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About the2ndcashboy

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    Livingston, Tx

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  1. My NARB would run at 5psi for about 30 minutes and then start popping. At first I turned the gas up, and that worked, but then I got smart and just opened the doors up all the way. Now it runs @ 5psi for hours at a time, at a nice yellow heat.
  2. Yes, I've already signed up with littleblacksmith for a class this fall. I might check into Lyle Wynn as well. I grew up in the county Brazeal is based in, and still have family there. Wynn is in that general area as well.
  3. Ah ok, so he's still in Kenya eh? I noticed one of his pages said he was going there late last year, but there was no timeline.
  4. Is Brazeal still doing classes? Everything I can find on the internet is outdated, and I emailed him with no response. Is he ok? I haven't heard that anything happened to him.
  5. I don't think I'd want to use Matrikote as a finish coat over fiber in a forge. At least not anywhere that might get bumped or poked. I suppose you could do a hard floor of some sort and then coat the rest with matrikote.
  6. Sounds good. Do you have a schedule for the classes yet? I'm interested in hammer and tool making.
  7. So I've been lurking for awhile. And finally started posting a few weeks ago. Perfect time for an introduction, right? I'm an aircraft sheetmetal/structures tech by trade, and a rank newbie at blacksmithing. Got started doing stock removal knives 10-15 years ago. Made a few off and on over the years, then finally made my first forge 2 years ago to heat treat some steel. It was just a brick charcoal forge, but I discovered I really enjoyed forging. After a hiatus to remodel/sell our house in the suburbs and then buy a house/farm out in the boonies and get that up and running, I finally got the project list worked down far enough so I can start into blacksmithing in earnest. Put together a nice gas forge last week and am getting my work area squared away. Haven't made much other than some leaves out of 1/2" stock so far. I'm really looking forward to learning the craft. I've spent my first 35 years trying out a huge variety of different hobbies (mostly involving metalworking), and I think it's time to settle down and really dig deep into something. IFI seems like a good place to hang out and learn.
  8. I just hope the data I got is helpful to people, even though I should have done quite a bit more "before" testing I think. I may make a smaller knifemaking specific forge sometime this year using the same materials and a 1/2" NARB. I'll do more "before" testing if so.
  9. I don't know what Wayne's castable #1 & #2 are, but I used Mizzou in my burner. It's what the ribbon burner plans floating around out there recommend. Supposedly Kastolite isn't tough enough, but I think it's what Frosty used in the original NARB (strengthened somewhat). Seems to me the expanded metal on the edges is almost required in these smaller size burners. There's just not enough room for a decent lip on the cutout and 3 rows of holes. My mold was 2x2x7, and 2lbs of mizzou was pretty much exactly enough to fill it. I used the mixing instructions from Hard Luck Forge. I've fired it to full temp a half dozen times so far and it seems to be holding up well. There's one hairline crack across the face but it's only about 1/4" deep. I used an old toaster oven for the initial heating/crayon melting. Just took it to 250, 350, and 450 for an hour each (cooling between each cook) after letting it air cure for 24 hours. As far as buying the refractory in larger amounts, it's probably not worthwhile to get a whole 55lb bag of mizzou unless you're going to line some forges with it too. At 2lbs a pop, that's a LOT of burners. Hard Luck sells mizzou in 5, 10, and 20lb bags. A 5lber would do 2 NARBs. In your case, I'd say most of your issues came from mixing refractories, rather than the amount of water you added. Different castables will have different heating and expansion rates. You might get away with doing that on, say, a forge liner that's only 1/4" - 1/2" thick. A 2" thick block is gonna have problems.
  10. I ran the test again today, just to see if the coating reacted any differently on the 2nd firing. The warm up curve was much more uniform this time. No weird pauses or anything. Actually tracked pretty closely to the uncoated test, with the exception that it was still climbing at the 10 minute mark, and the liner itself was obviously not heating up as quickly. It was still about 2175f @ 14 minutes though. I took the TC out at that point and let it run to 20 minutes, then put it back in and let the temp stabilize. It was at 2280f when I took the TC back out @ 22 minutes and put the stock in for the timed heat. The liner looked like it was pretty close to uniformly high yellow heat, so I hoped the stock would heat much quicker this time. It took right at 4 minutes this time, which is much better than the first coated test, but still not as good as the uncoated. I'm thinking I'll have to run the forge for a good 30 minutes to get the liner to full heat soak, and that would probably get it to heat the stock the same as the uncoated. That's kind of disappointing. I've always heard that the kiln wash will drastically cut stock heating times, but I didn't get that result at all. My guess is that the people that had the large heating improvement either didn't have a layer of castable over the wool, or were heating to a lower temperature. Or both. The stuff really does provide an insulating effect, but that may actually be somewhat counterproductive in a forge with a decent heat mass like mine, at least in short forging sessions. After I finished the stock heating test, I turned the burner down to 6-7psi to see how long it would run without backfiring. After about 10 minutes it was still running fine, so I stuck the TC in to see what the temp was. It very quickly ran up over 2300f , so I snatched that thing right back out of there. Good to know it will run that hot even lower than 10psi. I'm excited to see what it does once I get the doors done and the burner mounted properly. Overall, I'd say the Matrikote was probably a good addition. It definitely increased the overall temp. It also should make the lining more durable, and with its increased insulating effect, I should be able to run the burner lower without backfiring. I do wish I'd done some more testing with the uncoated forge first though. If I had it to do over, I'd have tested the uncoated forge at more of a variety of burner psi levels, so I'd have more points of comparison with it now that its coated. I wasn't expecting the poor stock heating results after coating. I was aiming more to check the max temps and warmup rate. The stock heating test threw me for a loop.
  11. This was the first firing with the Matrikote. From my understanding, there's not really a burn in process like refractory. I can stick the TC in next time I fire it up and see if anything changes. I'm definitely going to try the stock heating test again, probably after the forge has had more time to heat soak. It probably would have been better to run the uncoated test a bit longer, but I was fairly confident it had stopped climbing. Uncoated, the temperature rise was fairly consistent, it didn't really "pause", just climbed steadily until it stopped around the 9:30 mark. Coated, there were several points where it stopped climbing. Especially once it hit about 1900 the rate slowed way down. It hit 1900 @ 5, and then actually dropped a couple degrees before it started climbing again @ 6 minutes. I let it run past 10 minutes because of that, and because the forge still hadn't reached that bright yellow that it had uncoated.
  12. I made a new thread with my testing results. Does the Matrikote make the forge better? Sort of!
  13. So we had some discussion in the NARB thread about whether a kiln wash like Plistix or Matrikote would actually increase the max temp of a forge, or just make it heat stock quicker. I just built my first gas forge using a NARB, so it seemed like a good time to get some solid numbers, instead of subjective color heat reading. I'll start with the forge specs: I built it in a 20# propane sized bottle. Two 1" layers of wool, ridgidized and then coated with ~3/8" of refractory (Plibrico Hyrezist 2700, best I can tell its somewhere between Mizzou and Kastolite 27). I haven't made a slider for the brick doors yet, so for now I've been blocking about 3/5ths of the opening (4" high by 7" wide) with a fire brick. Burner is a 3/4" inducer NARB. I'd run the forge a couple times, and even semi-successfully forge welded, so I knew it was getting good and hot. I purchased a PID and type K thermocouple so I could get actual temperature readings throughout the test. Matrikote was painted onto the lining, ribbon burner flame face, and the flame side of the brick I used to partially block the opening. TC was inserted through the front, and extended about halfway to the back, directly under the burner (not ideal placement, but its a ribbon, most of the forge is directly under the burner). 1st test (no Matrikote): Cold (80*F) start @ 5psi 2 minutes @ 5psi and it was @ 1500F. Forge was just starting to glow. TC was probably mostly heated by direct flame. At that point, I turned it up to 10psi and let it run. 5 minutes @ 1750F 8 minutes @ 1900F (forge is a nice high orange/ low yellow 9 minutes @ 2000F 10 minutes @ 2040 The temperature basically plateaued at 9 minutes, and had pretty much stopped climbing completely by 10 minutes. I thought about cranking it up to max (20psi) but I didn't want to damage the TC before I had a chance to try the Matrikote. K-type TCs are rated up to 2300f, but I don't think it would live long in a flame at that temp. I waited til about 15 minutes and put in a block of cold-rolled steel measuring 2"x1.5"x1.5". Colors are somewhat subjective, but it was fully up to temp at around the 3:30 mark (bright yellow heat). 2nd test (after Matrikote): Cold (82*F) start @ 5psi 1 minute @ 1500F 2 minutes @ 1680F. Increased burner to 10psi and let it run. 3 minutes @ 1750F. Spots are starting to glow in forge lining, but majority of lining is not glowing even dull red. 5 minutes @ 1900F. Entire lining is starting to glow. Some spots are bright, others still dull. 8 minutes @ 2000F (temperature stopped climbing between 5-6 minutes, then slowly started climbing again) 9 minutes @ 2035F 10 minutes @ 2060F. At this point the temp was still slowly climbing, and the forge interior still wasn't glowing uniformly yellow, so I let it continue running. 14 minutes @ 2190F. Somewhere around the 13:30 mark it stopped climbing. Forge interior is almost uniformly glowing. I then put in the block of steel and timed how long it took to reach temp. It reached a uniform yellow around the 5:30 mark. Conclusions: The Matrikote seemed to reflect the flame heat very well. Temps came up much quicker, until about the 1800F mark, after which it slowed down considerably, to the point where at 10 minutes, the before/after temps were roughly equal. The forge lining heated up much slower with the matrikote. I ran it for about 20 minutes total, and the lining wasn't totally uniform until the last several minutes. Max temperature increased by 150F, but took an extra 4 minutes or so to reach. The real surprise was the stock heating test. I've always heard plistix/Matrikote will heat stock much quicker, but instead it took considerably longer. I actually took it out of the forge briefly around the 4:30 mark, because I was sure I just wasn't seeing the color properly. It was only yellow on the corners and edges, the center was still orange. It took another minute to heat fully. I'm really not sure what to make of that. In hindsight, it would have been useful to leave the TC in the forge while heating the stock. The lining may not have had as much stored heat due to the better insulation of the Matrikote, and therefore the forge temp dropped more after the stock was put in, so if I ran the same test after, say, 30 minutes, the stock might heat quicker (although I couldn't really see a "cold" spot around the stock, so I dunno). Alternatively, the Matrikote may be insulating both ways, and blocking some radiant heat from the lining. At a lower temp, the flame would heat the stock quicker than the forge lining would, so you might get a different result. I also suspect a forge without a refractory layer over the wool would gain much more from the application of Matrikote than mine did, since they have very little thermal mass to begin with. Overall, the Matrikote was probably a good addition, but I would have liked to see a better result on the stock heating test. I'm pretty happy about the increased max temp though. I should be able to forge weld at 10psi easily. Especially once I finish the brick doors on the front and get the burner properly mounted and insulated. Once again, I'd like to thank Frosty for the NARB development and plans. The thing runs great
  14. I don't have the burner properly mounted yet, so there's a little hot gas leakage around it. Whenever I permanently mount it on the forge, I'll pack wool around it, that might help keep it a little cooler. Its possible that it's just something inherent to the design though. There should be a balance point where the cooling effect of the fuel/air mix can no longer counteract the heat soaking from the chamber. That balance point will change for each forge though, depending on insulation and size. Fir mine, it might be lower than 5psi, since I had it hotter and then turned it down after it was already heat soaked. If I started out at 5 and stayed there it might be ok for quite a bit longer. Maybe after I finish this round of testing I'll do another. Do a cold startup at 2psi and see how long it takes to get to temp, what that temp is, and if/when it starts woofing. Then crank it to 5 and see what happens. It's really not critical though, since I'll probably end up doing most of my forging around 10psi anyway. It just might be nice to be able to burn it lower for heat treating purposes.
  15. Round one of testing is complete. I ran the forge at 5psi for 2 minutes and was at 1500f (I think it was mostly just direct flame heating, the forge wasnt really hot yet). I then cranked it up to 10psi and hit 1750f at 5 minutes, 1900f at 8 minutes, 2000 at 9 minutes, and 2040 at 10 minutes. I stopped making notes at that point because it basically plateaued between 9 and 10 minutes. I didn't go up higher than 10psi because I didn't want to burn the thermocouple before I got a chance to test the Matrikote. 2040f is dang near welding temp anyway, I'm stoked that it does that at only 10psi. I also put in a 2"x1.5"x1.5" block of cold rolled to see how long it would take to come up to temp. It's a little subjective, but I'd say it was up to a nice yellow heat by 3:30. I would also note that after 20 minutes at 10psi, I turned it down to 5psi and did a little forging. It started "woofing" after about 10 minutes at 5psi. Turned it back up to 10psi and it was fine. I'm going to paint the flame face of the burner with the matrikote and see if it makes any difference there as well. I'll paint the forge interior with Matrikote tomorrow morning and then hopefully do the "after" testing on Saturday sometime. Maybe I should make a new thread with the complete results? I don't want to clutter up this thread too badly.