Dewnmoutain Posted December 8, 2020 Share Posted December 8, 2020 So, how do i forge weld? Hopefully i made you chuckle. But seriously though, i do have a non traditional forge welding question. When you heat up the metal to welding temp, and then hit the metals together to set the weld, how thick is the weld supposed to be? And how thick does the weld get with subsequent heatings? I included a picture to hopefully convey what i am asking about. Theres a third and fourth question im sure i should ask, but cant figure out how to ask it, but it relates to the drawings on the bottom of the picture. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted December 8, 2020 Share Posted December 8, 2020 Don't feel bad, I can't figure out how to answer. Quote Link to comment Share on other sites More sharing options...
George N. M. Posted December 8, 2020 Share Posted December 8, 2020 Dewn: If you are welding two pieces together with the same composition the metal of one is fuzed with the other and flows into each other seamlessly. So, there is no depth to the weld except the total thickness of the 2 welded pieces. In that sense, forge welding is kind of like casting. It is not lie a glued joint where there is a thickness to the joint which is filled with glue or an arc or gas weld where you are adding material which penetrates some distance into the metal being welded. If you are welding dissimilar steels together, e.g. a low and a high carbon pieces, the carbon content will extend some small distance into the other piece but not very far, I would guess a few millimeters at most. That said, the crystal structure of the steel may be different than the unwelded portion but it would take detailed metallurical an microscopic analysis to determine that. "By hammer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
Dewnmoutain Posted December 8, 2020 Author Share Posted December 8, 2020 So i understand, cuz im practicing with mild steel (im a glutton for punishment, i know), the unit becomes one hemogeneous piece? Quote Link to comment Share on other sites More sharing options...
George N. M. Posted December 8, 2020 Share Posted December 8, 2020 Yes, except for some possible change in crystal structure at the weld site it should be homogeneous throughout. With mild steel there would be less crystal change than in something with higher carbon content although there might be a change in crystal size. "By hammer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
Frazer Posted December 8, 2020 Share Posted December 8, 2020 I think your primary question has already been answered, I just want to add one other thing. If what you would like to do is obtain a single 3/8" bar you will have to upset the ends of the bar and scarf the sides that will be welded together. I could go into why, but Mark Aspery has a video called scarf theory which explains and demonstrates how this works much better than I can. In the pictures you show, if you try to weld two pieces like this: what you will end up with is closest to this: Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 8, 2020 Share Posted December 8, 2020 Forge welding is an example of solid phase welding; as mentioned in the perfect weld there would be no evidence of it when using the same alloy for both sides. In the real world you often can see a line of inclusions or slight alloying effects due to fluxes used; or if high carbon steels were used there may be a thin layer of decarburized steel created. Using differing alloys; then you also get diffusion of various alloying elements in both directions. Carbon being the drag racer of elements can diffuse quite fast and deep and it has been shown that in thin layers the carbon content may equalize after a mere 4 times to welding temps. Other alloying elements are so much slower to diffuse they may show little to no movement. Diffusion depends on the time, temperature and element(s) involved. May I commend to your attention "The Solid Phase Welding of Metals", Tylecote). Quote Link to comment Share on other sites More sharing options...
Dewnmoutain Posted December 8, 2020 Author Share Posted December 8, 2020 Quote Link to comment Share on other sites More sharing options...
Dewnmoutain Posted December 8, 2020 Author Share Posted December 8, 2020 (took too long in writing this up and lost the window to perform an edit for one post.) This is another one of those "im not sure how to ask this, so bear with me please" kind of posts. Working in the shop, practicing some forge welding, and i kept running into this issue where the metal would stick together, but when I'd test it, it would fail, just snap off. And i had seen this happen earlier in my attempts, and at those earlier attempts i thought it was due to my inexperience, i was forgetting something, too much scale, etc, just messing up my weld attempts. Today though, i took my time, i made sure the metal was clean, i fluxed the proper amount, all the necessary steps, and it just failed. I did a test to see if the weld was holding, and it failed. So this made me mad. Like real mad. after i calmed down, I thought id perform a test to see what's up, make an educated guess, and post on here to see if i am correct with my idea, or if one of you knowledgeable smiths could help answer my question. I took 2 pieces of 3/8s square stock, cleaned the ends where the forge weld was going to be, added some light flux, tossed into the fire. I brought them up to the forge weld heat, rubbed them together to see if it was at the weld heat, which it was cuz they stuck together, kept them in the heat for a slow 10 count, pulled out, and did some light hammer blows to set the weld. Back into the fire, brought back to heat, repeat. did this for a total of 3 times. The end result was picture #1. (i dont know why it's ordered 2, 1, 3, 4...) the white line on the steel is the approx end of where i stopped forge welding. i took an angle grinder, and cut off about 3/4" from the tip, as shown in picture #2. picture #3 shows the longer piece of steel as being forge welded. picture #4 shows the same forge weld, from a different angle. picture #5 is showing how much weld, by way of the white line on the vise, was left over for the test i was about to perform. I was a bit off with my guestimation as shown in #6. For picture #6, what i had done is clamped one of the bars in the vise, and i took my tongs, gripped the top bar, and pulled towards me. This caused the metal to shear away from the other piece. It took a bit of effort to snap this piece off, but it did come off. And it parted at the weld junction. Looking at the metal, as shown in the picture, it shows a nub of discolored metal from where the weld was set, and the rest of the bar was unaffected, or had scale built up on it. So, i performed the same test to see what would happen with my fully forge welded piece. Picture #7 shows the full cut off 3/4" piece forge welded piece, but intentionally twisted to failure. I had to cut a shallow groove in the piece at the seam to induce a critical failure, as shown by the ground marks on the metal. Even with that thought, it took some serious grunting and leverage to get that small piece of metal to snap. But, looking at the end result, it also has that same distinct color as shown in picture #6 at the end. So my questions that i am having a hard time answering are "are these pieces actually forge welded together?" "are they not?" "am i doing a wrong test to determine if it's forge welded?" "am i overthinking this?" Quote Link to comment Share on other sites More sharing options...
Frazer Posted December 8, 2020 Share Posted December 8, 2020 It appears to me that you have successfully tack welded the two together, which I would consider to be the hard part. All you have to do from there is refine the weld by bringing the joint up to welding heat a few more times and fuse (aka whack) the two together some more. primarily in the welding plane, and a little on the sides to clean that up as you go. You can tell just by looking at that seam that the two bars are just barely fused together. Once that seam is closed up (pretty much disappears) and you work the two together some more you should have a nice strong weld. Keep in mind that in order to to get a good strong weld you are going to sacrifice some of your width in refining the weld. It can be frustrating, but the way I see it you're already most of the way there! I'm sure someone else will have more to add. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 8, 2020 Share Posted December 8, 2020 Are you scarfing the pieces gently, [)(], before welding to make sure the centers meet first pushing any crud out of the weld? Quote Link to comment Share on other sites More sharing options...
Dewnmoutain Posted December 9, 2020 Author Share Posted December 9, 2020 6 hours ago, Frazer said: It appears to me that you have successfully tack welded the two together, Ahhhhhhhhhhhhhhhh! I get it now. 5 hours ago, ThomasPowers said: Are you scarfing the pieces gently, [)(], before welding to make sure the centers meet first pushing any crud out of the weld? ...no. i was practicing just getting them to connect first. I probably shouldve been taking the extra minute to set up that scarf on the material Quote Link to comment Share on other sites More sharing options...
Frazer Posted December 9, 2020 Share Posted December 9, 2020 Good luck my good sir. Quote Link to comment Share on other sites More sharing options...
pnut Posted December 9, 2020 Share Posted December 9, 2020 Mark Aspery has a good video titled "scarf theory' you might want to check out. You may have already viewed it as your first illustration looks like the ones used in the tutorial. Here's a link to save you the time having to search for it. https://www.youtube.com/embed/ucfZIjAdXwM?autoplay=1&FORM=VIRE2&PC=OPALAND Pnut Quote Link to comment Share on other sites More sharing options...
Frazer Posted December 9, 2020 Share Posted December 9, 2020 Haha beat you to it pnut I do enjoy that video. Provides great visuals and explanations. My only complaint is that he makes it look too easy.. Quote Link to comment Share on other sites More sharing options...
Dewnmoutain Posted December 9, 2020 Author Share Posted December 9, 2020 24 minutes ago, Frazer said: Haha beat you to it pnut I do enjoy that video. Provides great visuals and explanations. My only complaint is that he makes it look too easy.. The thing that was missing for me to fully understand was that bit you talked about in your previous post, about working it down to remove the seam, and loosing height in your material because your having to mold the material. I watched asperys videos several times already, and always felt like there was something missing. Finally Frazers comment got me what i was missing. So tomorrow i should have some good welds completed. Quote Link to comment Share on other sites More sharing options...
pnut Posted December 9, 2020 Share Posted December 9, 2020 Glad you had the ah-ha moment. I do love that moment of epiphany when the last piece slides into place. Keep us posted. Pnut Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 9, 2020 Share Posted December 9, 2020 When having issues; going back to first principles seems to help. The better you get the more you can "cheat". I've seen Billy Merritt weld at temps I would consider on the cold side for forging! Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted December 10, 2020 Share Posted December 10, 2020 19 hours ago, Frazer said: he makes it look too easy. It is once the light bulb goes on and a lot of practice. Quote Link to comment Share on other sites More sharing options...
Dewnmoutain Posted December 11, 2020 Author Share Posted December 11, 2020 Getting better. Quote Link to comment Share on other sites More sharing options...
Frazer Posted December 11, 2020 Share Posted December 11, 2020 On 12/9/2020 at 7:16 PM, Irondragon ForgeClay Works said: lot of practice If I can forge things half as smooth and clean as Mr. Aspery in my lifetime, I'll be content. He was supposed to come to Rochester before CV shut everything down.. I believe it was canceled as a result.. Dewnmountain, looking good! Quote Link to comment Share on other sites More sharing options...
anvil Posted December 11, 2020 Share Posted December 11, 2020 There is a good chance that you will be able to do that right after your next forgeweld. Quote Link to comment Share on other sites More sharing options...
Shabumi Posted December 11, 2020 Share Posted December 11, 2020 5 hours ago, Frazer said: If I can forge things half as smooth and clean as Mr. Aspery in my lifetime, I'll be content. I was in a forge welding class with him in February. One of the tips he gave the class was to be proficient in forge welding you need to do 1000 welds, but that includes the failures as well as the successes. Quote Link to comment Share on other sites More sharing options...
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