Butt welding 1" steel?

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I was volunteered to experiment butt welding two pieces of 1" steel together to extend the length of a mold. The length of the joint will be about 36" long.I am a welder by trade but in my department, we only do stainless tig and the thickest I have ever welded was about 1/4".The weld will have to be ground smooth on one side only once finished.My question is what would the best process be? I was thinking stick but have zero experience welding on steel this thick. Any help or advise would be greatly appreciated
Reply:i'd bevel the side you don't have to grind . do full penetration from that side .i guess it would be the outside of mold . don't have pic of it but i'm sure you know what i'm talkin about.  bevel both pices to the outside  7018 1/8 "rod . run stringers all the way out
Reply:I would bevel both plates so that you have a "v" groove joint and I would use a removable backing bar on the un-beveled side of the weld.  Either use MIG or Flux Core g/s to weld the joint.  Since it is 36" long, you will have a ton of restarts if you use stick to weld it.
Reply:A double V won't warp if you alternate sides.  It will take less filler too.Tig will do it, but take a lot of time.  Spray Mig would work,PULSED SPRAY is the way to go 3/16" 7018 @ 240 amps would be nice  So would 7024.Dual shield would be the fastest.  What kind of steel is it?  David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:I agree with David. beveling both sides of both peices and alternating passes on each side will help control distortion. Preheating is entirely appropriate. I would not even consider tig though, personally. Stick over tig, but wire over stick!City of L.A. Structural; Manual & Semi-Automatic;"Surely there is a mine for silver, and a place where gold is refined. Iron is taken from the earth, and copper is smelted from ore."Job 28:1,2Lincoln, Miller, Victor & ISV BibleDanny
Reply:Originally Posted by David RA double V won't warp if you alternate sides.  It will take less filler too.Tig will do it, but take a lot of time.  Spray Mig would work,PULSED SPRAY is the way to go 3/16" 7018 @ 240 amps would be nice  So would 7024.Dual shield would be the fastest.  What kind of steel is it?  David
Reply:Another vote for the double v groove.Yup
Reply:double bevel ( like a vee but only one plate gets the bevels.less weld metalplan on preheating and post heatingwhat is the specific materialinsert thoughtful quote from someone else2000 Thermal Arc 300GTSW 3.5 hours1946 Monarch 20 x 54 Lathe1998 Supermax 10x54 Mill2004 Haco Atlantic 1/2" Capacity Lasernot mine but i get to play with it
Reply:Well basically my questions same as david what type of steel? What sort of stresses will this welded item be subjected too?Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Originally Posted by eyeball engineerwhats the scoop on pulse spray?  is pulse spray the same as spray just with a pulsing frequency?
Reply:Originally Posted by David RLess heat input and I have more control.It goes on like butter David
Reply:If you're welding on a mold, I reccommend finding out what grade of steel it's made from.Is it a stamping mold, or a die cast mold?  Or something else entirely?If it's made out of a tool steel, you'll need to match the weld filler metal to the mold steel.As far as process is concerned....1 - What welding power supply(s) do you have available?  Or would your company consider renting/buying equipment just for this project?2 - Can you weld this joint in the flat position?  Or will some or all of the weld joint be vertical and/or overhead?  Can you reposition the mold to keep the weld groove in the flat position all the time?3 - How practical is it to machine the weld surface on the inside of the mold?4 - Can you weld temporary bracing on the back side of the weld to hold the pieces in position and prevent the weld from pulling?  Or is it possible to clamp the parts in a jig to hold them in place?All of these would dictate the process and procedure used for this weld.In a perfect world, I'd recommend a single V-Groove weld with a backing strip.  a 60 degree included angle, and a 1/8" - 1/4" root opening with 0 land or root face.Weld the joint in the flat position, using spray MIG with a suitable filler metal alloy.  Could be gas shielded FCAW, or solid wire.If you can clamp or restrain the joint, use a single V-groove with a backing strip.  If not, then the double bevel recommended early makes more sense.If you're using a flux core filler product, plan on back gouging the root or grinding the root face.  This would be especially important for the double bevel joint prep.Gouging and back welding the root face would also give you another means of pulling the weldment back into alignment if it's impractical to restrain the weld joint.Sorry for throwing so many variables out on the table.  With a picture of the weld and some more details about the mold alloy, I could be more specific.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:IMHO-  Double V, passes on alternate sides, and stick.  Stick gives better known penetration than wire if you're not familiar with the settings required to give adequate heat when welding with wire.  Most beautiful wire weld in the world can be crap if the heat wasn't rightRead an article somewhere about structural steel something or other in Japan.  They did a study and found that stick welded stuff held up better in earthquakes than wire welded stuff.  All hearsay until I can locate the article, or IF I can locate the article.Last edited by farmersamm; 01-23-2009 at 05:54 PM.Reason: spelling, and added BS     LOL"Any day above ground is a good day"http://www.farmersamm.com/
Reply:i agree with double v but if you want smooth surface on one side without grinding . bevel both plates same side  as for start stops i'd still use stick as 36" of weld you'd want to move around and move the heat so as not to warp. at least 2 or 3 passes and then i'd go with mig . maybe pic of project and like everyone alse what is the material 2 be welded
Reply:Double bevel with .072 or 5/64 NR232(or NR311Ni or NR305 if you are welding this in the flat position only).'Mike
Reply:MIG Spray is very hot and gives very good penetration.  I suspect you're thinking of Short Circuit MIG, which is notorious for poor penetration if the welder technique is bad. Originally Posted by farmersammIMHO-  Double V, passes on alternate sides, and stick.  Stick gives better known penetration than wire if you're not familiar with the settings required to give adequate heat when welding with wire.  Most beautiful wire weld in the world can be crap if the heat wasn't rightRead an article somewhere about structural steel something or other in Japan.  They did a study and found that stick welded stuff held up better in earthquakes than wire welded stuff.  All hearsay until I can locate the article, or IF I can locate the article.
Reply:Bevel each side of the plates to 22º. The backing strip would be 1/4 -3/8 inch thick. 1.5 inches wide.If you use a backing strip you will need a special scarfing tip for the torch to remove the strip and it does require skill to keep from gouging the surface.Just use a TIG for the root pass. The stick or wire feed for the remainder. You must CLEAN very well between each pass. It may take 14 passes to complete. You can look it up to see the order of the welds.IF it is a structural weld check the book.Last edited by Donald Branscom; 01-25-2009 at 02:38 AM.AWS certified welding inspectorAWS certified welder
Reply:joint design aside i would use whatever process your are comfortable putting in a sound weld with. if that means you need to spend 2 days with a tig welder then so be it. personally i would put a tig root pass in then use FCAW to fill and cap with plenty of pre-heat specific temp dependent on exact material.
Reply:I would agree with QUASI on this.I passed my qualifications on 1 inch plate with FCAW  in overhead.AWS certified welding inspectorAWS certified welder
Reply:Originally Posted by A_DAB_will_doMIG Spray is very hot and gives very good penetration.  I suspect you're thinking of Short Circuit MIG, which is notorious for poor penetration if the welder technique is bad.
Reply:I guess what I'm saying is, that there's more skill to making a good wire weld than the beginner might think."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Wow! Thanks for all of the responses guys. The grade of steel I'm not sure of. It's not structural and it CAN be welded in the flat position. We have mig and tig welders. The molds go into an oven and are kept at 350 degrees 24/ 7. The finished side will be machined then sanded and polished smooth to about a 10-15 ra finish. We don't have a pulse spray and highly doubt the company is gonna purchase one for this job. But I think if it becomes too much of a hassle, they'll just bite the bullet and buy a new mold. Might end up costing them less in the long run.Once again, I appreciate all of the feedback and I'll be sure to keep you posted. BTW, I know it is def. not tool steel. I am almost positive it as some grade of hot rolled stuff and not cast.
Reply:You have to know what kind of steel it is before you can weld it properly.You also have to know what the service and environmental conditions are.  Temperature, pressure vessel, impact/shock, etc.Also you (or we ) need to know if you can weld from both sides and what the position of the weld is or can be.  It sounds like you can get to both sides (as the mold will be finish machined afterwards) and you say you can do it in the flat position (that means you can do it with GMAW spray, no spray pulse needed).TIG will take a while.Stick may be OK, but will take a while and have LOTS of starts and stops.MIG (especially spray or pulsed spray) would go the fastest.Hmmm, 1 inch thick plate and 36 inches long would be about 5 pounds of weld filler.  A good GMAW or FCAW wire could easily put down that much filler in about an hour.  You'd probably have to actually slow down and take some breaks to not get the plate too hot!Also, you have to be able to control the welding distortion and know how much distortion is acceptable in the final object.For flat plate distortion control on 'thicker' plate, usually 60 degree double V-bevel (with a land in the middle) and alternating sides -minimizes- the distortion.You would probably be looking at 300+ amps in spray mode GMAW with 'thicker' wire.  You're not going to do -that- plate with some 0.025!  The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by farmersammI guess what I'm saying is, that there's more skill to making a good wire weld than the beginner might think.