for same. If I recall discs are quire expensive to replace. I'm selling it for $850 and now thinking of replacing it with a 9" variable speed vertical disc machine with, hopefully, replacement Nielson (?) disc system. Anybody ever use anything like the glass lap to work steel? Am I being an idiot to let it go?
  13. Dan Hertzson

    Going mass market with folder

    Pretty sure he is looking for complete, assembled, folding blades to be made from his design. Not to be negative or anything, but as far as I understand the overseas manufacturers who might be willing to produce your design at an attractive price point can't always be relied on to market the product exclusively through you, and would most likely not want to tool up for such a short run. You could easily end up with knock-offs flooding the market if the design stands out or has any special merit.
  14. Dan Hertzson

    Anvil weight question.

    Recommend considering some cold chisel work
  15. Dan Hertzson

    Anvil weight question.

    Makes it easier to lug on and off the pickup truck for the anvil shoot...