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Hey guys, I'm new to welding and new the forum. I learned to gas weld through an evening class offered at my wife's college and have been enjoying it quite a bit. Something about the brass and the steel joints just does it for me. I've made some tables and other items and want to weld a pull up bar for my garage gym. I've already purchased the steel and am ready to get started. The design I'm going to be duplicating is the one below made by "Rogue Fitness". I really want to braze this thing together but the steel yard guys recommended that I MIG it. I 'can' MIG but am much more comfortable gas welding. Do you think I'll be okay with brazing it? The last thing I want to have happen is it to break on me mid pullup.Thanks!Last edited by Grizzlybagworks; 04-11-2014 at 01:56 PM.
Reply:Through the years many airplane-, car-, bicycle- and motorcycle frames have been brazed and they work just fine. With a good design and good brazing you will be just fine. With a bad design you're f*cked no matter how you join it together.
Reply:First, brazing is attaching two pieces of metal using brass, please stop being redundant.Second, brazing is NOT nearly as strong as a good weld.Just ask yourself, would I feel safe putting my 200 lbs on this thing? It must be sturdy and properly attached to a strong wall.One can do beautiful things with brass and other decorative metals. But when it comes to inexpensive strength, nothing beats steel!Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:First, brazing is attaching two pieces of metal using brass, please stop being redundant.
Reply:Wow! Thank you for the quick responses! Originally Posted by G-sonThrough the years many airplane-, car-, bicycle- and motorcycle frames have been brazed and they work just fine. With a good design and good brazing you will be just fine. With a bad design you're f*cked no matter how you join it together.
Reply:The design of the joints in that picture (if you build it like that) is optimized for welding, and not brazing.Brazed joints are nearly as strong as welds in shear, but not so much in tension. I'd expect the upper right corner to fail under repeated stress. It will tear apart at the top, and once the crack starts, it will open up like a zipper.Now if you were to redesign that piece taking into consideration the strengths of brazing in different joint configurations, I'm sure you could get it to work.
Reply:If you are taking an oxy/fuel torch and heating the steel workpieces and connecting them with molten brass/bronze filler, then you are brazing.If you are taking an oxy/fuel torch and heating the steel workpieces and connecting them by melting the original steel and adding some steel weld filler, then you are welding. Oxy-fuel welding in this case.If you take a source of electrical energy and use that to make an electric arc and use the heat from that electric arc to melt the steel workpiece(s) and also add some steel weld filler to the joint and let the molten original workpiece steel and the molten steel filler material achieve a state of Zen oneness, then you are arc welding. (you can arc weld many different materials, some more easily than others, but the distinction is that the parent material and the compatible weld filler are both melted together to make the joint.)Arc welding can be SMAW or GMAW or FCAW or GTAW or SAW.Welding is when the parent material and the filler (if applicable) both melt into one-ness to make the joint.If you didn't melt the parent material but did melt the filler, then you are either soldering (think copper plumbing pipe and solder, or electrical wires and solder, etc) or brazing.If you learned oxy-fuel welding in your adult-ed class, and you are comfortable and competent in that process, then go ahead and oxy-fuel weld your project together. The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by G-sonThrough the years many airplane-, car-, bicycle- and motorcycle frames have been brazed and they work just fine. With a good design and good brazing you will be just fine. With a bad design you're f*cked no matter how you join it together.
Reply:lol we have brazing alloys good for 70,000psi, braze away my friend !
Reply:Brazed joints are remarkably strong IF well designed. In many cases the joint can exceed the strength of the base material. This article deals with silver brazing, but brass brazing can give similar results.http://www.aws.org/wj/amwelder/9-00/fundamentals.htmlBut joints are a poor way to design a brazed joint. Lap joints make a much stronger connection when brazing. Socket welds would be a close 2nd and filets fall some where in between. If you redesign the frame a bit, say bend the ends of the braces so they lap the wall piece and top piece, and reinforce the top to wall joint with a piece of angle so you have a lap joint to reinforce the but joint, you won't have any trouble at all. Remember we are talking about brass brazing rods having 63,000 psi tensile strength. I drew the basic idea on your pict with green and blue, but there are plenty of other ways to design this so it would work just fine.I wouldn't be at all scared of brazing. In Jr high I helped a friend make a couple sets of tree climbing spikes by brazing. Instructor had me do the brazed joints since I was practicing OA welding and brazing. They were more than enough to support a 250 lb person on a pole when the instructor tested them.Last edited by DSW; 04-11-2014 at 05:33 PM.Reason: Forgot pict.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by mike837goFirst, brazing is attaching two pieces of metal using brass, please stop being redundant.Second, brazing is NOT nearly as strong as a good weld.Just ask yourself, would I feel safe putting my 200 lbs on this thing? It must be sturdy and properly attached to a strong wall.One can do beautiful things with brass and other decorative metals. But when it comes to inexpensive strength, nothing beats steel!
Reply:You aren't gonna fall far !
Reply:Perhaps, but a konk from that bar into your head isn't going to be fun.Anyway, read what DSW says. Think a little about how the pieces will fit together, and with just a little rekerjiggering you can easily make the equivalent with brazed joints.
Reply:Originally Posted by BurpeeA good braze is stronger than a bad weld.Lets get some 3/8x 4" hot roll flat bar and do a "T". You prep yours, any way you want, and use a 100 amp (name that flux core). I'll do a fillet(prepped my way) with 1/8 brazing rod and a #6. Yours will break before mine.Matter of fact, mine wont break at all.It'll fold like an omelette !
Reply:Are the vertical against the wall members made of channel or rectangular tube? Consider mortising the horizontal pieces into the vertical. A brazed mortise and tennon joint would be stronger. Once you've done this test by putting 3 times the potential load you expect on it.
Reply:Originally Posted by Willie BAre the vertical against the wall members made of channel or rectangular tube? Consider mortising the horizontal pieces into the vertical. A brazed mortise and tennon joint would be stronger. Once you've done this test by putting 3 times the potential load you expect on it.
Reply:DSW, Thank you so much for that pic! I just saw it now. I like the idea of bending the tube and doing a lap joint but I don't know how to bend the 11g square tube. Put it in a vise and crank on it? The welding studio that I'm working out of really doesn't have more than a band saw, grinder, belt sander, drill press and vise. Thank you for your input!
Reply:If it's simply tube, make a cut on each corner down the side and bend the top and bottom back to give you your laps, cut the two side pieces off flush with the back of the two bends. You have a torch, so a bit of heat and the pieces will bend super easy and give you a nice tight fit. Cuts can be made with a hacksaw or grinder with slitting wheel.Or do what I suggested earlier and add a piece of angle iron overlapping the tube on one side and the wall plate on the other. If you want extra strength, do top and bottom. Much easier and faster than cutting the tube and bending..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Where are you located?
Reply:Plasma, Jig saw, drill a line of holes well on the waste side of the line, then move up in drill size, clean with a file or die grinder. There are dozens of ways, dependent on the tools at your disposal.
Reply:Im confused with the 52" span. Most framing in the US is 16" on center or 24" OC. I would think 48 or 64 inch span unless your hanging from a concrete wall.
Reply:Originally Posted by Fnord5Where are you located?
Reply:I'm in Sacramento. If I can help lemme know.
Reply:Don't play games.Weld it....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I am also confused with the 52 inch, you are not going to find a stud in most walls at that distance. As insaneride said.Angle brackets with bolts and nuts?
Reply:Originally Posted by mwshawI am also confused with the 52 inch, you are not going to find a stud in most walls at that distance. As insaneride said.
Reply:OOps Grizzly, Iguess its your 52". The ffity two inch is rite ; just make sure the gussetes are at 16" OC and ; weld it up
Reply:Ummm...you can weld with OA too! You don't have to go to MIG, just because you want to weld. You could use the OA torch for that, with the appropriate fille (R45 or R60 would be fine). Didn't they teach you to set the torch for welding too?I would weld it, with OA. (Well, OK, "I" would make it out of aluminum and design the joints for solid rivets, but based on the processes you mentioned, I'd gas weld it). I agree that the joints you see on the original are optimized for welding.KevKevin / Machine_Punk from The Aerodrome Studio - Lincoln PowerMIG 210 MP - Meco N Midget w/custom welding station - Vintage Victor 100Current Projects: The Aerodrome Studio
Reply:I think if you made fillet brazed joints, with a bead built up, as in the photo, you would be good....unless you think you would apply more stress doing a pullup, than a cyclist applies on the bottom bracket during a sprint.Gorgeous, huh?But they don't look that good before they are sanded down.No, it is not my work
Reply:Not going to push much with a wood crank and peddles.
Reply:Originally Posted by geezerbillI think if you made fillet brazed joints, with a bead built up, as in the photo, you would be good....unless you think you would apply more stress doing a pullup, than a cyclist applies on the bottom bracket during a sprint.Gorgeous, huh?But they don't look that good before they are sanded down.No, it is not my work
Reply:That is part of the jig/stand.
Reply:weld it, or braze it. don't matter as if you do either right you ain't going to tear it up by using it for intended purposes. Now if you are going to be hanging a D8 off of the bar then you might want to first check and see if your anchoring screws will hold the weight as they will most likely fail before the brazed or welded joint will.I love the look of a good brazed joint. The design you have looks good for either brazing or welding so knock it out. You can use what ever spacing you want so long as you have anchor backing blocks in the wall. I personally don't like anchoring to a wall. I prefer a free standing unit, but that is just my opinion.
Reply:Mig weld it or Gas weld it if you enjoy the experience . IMHO
Reply:Wouldn't it be a little to expensive to braze this? I mean oxy-fuel ain't cheap!Lincoln pro core 125 14''chop saw7 inch grinder,2-4.5 inch grinders,electric die grinder.Half inch drillAnd alot of hand tools
Reply:Make it out of aluminum and use that alumiweld stuff.
Reply:okay..here you are 75 opinions later..go make one and try to break it..
Reply:After reading about the possibility of brazing this project, and the strength of brazing, I have some Nassau Brutus/G 3/32 brazing rod rated at 100,000 psi and know there are other brazing rods that are even higher rated. Just for your inquiring minds. Bob
Reply:Thanks so much for all the input guys! Helped hugely in deciding how to approach the project. I'm going to mortise the top joint to strengthen that area up and then fillet braze the rest of the joints. I'll post some photos of the project after it's finished. I'll hopefully get it finished this week. Originally Posted by Fnord5I'm in Sacramento. If I can help lemme know.
Reply:Could of had it done by now with a good coat of rust already forming if it weren't painted. Just tie it together with some bailing wire and call it good. maybe a little duct tape for appearance sake.
Reply:You forgot the JB weld. Originally Posted by BistineauCould of had it done by now with a good coat of rust already forming if it weren't painted. Just tie it together with some bailing wire and call it good. maybe a little duct tape for appearance sake.
Reply:When I was at the Kent White's "Mastering the torch" class, he had the torches (running small tips) on pretty much all day...medium bottles last him about 7 days of classes, with the torches running a good 4 hours each day. Of course, these are Meco Midets, but you are intentionally running the flame 'cooler' for the soldering and brazing. Originally Posted by flux core joeWouldn't it be a little to expensive to braze this? I mean oxy-fuel ain't cheap!
Reply:i hope we get to see the finished product.i.u.o.e. # 15queens, ny and sunny fla
Reply:Originally Posted by Warroad140You forgot the JB weld.
Reply:I'd like to point out that the entire front end of this Jag is has brazed joints.
Reply:JB Weld???? What you a amateur????I was thinking duct tape and baling twine.
Reply:Originally Posted by BistineauCould of had it done by now with a good coat of rust already forming if it weren't painted. Just tie it together with some bailing wire and call it good. maybe a little duct tape for appearance sake.
Reply:Alright, I'm going to show my ignorance and ask:I always thought steel was stronger in tension than in compression. Why not put the diagonal brace above, not below, the bar?Hobart cutting/welding torch.MM252, and nothing else. My first welder. Buy once, cry once....but I really would like a nice 50/60A circuit to run it at full strength.A bunch of ideas, and not enough time and money to bring them to life.
Reply:Because many joints are stronger in compression and weak in tension. |
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发表于 2021-8-31 22:31:53