Need advice on butt welding 1" plate steel

[Ocular Engineer]

I am NOT a welder by trade but I do a lot of welding at work. Most of it is on steel that is 1/2" thick or less.

I have been asked to weld two 4' x 4' by 1" plates of steel together to make one 4' x 8' plate. It will be used to smooth out the transition between a barge and a dock. Trucks will be driving over it.

I have already started prepping the steel by grinding a bevel on each side of the joint to be welded. I have 1/8" 7018 on hand, but I could probably get larger if I need to. I'll be using our Miller Syncrowave 200.

Can someone help me w/ procedure and/or technique so I don't screw this up?

Thanks for any help.

[Freddytk421]

Wow thats a lot of welding. The best advice I could give you is get comfortable because you are going to be down there a while. It should not be that hard because its in the flat position and it's so big and thick you should not have to worry much about warping. set the machine to about 120 amps and just lay bead after bead after bead......don't forget to keep your 7018 rods hot in an oven and clean each weld very well with a wire wheel before going back over it. You should be really good by the time you are done with that project. Do you have a specific question like about the root or the filler or anything like that?

[Ocular Engineer]

I guess I am most concerned about the plate warping.
I have the plate prepared and will be starting the welding on Friday. Each corner is beveled at about 45 deg and there is about 1/4 to 5/16" of vertical contact when the plates are matched up. The V is about 3/4" wide and 3/8" deep on each side.

I found that we have a large box of 7024, 1/8". It is good for downhand and I ran some test welds on some 1/2" plate, 180 to 195 amps. It flowed nicely. I can run the weld speed nice and slow w/ a little side to side and it will fill up the V.

So, my plan is to preheat the weld area then weld 3 6" beads on one side (center and each end of the weld). Turn the plate over and weld the other side, starting from the center and working out to the edges (preheating along the way).

Am I over thinking this whole thing? This is just much larger than I have welded before and I don't want my work to fail as a truck is driving over it.

[Ocular Engineer]

ARRGGGG! the damn puter just ate the really long reply I just typed.
Summary:
valley to fill w/ weld is ground out to 3/4" x 3/8"
using 7024, 1/8" rod
tested at 175 to 195 amps, good results and filled the V.
Planning on preheating the weld area.
Weld plan is to weld 3, 6" beads (center & each end)
Flip plate over and weld other side from the center out to each edge.
Flip plate back over and finish the first side.

Am I over thinking this?

Should I just tack the ends and run from one edge to the other?

---------- Post added 03-09-2010 at 07:14 PM ----------

well look at that, it did post.

[Freddytk421]

I have never used 7024 rods before. I have welded 1"thick plate though. I used a 6010 for the root pass and filled it with 7018. I did it all from the beveled side and didn't weld the other side at all. Warping is not going to be much of a problem but if you are worried about it you could lay your root pass and one or two filler passes then put it on a couple of I-beam about a foot apart on either side of the weld.(like a deadly teeter totter ) the tension will keep the side from bowing up although they probably won't anyway. You can weld stitches up and down it in different places to keep the heat from gathering in one spot to be safe but I wouldn't worry about welding the bottom side. You will be fine it's easier to keep giant slabs of metal like that from warping much if at all. plus thats a small valley

[Freddytk421]

Oh and if you go the deadly teeter totter route put some blocks down on either side in a few places incase someone sticks something under it they don't want to get squished.

[Ocular Engineer]

Oh and if you go the deadly teeter totter route put some blocks down on either side in a few places incase someone sticks something under it they don't want to get squished.

I'll get a pic as soon as the battery gets charged, but a couple of things:
1. the plates are prepped the same on both sides. Each side has a valley that is 3/4" x 3/8" .
2. I'll be using some larger angle, c-clamped to both plates to line up the weld seam & maybe help w/ any warpage.

Thanks for the input. I might run a small bead deep in the valley & then put a pass over the top.

[Freddytk421]

Just out of curiosity can you tell us how many hours it takes to get it all squared away when you are done including your off the clock work, consumables,extra labor from helpers and other expenses? Sometimes its better, faster and cheaper to just buy a new plate.

[Kiwimike]

When you set your plates up, leave about a 1/8" gap between them, tack weld them about every 6", then turn the amps up and make sure your root run has plenty of penetration and you will see this by the undercut in either side of the material.
Clean out the root run with a needle gun and wire brush making sure it is spotless before turning the amps back down and laying some decent size fillets.
With 1" plate you may run 3-4 times on each side, so find a nice sheltered place to work and get comfortable as you are going to be there for a while.
With trucks running over it, you may not need to worry about warpage too much.
I guess the seam will be running in the same direction as the trucks will be backing onto it. If not, you may want to gusset the underside of the plate with something substantial.

[Ocular Engineer]

Just out of curiosity can you tell us how many hours it takes to get it all squared away when you are done including your off the clock work, consumables,extra labor from helpers and other expenses? Sometimes its better, faster and cheaper to just buy a new plate.

laughingicon Stop it! Stop making sense! That isn't allowed around here! headbangerheadbanger
I've already discussed that w/ the chief engineer that I work with. This is the: "he is already on the payroll" and "no money out of pocket" solution coming from management.
But as of right now I have about 6 or 7 hours into the project. Materials are already in stock. Helpers are paid for too.
When it is all said and done, the company will have paid for two or three new 4' x 8' plates in the cost of my labor. But it all pays the same for me.

When you set your plates up, leave about a 1/8" gap between them, tack weld them about every 6", then turn the amps up and make sure your root run has plenty of penetration and you will see this by the undercut in either side of the material.
Clean out the root run with a needle gun and wire brush making sure it is spotless before turning the amps back down and laying some decent size fillets.
With 1" plate you may run 3-4 times on each side, so find a nice sheltered place to work and get comfortable as you are going to be there for a while.
With trucks running over it, you may not need to worry about warpage too much.
I guess the seam will be running in the same direction as the trucks will be backing onto it. If not, you may want to gusset the underside of the plate with something substantial.

1/8" gap, tack every 6", root pass then more; check.

A couple more questions about your suggestions:
1. On the root pass: 7018, 3/32" or 6011, 1/16"?
2. I'm pretty sure that I could make the one pass over the root pass w/ the 7024. Is that a bad idea? Should I turn the head down a little and make 2 or 3 passes?
3. Is the preheat idea a waste of time? Should I even bother w/ that?

Yes, the direction of travel of the trucks should be parallel w/ the weld. And the plate will be sitting on between two flat surfaces, so no gusset is possible.

Here are some pics of the prep: