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welding 1/2" plate


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Hey all, i am looking for suggestions here. I bought some 1/2" plate that i need to weld together to get the size i need, buying a whole sheet was cost prohibitive. I have mig, stick and tig capability, but not for 1/2" plate. My synchrowave 200 can put out the juice with stick leads. I wanted to maybe use my millermatic 180 (good for 5/16, and just run multiple beads. I don't like stick welding much. I got some less than helpful, condescending responses from a welding forum! I know my machines aren't rated for this thickness, just wondering what you have done. I plan on beveling, preheating and welding both sides with multiple passes. It will be used for an anvil stand for a 460 pound foontanini i am buying.
Thanks
Brian

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well i ain't no expert but....here's a nickel's worth of free advise...bevel both sides,lay in stringers at short lenghs on both sides to help prevent warping, then sew it up in segments. also brush/grind well between each pass. also if using 7018 push the weld instead of dragging it..it will make a flatter weld. hope this helps. jimmy

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For what you are building I would not recommend going with a complete penetration weld, you are supporting an anvil not a bridge. If you want complete penetration the best fit up would be a 45 degree bevel on one side, the other side is square, leave a 1/4 inch gap, put a back up bar on the backside, 1 inch x 3/8 bar stock. Tack the back up bar to the two pieces that you want to join on the back side, leaving the 1/4 inch gap. Now flip it over and weld stringer beads making sure each pass is tied in with the previous weld, the first pass is the root and it needs to tie into the backing bar and both sides of your plate, next will be the "hot pass" you will probably have to weave slightly to tie into both sides of the joint. Now just run stringer beads to fill and cover. It will be necessary to use a strong back to control distortion.
post-10376-0-15613900-1299424972_thumb.j
Your machine is fine for this, either one will do the job. You could clamp a couple of pieces of heavy channel in place of the strong back in my drawing, go slow let it cool down between passes or you will end up with a butterfly

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Ironstein,
I have done a lot of structural steel and clinton has a good method. I think it would be easier for you to to bevel both sides 35-40 degrees. Books will say go 45 but a little less is easier to fill and the inspectors here are ok with it. If you can get some 7024 rod that runs like a dream for making flat welds. At least 1/8 rod maybe 5/32 if you can run it. After learning the rod run one root pass on one side, flip over your plate grind the back to clean metal and weld that side, from there on out you should not have to any more grinding as the slag will likely fall of by itself and keep alternating sides with each pass. Also you should run your beads in the opposite direction you are welding if that makes sense. If you are welding a 10" weld start in the middle and you should be able to get to one edge, say you will run that bead from left to right. Then go to the right edge and go left to right again to meet up with the first weld. That is to keep the plates root gap from opening up like a long straight weld will do.
I think this is easier to do and you do not have to wait several hours between passes, no backing bar to remove and the weld stresses will balance each other out so the plate should stay pretty flat.
Maybe you should think about a better welding machine if you are going to do more of this work?
Rob

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Thanks Clinton. I have been looking for one inch plate for this, but i refuse to spend a ton of money for a large plate. Who knows, i may find what i need before the anvil gets here. I don't know if my welding is up to the task, but from what i have been told from numerous people, it will be very difficult to keep the plates flat. I am up for the challenge, i will probably have a 20 by 20 piece of scrap when i am done!

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Thanks Rob, i am not doing this type of work for money, it is just for a stand for my new anvil. My welding equipment is for small stuff, and eventually i will buy a better mig machine. I may wind up purchasing some one inch plate for this, but since everyone is stating hw challenging this will be, i want to try to make it work! Thank you everyone for your great suggestions.

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So you are going to make a 20" square out of 10" pcs? Maybe weld two 10" pcs together my way and the other two Clintons way and post the results. Then whichever way works better for you put the 10"x20" pcs together that way. Also if you do it this way you are only having to straighten one weld at a time. instead of the cross weld which would be harder.
Rob

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Ironstein,
Here is something similar that I made to support this little crane for getting heavy items on this worktable. About 17"x19" and 3/4 plate. It is pretty flat. Welded both sides. The joint needed an infill piece because when the the plates were touching at the two ends a 3" gap was in the middle. A pipe is welded on the bottom so it does not tip over.
Rob

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Ironstein,
All of this is good advise. Make sure you clamp it to some thing solid across the weld if you don't there is a good chance of ending up with a V instead of a flat plate. Also making a couple passes and letting cool helps.
You should be fine just take your time.

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Thanks Travis. Fosterob, that is a nice platen you have there. I have decided to do some searching and see if any of my structural ironworker friends can scrounge up a plate for me. If i can't find what i need, i will weld the half inch plates together and see if i can keep em flat. In the meantime i made my first tool for my new anvil, it has one and one quarter hardy hole, so i made a hot cut from 4140. Thanks to everyone for your help, i will update this thread with what i decide. post-9924-0-87620400-1299447948_thumb.jp

post-9924-0-01981800-1299447996_thumb.jp

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Thanks Travis. Fosterob, that is a nice platen you have there. I have decided to do some searching and see if any of my structural ironworker friends can scrounge up a plate for me. If i can't find what i need, i will weld the half inch plates together and see if i can keep em flat.

Your structural buddies may be able to get you the end cut of a wide flange beam easier than plate, they have little or no use for them. If you get one 14" wide then you are likely looking at 3/4+ thickness.(W14x99 is 3/4" flanges and something like 5/8" web) The one plate is best. I do not think you should worry about welding the plates you have, it is easy to keep flat. Just know that even if you clamp the snot out of it the weld is still pulling at 70,000 psi so it will just spring when you unclamp it. Unless you stress relieve before unclamping. If you are up this way I can help you if you like.
Rob
Ps That table is 20' long, glad you like it. The pic only shows half of it.
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Thanks Rob. I really appreciate the offer. I may stop by someday. I am always impressed at the help that is offered by the good people on this site. People like you are truly generous and selfless in their offers of help and information. I am going to see what i can scrounge up for a good base, if i can't find what i need, i am confident that with the help offered i can accomplish what i need.

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1/8" 7018 is a good all around rod. It will produce the same weld as 7024, just a little slower. 7024 is a specialty rod in that it will only weld flat and need a high amp input. If you do decide to use 7024, limit your rod diameter to 1/8" to prolong the life of your 200 amp synchrowave.

I would buy a 50 pound box of 7018 and use this as an opertunity to advance your stick welding skills. Stick is still the most versatile process, and often the most practicle or economical solution to welding challenges. 1/8" 7018 will run well on between 110 and 125 amps dc. 7018 is an all position rod, welds great overhead, loves to go vertical up and can weld flat and horizontal as well. As part of the fast fill group of rods, production time is fairly good. Above all, keep the rods dry.

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1/8" 7018 is a good all around rod. It will produce the same weld as 7024, just a little slower. 7024 is a specialty rod in that it will only weld flat and need a high amp input. If you do decide to use 7024, limit your rod diameter to 1/8" to prolong the life of your 200 amp synchrowave.

I would buy a 50 pound box of 7018 and use this as an opertunity to advance your stick welding skills. Stick is still the most versatile process, and often the most practicle or economical solution to welding challenges. 1/8" 7018 will run well on between 110 and 125 amps dc. 7018 is an all position rod, welds great overhead, loves to go vertical up and can weld flat and horizontal as well. As part of the fast fill group of rods, production time is fairly good. Above all, keep the rods dry.




Can you provide a drawing of how you plan on putting the pieces of 1/2'' plate together?


Chuck
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I originally planned on laying them flat on my welding table and beveling the seams to be welded. Today i scored a nice piece of 1 inch plate in the size i need for free from gold coast erectors. A structural ironworker at my job gave me the guys number, he originally planned on charging me, but wound up giving it to me for free! I was so taken back by his generosity that i gave him a damascus knife i made! He was stoked and i think i made a friend! A good friend to have.
Oh and i had planned on jump welding the plates. Now i won't need to cobble anything together, i have to find a new use for those 1/2 inch plates.
Or was that question meant for arftist?

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I would use 7018 too, it runs like a dream once you get the proper weave down. The slag literally peels off by itself on larger welds. The flux on 7018 is non conductive so you can keep the arc short, and bump the rod right against the edges to get it dug in. 6010, or 6011 will create more splatter, but they really dig in on not so clean material. We called 6011 farmer rod because it will eat through rust, dirt, paint, etc..

One method to help keep the plate flat is to peen the weld as it cools. The reason the plate warps is that the as the weld cools it is also contracting. Peening spreads the weld out sideways. For cast iron repairs I use a large straight needle scaler. An air chisel with a rounded chisel would also work. A ball peen hammer will also work, if that is all you have.

I would also agree that welding from both sides would probably be the best method to control warping, but I wouldn't necessarily go for a 100% weld. Vee it just enough to lay one good bead down, and that will be plenty to support an anvil. Especially since the anvil will be bridging the bead, and there will be legs under the plate support it, if I get the gist of how it is to be built. 1/2" plate with a good bead down the middle on both side will support a pickup truck parked on it, and a truck weighs far more than your anvil does. Look at what factory car ramps are made of, stamped sheetmetal. One good bead will be far less likely to warp the plate than multiple beads will. Tack the plates ate each end, and in the middle, then weld 2"-3" flip over, weld 2"-3", and continue stitching the plate. By flipping between beads the welds will counteract each other.

Matter of fact a decent sized bare wire, or better yet a core wire in your MIG with a decent weld prep would give you working results. Drag the gun to get deeper penetration.

Like mentioned before it is just an anvil stand, not a bridge.

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I use my MillerMatic 180 for most of my welds because most of my welds involve welding small stuff. But like you I also have a 200AMP Tig welder. Mine is a Hobart with high frequency arc stabilization which makes it really nice power source for stick welding. Like you I prefer MIG, but there are just some projects that really are better accomplished with stick welding. You have a good power source, why not use it ?

If you have a good auto-darkening hood and have some way to dry your rods it should go a smooth as silk. Alternatively weld concealed welds with stick and finish it off with MIG.

BTW a rod drier can be made using a large coffee can with a light socket mounted through the can side. Use a 40W appliance light bulb. Plug it in, place the rods in the lighted can and cover with a larger can or bucket. It's not very professional but it works. I dry mine this way because my rods can lie around for years between uses. In any case it is good welding practice.

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