Avoiding frankenstein butt welds

953 Views 15 Replies 10 Participants Last post by EEEliminator, 2 mo ago

tibalda

Discussion Starter · 2 mo ago

2

I have been trying to improve on my butt welds. I did one practice weld which was smoother to finish - but the penetration was poor (seam above the outlined weld in the picture). I improved the penetration, but ended up with the Frankenstein weld caused by the shrinkage right around the weld that you can see in the attached pictures. I would imagine I could improve it by grinding the back and then planishing but is there something else I should be doing? I am using very high temp and quick tacks. I could have waited a little longer between tacks and will try that in my next practice session. I don't see warpage once you get passed the immediate area around the weld.

Thanks,
Art

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1 - 16 of 16 Posts

55wagoncrazy

· #2 · 2 mo ago

Having a larger gap between the 2 pcs is better for penetration with a mig welder. Warping is part of the process. Only taking your time
and experience will improve this. To expect the weld to be flat and not warp the metal is never going to happen. It is just the way it is.

Something that helps is to back up the weld to a flat strip of copper. I took a section of 1/2 inch copper pipe and smashed it flat.
Now when ever I have access to the back of a weld, I put the flat copper strip there and it helps 100% to control the heat that
would normally wrap the metal.

Reactions: 1

hotrodg726

· #3 · 2 mo ago

I prefer to planish then grind

55wagoncrazy

· #4 · 2 mo ago

hotrodg726 said:
I prefer to planish then grind

Most of the time, good access to do this is not available. Also for the beginner.....you can do more damage not knowing what you are doing.

Mikey

Reactions: 1

Pack_Rat

· #5 · 2 mo ago

Something to strive for in your practice weld is being more consistent. You have small and large tacks and some are above the joint. some are on the joint, and some are below the joint.

When I'm welding in a panel I will touch one edge of the nozzle to the metal. I position myself so I can see the tail of the wire sticking out and aim it right at or even touching the joint.

Mikey's copper backing trick is one I use myself when I can.

tibalda

Discussion Starter · #6 · 2 mo ago

55wagoncrazy said:
Having a larger gap between the 2 pcs is better for penetration with a mig welder. Warping is part of the process. Only taking your time
and experience will improve this. To expect the weld to be flat and not warp the metal is never going to happen. It is just the way it is.

Something that helps is to back up the weld to a flat strip of copper. I took a section of 1/2 inch copper pipe and smashed it flat.
Now when ever I have access to the back of a weld, I put the flat copper strip there and it helps 100% to control the heat that
would normally wrap the metal.

That is something I didn't hear about to control warping. Thinking about my door fix - I have some sheet copper I can cut into a strip and hold on the back of the panel when I weld it. Does that sound like it will help. So the picture I showed doesn't mean I am doing something horribly wrong?

Thanks for your help.
Art

tibalda

Discussion Starter · #7 · 2 mo ago

Pack_Rat said:
Something to strive for in your practice weld is being more consistent. You have small and large tacks and some are above the joint. some are on the joint, and some are below the joint.

When I'm welding in a panel I will touch one edge of the nozzle to the metal. I position myself so I can see the tail of the wire sticking out and aim it right at or even touching the joint.

Mikey's copper backing trick is one I use myself when I can.

I was cursing to myself pretty loudly when I found myself going off the seam. I had a tight seam since I just cut the metal and welded it back so it was tough to find it - especially with the build up of carbon. I will brush off the carbon more often and need to get a better view of where the wire hits the seam. I thought I could judge based on the angle of the torch - but clearly I don't have that skill.

I am struggling a bit with the consistency. There are times that I feel I am holding the torch the same and pulling the trigger for the same time yet the result is a little different. Not sure yet why - but hope practice will help. I know one thing I need to improve on is making sure the torch is held steady when I release the trigger before I pull the torch away. At times I find the wire growing quite long which I believe is me pulling the torch away before releasing the trigger. I did tighten the spool a bit today as I was wondering if it could have been too loose and releasing the wire inconsistently.

Thanks.
Art

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tibalda

Discussion Starter · #8 · 2 mo ago

55wagoncrazy said:
Most of the time, good access to do this is not available. Also for the beginner.....you can do more damage not knowing what you are doing.

Mikey

As a beginner I can say one thing with confidence is I don't know what I am doing

- so I guess I will stay away from doing that then.
Thanks.

Shadetree55

· #9 · 2 mo ago

tibalda said:
I was cursing to myself pretty loudly when I found myself going off the seam. I had a tight seam since I just cut the metal and welded it back so it was tough to find it - especially with the build up of carbon. I will brush off the carbon more often and need to get a better view of where the wire hits the seam. I thought I could judge based on the angle of the torch - but clearly I don't have that skill.

I am struggling a bit with the consistency. There are times that I feel I am holding the torch the same and pulling the trigger for the same time yet the result is a little different. Not sure yet why - but hope practice will help. I know one thing I need to improve on is making sure the torch is held steady when I release the trigger before I pull the torch away. At times I find the wire growing quite long which I believe is me pulling the torch away before releasing the trigger. I did tighten the spool a bit today as I was wondering if it could have been too loose and releasing the wire inconsistently.

Thanks.
Art

are you bracing your welding hand any or are you just trying to free hand it?

ETriggs

· #10 · 2 mo ago

Get some 20 gauge sheet metal to practice on. When you can dot weld it together and still have it flat, you’re good to go.

Reactions: 1

tibalda

Discussion Starter · #11 · 2 mo ago

Shadetree55 said:
are you bracing your welding hand any or are you just trying to free hand it?

I do brace my hand. I am not steady enough to try with one.

Reactions: 1

copymutt

· #12 · 2 mo ago

See that little bead at the business end of your wire, cut it off. Initiate w/ a contact of the wire diameter. Leads to a consistent repetitive weld.
Wear cheaters or 2x under your helmet.
Attach a good narrow beam flashlight to your helmet pointed at the seam.
Both of these will keep you on the seam.
My issue is I get rusty between projects & need to practice up every time.

Reactions: 3

Pack_Rat

· #13 · 2 mo ago

tibalda said:
I know one thing I need to improve on is making sure the torch is held steady when I release the trigger before I pull the torch away. At times I find the wire growing quite long which I believe is me pulling the torch away before releasing the trigger. I did tighten the spool a bit today as I was wondering if it could have been too loose and releasing the wire inconsistently.

Thanks.
Art

Try leaving the cone of the torch resting on the metal at an angle so you can see the wire and pulling the trigger just long enough to get a good tack, don't pull away. Now let that tack cool fully and move the torch to a spot for the next tack. Do as Copymutt says and trim the bead off after each tack, I think it will help you to aim the wire where you want it to go, and make it easier to get a nice tack.

The cone should be touching right on the seam and the wire aiming right at the seam so you aren't welding from the side, if that makes sense.

Ernie

Reactions: 1

rodknck

· #14 · 2 mo ago

55wagoncrazy said:
Most of the time, good access to do this is not available. Also for the beginner.....you can do more damage not knowing what you are doing.

Mikey

I totally agree with this. Being a novice, the first Quarter patch in the 56 is ugly. I tried to fix it, but because of access problems it seems to be just getting worse. Since it will be a driver and nothing close to a show car.I decided to stop and just use some good filler to cover it. That quarter has been abused over the years and it probably should have been replaced, but I could not find a good one in my area when I was starting to patch it back together. Best advice from me is GO SLOW. If you rush it it will be much harder to get smooth.

Reactions: 1

mrzigzag

· #15 · 2 mo ago

One other aspect I have learned but not fully master yet is to point the gun away from from previous tack.
This way I get less grinding and better penetration and often less heat shrinking also but it took some time to get it going. When I started I always welded against previous tack just becouse it was easier, but the result was worse and 10 times more grinding

Only when I have a wider gap that I need to fill I point the gun towards the previous tack to have more material to absorb the heat better

Reactions: 1

EEEliminator

· #16 · 2 mo ago

Not an expert, just started patching some sheet metal on my trans tunnel butt welding them in. I saw a technique on youtube using compressed air from a blow gun on each weld, you have to get to the air pretty quick but not too quick or you'll blow the molten metal out. You have to have your welder setup dialed otherwise you'll still get big cold welds without penetration or blow through. It seems to work pretty well from my limited experience.

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