Metal "bending"

admin

Using a mig welder to weld a handrail together, having problems keeping the top and bottom rail from bending. When welding the vertical pickets, the horizontal top and bottom rails are bending. The welding is drawing the rails causing them to bend. Any suggestions on keeping this from happening and straightening the rail after it is bent?
Reply:Give it time to cool in between welds and skip around to spread the heat around.  You can also try using heat sink gels to absorb more of the heat.  Kimball Midwest makes a great product for that.Have we all gone mad?
Reply:Are you using tubing or solid bar?The answer depends on what kind of material you are using.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:Brace the top and bottom rails with another piece on metal or tack them in position on a table.  Get all picket in and tacked before solid welding.  Easier to builds rail on a table rather than vertical.
Reply:What tapwelder said.
Reply:Are you welding verticals at 4 inches or 10 feet? Someone here made a large clamp that 'back bent' the top and bottom rails before welding. Doing this on 4 inch centers wouldn't be practical.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:Something similar to what Craig said. Prebend the rail the opposite direction that it's going to bend, experience will tell you how much. I've used that method before and it does make a difference....Mike
Reply:Pre stressing is a good idea, but not always reliable on imported metals because of their poor standards of manufacture.I make jigs that firmly hold the metal first.  But watch your heat levels.  Most decorative things need a good tacking and not much more.  Fit all you pickets first.As you weld.  start on the out side then weld the middle  then go to what the middle bars would be between your outside bars and your middle bars then proceed to find the next "middles" until you have everything tacked firmly together.Make your tacks on the outside seam first if you are welding flat on a table so that your pickets won't pull.  Then tack the insides and finally flip it over to tack the backside.   Let every thing cool and make sure its straight.  Then weld it following the same pattern that you used to tack.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:I would really need to see pics. Before welding, as tacked, and all welded, showing the curve your trying to avoid. I will take a picture of my bender/straightener I built, and post it here within a couple of days. One of the most difficult to avoid "bending" seems to occur whenf field welding sections together. I try my best, and if I get something not straight, I bend it back into place. I have been looking at and wanting an excuse to buy a "Porta-Bender", it looks like a great tool, check it out, I copied the principal of it with a small Port-power piston and a standard pump.Just my  opinion, not from a book, just from the road.Howes Welding Inc.www.howesweldinginc.com
Reply:Thanks for all the info. The material is tubing and the pickets are at 4in centers. Haven't been clamping the top and bottom rails along their entire length. Sounds like I need to make sure it is clamped properly tack...let cool...weld...let cool...then unclamp.
Reply:It may not be practical for the thickness of steel you are using but you couyld try normalizing it "immediately after welding small welds with a cross pein or welding hammer?Tack it keep your welds small, move around and try keep your heat down.
Reply:Originally Posted by Paul CUsing a mig welder to weld a handrail together, having problems keeping the top and bottom rail from bending. When welding the vertical pickets, the horizontal top and bottom rails are bending. The welding is drawing the rails causing them to bend. Any suggestions on keeping this from happening and straightening the rail after it is bent?
Reply:Great explanation Donald.... PS, your from Guerneville?  I am in Sebastopol.The Welder Shop has great deals and reviews on Hobart, Miller and Lincoln Welders.
Reply:WOW !! Nice to meet a neighbor on the web.If you have any other welding questions feel free to email me.BTW I am always telling people to put their address, State, City and phone numberon their web page because you could have someone in your neighbor hood that may have simular interests in what you do, or products you sell.Sincerely, DonAWS certified welding inspectorAWS certified welder
Reply:Originally Posted by tapwelderBrace the top and bottom rails with another piece on metal or tack them in position on a table.  Get all picket in and tacked before solid welding.  Easier to builds rail on a table rather than vertical.