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Need advice on butt welding 1" plate steel



Ocular Engineer
03-08-2010, 08:43 PM
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
03-09-2010, 05:41 PM
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
03-09-2010, 06:06 PM
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
03-09-2010, 06:14 PM
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
03-09-2010, 07:03 PM
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
03-09-2010, 07:17 PM
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
03-09-2010, 07:29 PM
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
03-09-2010, 09:14 PM
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
03-10-2010, 04:21 AM
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
03-10-2010, 06:24 AM
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:
http://i214.photobucket.com/albums/cc262/mrk66/Delta%20Mariner/P3100011.jpg

http://i214.photobucket.com/albums/cc262/mrk66/Delta%20Mariner/P3100012.jpg

Hamstn
03-10-2010, 08:21 AM
I would bevel the edge down a bit more so the edges of the two pieces are 1/8" thick or less. You can use a steeper angle so it is just wide enough to get the rod down there. You will be sure to get full penetration this way. Weld the vertical part of the ends with it clamped down to help hold level. Run a root on both sides and clean out. Now take the piece and angle it say 30 degrees and start at the bottom moving up hill. This will allow the slag to flow down and away from puddle helping keep out intrusions. Alternate between the sides as you make each pass. As your bevel gets wider towards the top increase your figure 8 or "C" pattern. You may also have to lower the angle of the piece so your puddle does not want to flow down hill.

I've done this several times with material 1 1/2 to 2" thick like a draw bar on a tractor.

Not sure if it is right or wrong but I use 7018 only. It is just not a deep penetrating rod so the reason to bevel down to a thin edge.

Kiwimike
03-10-2010, 07:50 PM
Hamstn is right, bevel your plates to more of an angle.
Weld a root run on both sides after cleaning each run well.
I would use low hydrogen rods without preheating and use as many runs as it takes making sure the last run caps the other welds.
I'm glad the Engineer had some common sense over this project, as so many will over engineer something just to save their butts.

Ocular Engineer
03-14-2010, 04:31 PM
I just wanted to thank you guys for the tips and advice. I finished the welding yesterday. The plate is reasonable flat (probably 3/8" cup to it). Flat enough to drive trucks over anyway. I'm confident that it will hold together.

If it doesn't, it has my 50/50 guarentee. If it breaks, they can have both halves.

Thanks again guys.

SICFabrications
07-27-2010, 07:49 PM
i have to splice alot of bridge parts together using 1 to 1 1/2 plate grade 50 steel.... the way that i have to do this is this (procedure) make a 22.5 angle on both sides all the way to the bottom. tack a backing bar in place (just like a groove test coupon) and start with 7010 or 71t-1/ t-9 seismic duo-shield wire run a few passes, then switch over to 8018 rods (or still running the same FCAW wire) once the weld is proud, flip the plates over and back gouge the weld until about more than 70 percent through the metal (basically, open the weld up from the other side) and create another bevel and fill er up again, this time using only the 8018 rods (because the root is already done) using a steady preheat to maintain temp and inter-pass temps....

that is bridge code, prolly not needed for something a truck drives over.... wait.... you drive over bridges too...hmmm....

Ocular Engineer
07-28-2010, 07:22 AM
My eyes crossed and I actually got dizzy about 1/2 way through your post. laughingicon

I completed this project a not long after I started the thread on it. I happened to take a look at the completed and used welded plate about a week ago. It appears to be holding up, but I don't know how much action it has seen.

My welding procedure was a little simpler: +/- 45 deg bevel on each corner, 6011 root pass on each side followed by 2 or 3 more passes on each side of 7014, alternating sides of the plate to control the warpage.

...and besides, when people talk about me being a "welder" I tell them that I can stick two pieces of metal together that will probably stay that way forever, but I wouldn't call myself a welder.

SICFabrications
07-28-2010, 08:48 AM
lol... No worries, was only trying to convey coded procedure for load bearing welded splices... When i get home this weekend, i will try and type out a more discernable procedure and some pics to help...

Buckcp
08-17-2010, 08:35 AM
Sicf, I always know if your answering a question I'm going to get great information. Sure glad your on this site and sharing your knowledge with us. Thanks

SICFabrications
08-17-2010, 06:29 PM
Sicf, I always know if your answering a question I'm going to get great information. Sure glad your on this site and sharing your knowledge with us. Thanks

thanks for that, buck.... and i forgot to rewrite procedure for this in an understandable manner..... ima try to do that now

---------- Post added at 07:29 PM ---------- Previous post was at 07:04 PM ----------

i'll have to do this without pics, so i apologize.... and i will explain this as if it was being done SMAW only, just for ease and clarity....

if you were to take a skill saw and set the blade angled to 22.5 degrees and cut through the plates, you would end up with two pieces beveled.... flip one over, and you have a 22.5 "v" groove... (i think that explained the bevel)

now, when you set the pieces up to be welded, space them apart where the points of the bevel are 1/4 inch apart from each other, now, take another peice of metal 3/8 thick and slide under the joint (backing bar) and tack it into place on the back side, you dont want tacks inside the groove...

making your first pass (root) with 6p or 7010 rod, make the pass letting the puddle tie in both pieces, knocking the edges off the bevels on both sides and burning into the backing bar...

clean weld with a thin grinder stone, careful to not cut too far into the weld, just to knock the ridges and slag off the root weld..... now comes the hot laps and fill... using a low-hydrogen rod (7018, 8018, 9018 etc...) start making subsequent passes, making sure to melt into the welds underneath, and fill that groove up until almost flush.... make sure to clean in between each pass with a stringer brush on a grinder...

now that you have "flushed" the weld, now comes the cap and stringer passes.... the cap pass(es) should be weaved side to side about the width of the rod, and make subsequent passes until the weld is a little higher than the base metal... now stringers....... no weave pass on both sides of the weld to tie the weave in, (weaves sometimes will leave cold laps)

now comes the fun part...... flip it over.....

using carbon arc gouging (the oxy fuel torch leaves too much oxidized metal, so you cant (shouldnt) use a torch for this.... cut the backing bar off and gouge down into the weld creating a groove into the backside until you are about 70% into the joint..... grind it smooth and bevel again with the grinder...

repeat process, only this time, using only the low hydrogen rods..... once you have filled the welds, and the weld is proud( sitting above the parent metal), the grind it smooth, flip it over and grind it smooth there as well

after all this trouble, what you have ended up with is a perfectly welded joint on some heavy metal, this is what i have to do with each and every bridge part that comes through my shop.....woooooooha!!!

the real fun part is when you have to hand weld nelson studs onto a splicer plate...talk about boring