Maillemaker Posted August 8, 2012 Share Posted August 8, 2012 How many welding heats do you usually take to "complete" a weld? Now, I realize that "a weld" is a vague term, so let's say that you're welding two pieces of half inch square mild steel into a straight bar, using a drop-the-tongs or equivalent method. I've been watching Mark Aspery's youtube videos on welding and scarf theory (a speedy recovery to him) and I've noticed that he usually only shows one welding heat.http://www.youtube.com/watch?v=ucfZIjAdXwM I've also seen a video by The Ironwork Shop that advocates at least three heats to strengthen and refine the weld.http://www.youtube.com/watch?v=8jZDEtmDgxI How many heats would be needed to sufficiently bond the two pieces together? Would the number of heats be different for decorative work than pieces subjected to twisting or bending forces? Quote Link to comment Share on other sites More sharing options...
Bob S Posted August 8, 2012 Share Posted August 8, 2012 how many heats is it taking you? that's what matters. Quote Link to comment Share on other sites More sharing options...
brianbrazealblacksmith Posted August 8, 2012 Share Posted August 8, 2012 The Iron Workshop is correct. To secure a weld and make it truly one piece, you need to be able to hammer the area more just like squeezing clay back together. If you don't, the pieces would rip apart if you pried on them. "Traditional" scarfs do not work very well for today's mild steel or A36. They simply do not afford enough material to truly secure the welds especially with most branch welding done today. You can prove this by testing the welds. I stopped using "traditional" scarfs a long time ago and developed the "blob weld" and "forge welded bundle" which allows me to forge the weld a lot more. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted August 8, 2012 Share Posted August 8, 2012 i don't think we can define a good weld by a number of heats taken. it may be of interest if you are new to forge welding to see with shop time and repititon that the number of heats you take has gone down as yoiu skills progressed, Brian mentioned something that to me is far more important,and that is testing of your welds. i have taken a cold chisel and drove it into the area and remember alot of my early work split right apart, i have also band sawed throiugh the weld area and found failed areas that to me looked good from the outside. i worked to see those poor welds improve and become right the more I progressed. One more thing that I believe is worthwhile in addtion to those tests is to hold the welded piece when cool near youir ear and tap it with another piece of metal. Those pieces that did not have a kind of ring to them, did not do well wth the other testing. Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 8, 2012 Share Posted August 8, 2012 This took 2 heats on each side to weld. Quote Link to comment Share on other sites More sharing options...
nuge Posted August 9, 2012 Share Posted August 9, 2012 Like that Tim. Is that some found metal? Whats the end use? Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 9, 2012 Share Posted August 9, 2012 Its just some rusty nails pulled from some lumber I salvaged. I did it because it was there. Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 9, 2012 Share Posted August 9, 2012 double post Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted August 9, 2012 Share Posted August 9, 2012 Triple post whoops Quote Link to comment Share on other sites More sharing options...
tomhw Posted August 10, 2012 Share Posted August 10, 2012 Timothy, well done- in every respect. Quote Link to comment Share on other sites More sharing options...
anvil Posted August 11, 2012 Share Posted August 11, 2012 Lol, I think just looking at the technique,hammer control etc of the two vids should answer your question. My "theory" is make your scarf as small as your skill level allows, and use as few heats as your skill level allows. The end results with any steel will, with time be a very small scarf/upset and one heat. Consider the alternative. How many times do you hear "I can't afford traditional techniques, they take too much time.". Then watch the first vid an imagine a 2' section of rail with say20 such forgewelds. Multiply that by three or more welds per union at say 3 minutes each, and you have your answer as to the proper theory. Quote Link to comment Share on other sites More sharing options...
Frank Turley Posted August 12, 2012 Share Posted August 12, 2012 I will most of the time, take multiple welding heats on a lap weld. On the half inch square, it might take me two to five heats in order to blend in any shuts. It depends on the star alignment, condition of the fire, how hard I'm hitting, and how fast I'm moving. I like to get rid of shuts, especially on ornamental pieces. A36 is a little recalcitrant compared to the old 1020 I used to buy at the steel supply. Multiple welding heats in the same place should be sweating heats (no sparks). In that way, there is less oxidation and ruination of the metal. The sparking heat indicates that you are already into the incipient burning range where uncontrolled oxygen wants to attack the metal. If your finished product looks like the rats have been chewin' on it, you've overheated it. Not a keeper. In the old Farmers' Almanacs, there were certain days for welding. I get my scarf shaping ideas from Schwarzkopf and Harcourt.* * "Plain and Ornamental Forging" Ernst Schwarzkopf "Elementary Forge Practice" Robert H. Harcourt Quote Link to comment Share on other sites More sharing options...
anvil Posted August 13, 2012 Share Posted August 13, 2012 I have just started adding boric acid to my 20 mule team borax this last year and those pesky shuts are going away like the old A36 used to do. When I discovered this, it really made me smile. :) Quote Link to comment Share on other sites More sharing options...
anvil Posted August 13, 2012 Share Posted August 13, 2012 Oops that should have been pre A36. Also the boric acid is from a local drug store. It's cheap and 100% boric acid Quote Link to comment Share on other sites More sharing options...
Frank Turley Posted August 13, 2012 Share Posted August 13, 2012 I made these hammer eye tongs the other day. The rectangular block jaws fit inside the punched eye. I forge welded on the reins, 7/16" round. Each rein took about five welding heats. On welds of this size, the anvil can be quite a heat robber. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted August 13, 2012 Share Posted August 13, 2012 Frank I do not see any welds.....Lol Nice pair of tongs,,I expect you know I will steal that design when the weather cools a tad,,Thanks .. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted August 13, 2012 Share Posted August 13, 2012 As others have stated, there is no hard and fast answer. Some years ago, I was demonstrating at a fair and was asked to do a private exhibition of forge welding for a couple of the sponsors. I made a few feet of chain (one heat per link) then donated the piece for a fund raiser and promptly forgot about it. Unbeknownst to me, they eventually took that piece of chain over to the wood shop and used it in an oxen trace for log pulling. The links stretched out so far that they froze into position but the welds didn't break - I just got lucky that day. On the other hand, blade billets can go on for a while with lots of welding used before done...it just "depends". Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted August 13, 2012 Share Posted August 13, 2012 Actually re-welding and reworking the welds is supposed to improve them so billets with multiple fold/weld cycles should be better than plain welds---also why people suggest double welding the last cycle. Quote Link to comment Share on other sites More sharing options...
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