Help with welding round-on-flat

admin

I need to weld part of a piece of 3 1/2" pipe onto a flat piece.  Both are about 3/8" thick. The problem is that I can't seem to get the weld deep into the space between the pipe and the flat piece.  The bead keeps jumping onto the metal before I can get it "down in there."  I attached a little graphic below to demonstrate this.This is with a Hobart 235 AC welder.  My everyday go-to rod is 7018AC, but sometimes I use 6011 for dirty stuff - I live on a small farm.  I really need to get this welded securely.  Can anybody give me a tip?  Thanks a bunch. Attached Images-RuarkLincoln 3200HDHobart Stickmate LX235TWECO Fabricator 211i
Reply:RuarkThis is a text-book 'joint to avoid'.The common remedy is to add a run of flat-bar perpendicular to your flat piece  -  in contact with a tangent of the pipe.  This provides two easy access joints, and the FB is disposable if it ever has to be cut apart.Opus
Reply:I'm no stick pro but are you able to rotate the joint 45 degrees so you are welding in the flat position?  Maybe that would help the metal flow down into the root.Lincoln Vantage 400Trailblazer® 302 Air Pak™Miller Dynasty® 350Millermatic® 252Millermatic 350P AluminumSyncrowave 351LN-25 Pro (Two)Multimatic 200 (Two)Diversion™ 180Spectrum® 625 X-TREME™Thermal Dynamics ‑ Cutmaster 52
Reply:As mentioned it's a poor joint configuration. Best option I can think of if it has to be done this way, would be to run the smallest rod you can as your root to get in as deep as possible, then run another pass on top. I'd probably opt for a 6010/11 root to limit porosity on the back face of the weld, then cap with 7018 if you are  running stick."Welded securely" can mean a lot of different things depending on the job at hand. Something that's safety critical would have a different level than say something on a plow where if it breaks, it's more an inconvenience than anything else..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:http://weldingweb.com/vbb/showthread.php...idge+generator4th post down.
Reply:Should be able to run a 1/8 6010 hot and get it deep in there. After a pass or two with that you can switch to 7018 and fill it in.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Ruark  I've had the same problem before.  I found I really needed to jam the rod in there to get it done (otherwise you're long arcing).  Then build the weld bead out on each pass.  Not a great way to do it so I avoid this type of joint design now.The suggestion to use another piece of flat and weld to it is exactly what I did the next time I came across it. Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Smythe solution is weld a couple of pieces of angle iron to it first, then you are just doing standard fillet a welds when I put pipe on flat steel Attached ImagesTiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Feed Lot gate "hinges" were 1/2" ID.I welded those, by using a smaller rod diameter with multiple passes.I just repaired a Back-Blade with a 3.5" center pipe by using two 3/8 thick plates as described by the other poster.It all comes down to strength/stress on the welded joint.
Reply:3" pipe is 3.5" OD.  3.5" pipe is 4" OD.  Either way, some 1-inch wide flat stock should work to bolster.  Shown with 1 x 1/4 flat stock.  Can go thicker or thinner without affecting the spacing of the flat stock. Attached Images
Reply:I really appreciate the replies, thanks a million.For what it's worth, the stress on the round pipe will be lateral... that is, tending to "roll" it across the round piece.  No lifting or twisting stress.  I'm going to ponder this for a while...-RuarkLincoln 3200HDHobart Stickmate LX235TWECO Fabricator 211i
Reply:If the loading on the pipe is tending to roll it along the plate, bolstering either with flat stock, angle, or channel is advantageous because it puts your weld joints out at a greater moment arm, reducing the joint stresses.  Flat stock would be cheapest if you have a lot of it to do.
Reply:Originally Posted by dbotosIf the loading on the pipe is tending to roll it along the plate, bolstering either with flat stock, angle, or channel is advantageous because it puts your weld joints out at a greater moment arm, reducing the joint stresses.  Flat stock would be cheapest if you have a lot of it to do.
Reply:If it's a lateral load, there'll be shear reactions too.  Do they do free-body diagrams in high school physics?  Been a while since high school...Rebar also makes for quick-and-dirty bolsters.  Probably not quite as nice as the flat stock, but just another option.Last edited by dbotos; 01-18-2013 at 12:11 AM.
Reply:Originally Posted by dbotosIf it's a lateral load, there'll be shear reactions too.  Do they do free-body diagrams in high school physics?  Been a while since high school...Rebar also makes for quick-and-dirty bolsters.  Probably not quite as nice as the flat stock, but just another option.
Reply:220 amps 3/16 rod ,weld both sides.
Reply:Originally Posted by dbotosIf it's a lateral load, there'll be shear reactions too.  Do they do free-body diagrams in high school physics?  Been a while since high school...
Reply:Originally Posted by ironrail220 amps 3/16 rod ,weld both sides.
Reply:#1- use 3/32 rods on the higher amp range#2- grind a flat spot on the round piece#3- if you can, redesign- avoid that type of jointi.u.o.e. # 15queens, ny and sunny fla
Reply:Originally Posted by SuperArcRebar is just some fun stuff to make all kinds of €rap.  I love the #7 and 8 sizes.
Reply:Yes, really. you will never get a weld all the way into the root.So make big honking welds farther out.Last edited by ironrail; 01-19-2013 at 11:38 AM.
Reply:Originally Posted by docwelderin my experience re-bar is funny stuff to weld. be very careful if you utilize it to make anything used for lifting or supporting a load especially in tension. the life you save may be your own!
Reply:Some interesting info on rebar:http://www.sizes.com/materls/rebar.htm
Reply:Originally Posted by SuperArcI use it to make rifle target stands, supporting railroad track tie-down plates.  Anything critical for load bearing applications and you're right, I wouldn't use rebar for that.
Reply:Flat stock would work, but even though it's more expensive and weighs more, the proper fit/size angle iron would be easier to fit up and work with, plus the base would give you two weldment stringers on the corner and inside edge (before adding the pipe).