Blue Duck Forge

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  1. Blue Duck Forge

    What advice would you give to you?

    Definitely this. I missed around 20 years of opportunity to learn (and much better equipment prices) because I grossly overestimated cost and difficulty of forge construction, and didn't know where to learn otherwise. A break drum forge is a highly efficient means of wasting charcoal. Poor results on my first anvil (80lb clevis) were limitations of skill and not the anvil. Stick with the chunk-o-steel anvil for a while, but buy a real post vice ASAP. Being cheap (scrounging / DIY) usually costs more money in the long run than buying the tool/material that I needed. Being cheap almost always costs more time.
  2. Blue Duck Forge

    Cool historical Blacksmith gear

    If you'll type "scythe peening anvil" into your favorite search engine and look at images, you will find 3 general types. One is a more modern design with a cap that fits over a central cylinder; we'll ignore that one for this discussion. The other two types are either flat top (often a slight radius) or a fuller shape. The hammer used is the opposite of the anvil - cross-peen on flat or flat on fuller (think "peen"). You will notice on the taller anvils that the spike sometimes has cross-pieces a little ways up from the bottom. These cross pieces provide a stop when using the anvil in the dirt between one's legs. The short anvils are driven into a stump or peening bench.
  3. Blue Duck Forge

    Cool historical Blacksmith gear

    I'm not saying it isn't a nail making bench, but it looks just like a scythe peening bench, too. http://wrenwoodmeadow.blogspot.com/2016/08/haymaking-2016-good-to-see-meadow.html?m=1
  4. Blue Duck Forge

    attention all metalurgy ...

    Thank you SLAG for expanding on the topic. I was getting frustrated with the forum software and trying to post small bits quickly enough for my posts to merge, and I can see looking back that I did not adequately discuss dense and adherent vs. spalliing (and/or non-dense) oxides. Your real world example, in particular, brings this seemingly obscure topic to life.
  5. Blue Duck Forge

    attention all metalurgy ...

    Well, posting little bits at a time seems to work, but one bit got eaten... -another exception is forming dense, adherent (and protective) oxide scales like chrome oxide on stainless steel vs. rust (which spalls - falls off) on steel or forming different oxides (Fe3O4 vs. Fe2O3, for example) . Ugh, good enough for now I hope . Please let me know if I didn't explain everything well, but my posts are being eaten and I cannot even report them without errors.
  6. Blue Duck Forge

    attention all metalurgy ...

    Can't post - trying to edit this. Sorry. The more understandable version is that for a specific material composition in a particular phase (i. e., steel in Austenite vs. ferrite vs. Martensite phases) the oxidation rate (as measured by the total weight increase of the sample) will increase at a predictable rate for that given phase as temperature increases. Sorry Some things that cause exceptions to the predictably of the oxidation rate for a material of a specific chemical composition include: -passing through a phase transition (ex. steel changing to the Austenite phase as it reaches the critical temperature - this is where it becomes non magnetic), -things like dislocations (something shifted relative to where it should be) , vacancies (holes in the crystal structure) , inclusions (something that doesn't generally belong where it is) , strain (stretching, compression , or other change in the relative distance or orientation between the atoms in the crystal structure), or other things which can impact diffusion rates. This can be measured with a sensitive scale in a controlled atmosphere furnace called a TGA.
  7. Blue Duck Forge

    attention all metalurgy ...

    Oxidation kinetics is diffusion driven, and samples oxidized at various temperatures will plot as a straight line on a log-log plot of time and weight gain (all samples oxidized at a given temperature will be at approximately the same point). Extrapolation along the line is extremely accurate in predicting oxidation kinetics at any temperature between the maximum and minimum. Any kink in the plot between straight line segments of different slopes indicates a temperature at which the diffusion rate changes, whether due to a phase change, oxide spallation, or some other mechanism. What wasn't clearly defined in the article was whether the grain boundaries were of a separate phase than the grains themselves (i.e., grain boundary carbides or similar), or whether the mismatch between the crystal lattices at the boundaries (or just a concentration gradient causing lattice deformation) is responsible for the significant increase in diffusion rate. Interesting either way. This is easily investigated with a TGA (thermo gravimetric analysis), in case anyone is in college and has interest in this or related topics. (A note for posterity: the above is evidence of a misspent youth if there ever was such.)
  8. Blue Duck Forge

    using aero engine bolts

    I have seen several kinds of steel, Inconel (usually 718), and Ti-6Al-4V bolts used in aircraft engines. I say try a spark test as BGD suggests. As for the steels, many were 180-220 ksi (and sometimes allowed for bolts from a list of compositions heat treated accordingly), but sometimes more or less. If you end up with a cut off from one of your projects, a quench test could be revealing.
  9. What part of Florida are you in? Anvil prices vary considerably in the couple of areas that I had been watching before I got a reasonable anvil. If you are close to me, I would like to look at it, but would only be willing to meet you somewhere in between your prices from what I can see. 

  10. Blue Duck Forge

    Just starting blacksmithing

    http://victortechnologies.com/IM_Uploads/DocLib_7465_2102A_Stoody_HardfacingHighAlloyCatalog.pdf Look at the charts that the manufacturer provides when selecting rods or wire. You won't be happy with the results for the cost of using the Stoody 1105. "Applications: Non-lubricated metal-to-metal rolling or sliding parts where temperature can be a factor such as steel mill rolls and undercarriage parts of earth moving equipment." The abrasion resistance AND impact strength are listed as "low" (relative values) for this rod. You want one with a longer black line on the above chart.
  11. Blue Duck Forge

    Fire and charcoal management

    Some of it was hardwood chunks, and some of it looked like hardwood floor cutoffs. I also found a few small chunks of what I interpreted as refractory from the kiln. I did save the best of the clinkers, as it was almost like glass (with rocky chunks stuck in it).
  12. Blue Duck Forge

    Fire and charcoal management

    As you may have already determined from Mr. Stevens' description above, dirty charcoal will make clinkers. My first 32 lbs. bag of lump charcoal left several shiny green-grey clinkers (color after cooling).
  13. Blue Duck Forge

    Custom Yari Spear / Bo staff

    Rockstar, Latticino and Frosty nailed it. The shear forces between plys make impact hard on composites. I don't know much about composites with a one-part thermoset matrix, but I could see how phenolic would be a good one. I always regret it when I mess up a metalographic mount and have to break my sample back out when I use the phenolic. Some of the newer composites use thermoplastics like PEEK as well, so the fiber and matrix could likely be tailored to the application. I really like Mr. Stevens' idea with the bamboo. I have been wanting to plate some bamboo with the stuff in the links below (with an appropriate intermediate material layer for adhesion) for staves and bicycle frames. http://www.integran.com/services/plating-on-composites/ http://www.integran.com/products/ultra-lightweight-structural-parts/
  14. Blue Duck Forge

    Custom Yari Spear / Bo staff

    Carbon fiber composites tend to have poor damage tolerance, particularly due to impact. The below article discusses the findings from a workshop with respect to the damage tolerance of carbon fiber reinforced composites in 1986 (i.e.,after the carbon fiber reinforced composite components in 4th gen. tactical aircraft were designed). I have included a relevant quote. http://www.sciencedirect.com/science/article/pii/0263822386900255 " The main conclusions to be drawn from the workshop are: (1) damage from impact is the worst type of damage for these materials—significant reductions in the compressive strength will occur following impact; " Please also consider the application of carbon fiber in road bicycles. If they didn't tend to fail so catastrophically (and somewhat unpredictably) after relatively minor wrecks, many more cyclists would use them (My cycling nut best friend included).
  15. Hi Riley. I took a job a couple hours south of here, and will therefore be moving. I have a number of items that I want to offer to you before I just leave them on the curb. I had collected a couple of break drums/disks, old grills for forge carts, and assorted scrap steel and aluminum. I also have a heavy layout table. If you have need of any of these things, please let me know and I will arrange to give them to you. 

    Chris