01tundra Posted July 23, 2014 Author Share Posted July 23, 2014 I went ahead and picked up the 3" x 3/4" flat bar, so I'm stuck with it now. I got it crazy cheap, like half of what everyone else locally was asking, so I jumped on it and it's now sitting in my shop. I'm going to attempt to make the 3-leg table design I posted last with the tie bar. I'm planning on fullering the tie bar about an inch overall where it sits between the two back legs, then strap above and below some how (haven't figured the strapping out yet). Maybe instead of strapping I could wrap with small round stock? The shorter front leg will be shouldered and will go up through the tie bar. Not sure yet how to actually fasten the front leg to the tie bar, if I do a tenon I think I would have to upset it on the top side to get everyhthing to hold together. The other option could be to roll the front leg at the top and use a couple large rivets, not sure which would look the best. Bending the 3" bar across the width to get the two rear legs to flare at the bottom still worries me a little. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 23, 2014 Share Posted July 23, 2014 You could heat shrink the tenon in place if you didn't want to countersink around the top, rivet the top of the tenon and then file it smooth and even with the bar. I heat shrunk the head of a warhammer about 20-25 years ago leave a stub to rivet it tight again when it loosened---hasn't happened yet and has seen a lot more hammering on stumps, junked refrigerators, cars, etc than the table will ever see! I made a drift from the piece that was the tenon I had the proper size to fit closely and shrink *tight* as the mortised piece cooled... Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 23, 2014 Author Share Posted July 23, 2014 I think riveting the top of the tenon and leaving a raised rivet head would look pretty good. I'd have to probably use my torch as the heat source on that step though. Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 23, 2014 Author Share Posted July 23, 2014 The largest drift I have is 1" round. So do I just forge the end of the 3" x 3/4" front leg down to something slightly less than 1" round, slip through the 1" drifted hole in the tie bar and then use my torch to heat and upset the end of the tenon into a rivet head? Think 1" will be large enough? Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 23, 2014 Share Posted July 23, 2014 Well if you are using A-36 then the yield strength of the steel will be on the order of 36000 PSI. Thus yield strength of 1" round is on the order of 28000 pounds. Even with leverage effects it's still a bit overkill don't you think? Now I wouldn't go round, go square so nothing can twist around under lower forces. Using a 3/4" sq tenon would get you down around 20,000 pounds for the yield force needed.---dare you risk it? Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 23, 2014 Author Share Posted July 23, 2014 Drift round and then file square on the tie bar? Try to forge down the flat bar to 3/4" square or cheat and cut it down with a saw? Quote Link to comment Share on other sites More sharing options...
WayneCoeArtistBlacksmith Posted July 23, 2014 Share Posted July 23, 2014 You are calling it a Sofa Table but it is 36" tall so I assume that it goes behind and next to the sofa as opposed to a "Coffee Table" which would be free standing and low in front of the table. Considering your original design, and if it goes behind the sofa, could it be attached to the sofa, therefore eliminating the stability problem? Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 24, 2014 Author Share Posted July 24, 2014 I made a typo in my original post Wayne. The top will actually be 30" high and the table will free-stand behind our sofa that's 31" tall. Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 24, 2014 Share Posted July 24, 2014 I make a lot of tables. Forge welding large stock is a nightmare. I suggest using tenons where necessary. Slit and drift where you must, then CHEAT and tig weld where the tenon comes thru and peen the tenon to hide the tig weld. Rock solid and looks great. Think reality. John Quote Link to comment Share on other sites More sharing options...
gearhartironwerks Posted July 24, 2014 Share Posted July 24, 2014 be careful on the long sloping curves as they tend to flex, and that's not a good thing for tables. john Quote Link to comment Share on other sites More sharing options...
anvil Posted July 24, 2014 Share Posted July 24, 2014 How about a top view? 3x3/4" with 1" tenon, see the problem? Quote Link to comment Share on other sites More sharing options...
anvil Posted July 24, 2014 Share Posted July 24, 2014 Round or square tenon doesn't matter. The other end is attached to the table top Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 24, 2014 Author Share Posted July 24, 2014 How about a top view? 3x3/4" with 1" tenon, see the problem? The 1" tenon would be going through the 3" wide plane, I may be missing something though? I'm going to go with a 3/4" tenon since my stock is already 3/4" thick. I think I will rough cut the tenon out and then forge to clean up the shape. When using a square tenon and upsetting to create a rivet head, do you leave the top profile of it square or file it round? I'm talking from an aesthetics standpoint. Also, does anyone have a recommendation on how much of the 3/4" square tenon should be left above the surface of the tie bar to make a decent sized rivet head? I want it to be visible for a more industrial look. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 24, 2014 Share Posted July 24, 2014 Rivets don't have to be round... I would do it sq or even rectangular---tenons don't have to be sq or round... As for how much to protrude that's sort of up to you and if you have a torch to heat while hammering and the shape of the final boss (you could make a rivet set with the shape you want in it---or just hammer it freehand---may want a thin sheetmetal shield to protect the other piece while you hammer on the rivet.) Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 24, 2014 Author Share Posted July 24, 2014 I thought a little more about my torch comment. Due to how this will be staged, I can simply heat the tenon in the forge and then insert into the tie bar and hammer. I may indeed need a torch for a second heat if I don't get it done on the first. So for the hole in the tie bar, I like the thought of a square tenon, I think it will look better with my base design. If I don't have a square drift large enough, do I drift with a round to approximately 3/4" and then file the sides to sqaure up the hole, or is there a better solution? Quote Link to comment Share on other sites More sharing options...
anvil Posted July 24, 2014 Share Posted July 24, 2014 You got it, your tenon was 1" and the bar 3/4". Tenon head length: 1-1/2 x diameter of tenon shaft for head minimum. Actual length is by design and a test piece will tell you what you need. . Do rivit head profile how you want, its your aesthetics ;) . Make a square drift, lol, you are the blacksmith/ toolmaker. It can be mild steel. Use your parent stock if you don't have anything else. For a drift, especially for a one off use, no heat treatment needed. The head may mushroom with use, but that's easily dressed. As Thomas said for heading your rivit. One of my headers is pyramidal in shape. About 1" at base and 1" tall. I forge the pyramid on the tenon, then use the header for final dress. I forged a pyramid on the end of a 1" bar and sunk it into a die. I also use it to make nuts. Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 24, 2014 Author Share Posted July 24, 2014 Got it, great ideas. I like the pyramid rivet head, I think it will give me the look I'm shooting for. Never thought about making a header like you describe, but it makes sense to me. I may try to form the rivet head by hand and leave it a little unfinished looking on purpose, if it's possible to get the look I want without the use of a header. I'm new at this and still haven't quite opened my mind fully to solutions to problems, but I do feel like I'm on a steep learning curve thanks to all of you guys. As dumb as it sounds, I sometimes need to be reminded that I'm a blacksmith... I truely appreciate everyone's help - thanks again. Quote Link to comment Share on other sites More sharing options...
anvil Posted July 24, 2014 Share Posted July 24, 2014 Brainstorming is a lot of fun, all we need is a coffee shop with a cute waitress and a napkin. We could solve all the worlds problems in one heat. Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 27, 2014 Author Share Posted July 27, 2014 I scored a big cast steel disc from the scrap yard on Friday, it's 32" dia x 1-3/4" wide and 340 lbs. Made some removable support legs for it and used it as a bending anvil, works great. Was also given a smaller cast iron disc that worked for the tighter radius of the leg at the top. Got the first leg about 80% complete yesterday, I've come to the conclusion that I really need a power hammer........ Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 27, 2014 Author Share Posted July 27, 2014 Got Leg #1 pretty close to complete today......only a few more to go. Quote Link to comment Share on other sites More sharing options...
WayneCoeArtistBlacksmith Posted July 27, 2014 Share Posted July 27, 2014 Just keep in mind, "A power hammer just lets you make bigger mistakes quicker." Of course, I have a power hammer and wouldn't be without it. Quote Link to comment Share on other sites More sharing options...
Jim Coke Posted July 28, 2014 Share Posted July 28, 2014 Greetings 01, A power hammer would not help you much with that form. Not even Waynes Super Blue.. If it was in my shop I would roll the legs on my rolling machine. There is another idea that you can do ... Just weld the first leg to a angle iron for a form.. Use bending forks and a clamp.. It will go easy.. Simple to do. Nice find at the junk yard.. Drill and tap some holes in your large disc for a platen table as mentioned earlier. I have had several and they served me well.. Oh and go back to the yard and secure the others you won't be sorry... Good luck Forge on and make beautiful things Jim Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 28, 2014 Author Share Posted July 28, 2014 I was thinking about using the first leg as a form. So instead of bending the second leg on the inside or outside of the form leg, would it make more sense to weld guide rods to a plate that extended above the upper edge of the form leg on each side in intervals so the second will be the exact same size? Or is it easier to bend around the outside and then close the arc a little or around the inside and open it up a little? If any of that mess made sense at all...... Quote Link to comment Share on other sites More sharing options...
Jim Coke Posted July 28, 2014 Share Posted July 28, 2014 Greetings 01, Just form it on the outside and than close the arc a tad. It will work just fine. Forge on and make beautiful things Jim Quote Link to comment Share on other sites More sharing options...
01tundra Posted July 28, 2014 Author Share Posted July 28, 2014 When I draw it up in CAD following the outside of the first leg it puts the second one pretty far off due to material thickness. What about cutting up some of the 3/4" round rod that was given to me and weld to the sides of the first leg to act as guide pins? This way the second leg could be formed on top of the first (on edge)? The biggest problem I have is that the size of the stock and my coal forge only allows me to heat short sections at a time. It may be easier to just use my bending anvil again and then match it up as close as possible to the first leg. Quote Link to comment Share on other sites More sharing options...
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