BIG JOINT...little welder

lastcowboy32

Well-known Member
I posted some questions about this project a week ago. I have my pieces cut and mostly coped out with fishmouth cuts. Right now, I'm at the point where I'm starting to weld up some of the frame.

I have 4 inch diameter tubing with 1/8" wall thickness. I need to make some perpendicular "fishmouth" joints with this. I welded a test joint at the end of a piece, so I could look into the end and see the penetration. I'm not in love with it. My little wire-feed welder is supposed to be able to weld up to 3/16." This tubing is 1/8" thick.

I took a scrap piece of tubing and laid a bead on it, indeed the welder could blow right through; if I sat on one spot too long.

However, when I butt two pieces together with one of these fishmouth joints; there is no way that I can lay a bead in the joint and penetrate both pieces. I'm wondering if that's because that would be equivalent to welding 1/4" material?

The only spot on my test joint that showed penetration was a spot where I welded by concentrating on the parent piece (not the fishmouth). I laid a bead right onto that, which built up toward the fishmouth piece. It then took two more beads to fill the joint. The last bead did seem to complete the fill of the joint by melting the previous bead and the end of the fishmouthed pipe.

Is that a good way to make a big joint with a little wire welder?

Would preheating with a torch make things better?

I have some pictures showing an example of a dry joint before final grinding to cope and a welded test joint.

Note that there is galvanization involved. I grind all galvanizing off before welding...I do that outside with a respirator...so I'm OK with that. It's strictly the joint size that's bugging me up.
35374.jpg
35375.jpg
35376.jpg
 
Doesn't look like you got much penetration of the weld. I wouldn't trust it if it's in a critical spot.
 
Looks like you don't have enough welder to do the job. When welding a joint like that I would be running a Cresent pattern bead also. The Cressent pattern will fill better and concentrate more heat for penetration into the joint.
Loren
 
Cold weld. If it were me I would work on the fit first. It needs to be much better for a decent looking weld. Crank up the heat and pattern your weld to spread that heat. A straight run ain't gonna work with what you have.
 
That's what I was thinking. I need a little better fit, and I need to figure out how to get better penetration into the two pieces.
 
Hi, If this is for that cherry picker your building, I hope your life insurance is paid up!
not near enough heat and penetration to weld that pipe. Sorry, I'm not trying to be critical
but I don't want to see anybody get hurt.....Jim in N.M.
 
Yes, I didn't like the test weld either. I'm not getting under anything that doesn't have good, penetrating welds. I have a few tips here to try. I'm also thinking that I should look at perhaps putting an extra piece of metal on the parent pipe. If I took some of the scrap cutoffs and made sort of "band aids" that go on the parent pipe, with a hole cut in the fishmouth, then I could weld the band aid to the parent pipe; and the fishmouth would sit down into that bandaid...essentially making the weld more like welding in a V or a crotch than the way it is now.

The way the fishmouths mate with the parent and the thickness of both pieces make the dry fit a very crappy way to start a weld, unless you have some serious welding power that can just blast through both pieces.

I could buy an engine hoist. This project was supposed to use some materials that I have, while being a good experience.

It doesn't do me any good to gain experience, if I kill myself in the process.

Thank you sincerely for your concern.
 

From what I see in your pics I would try holding the "stinger" so that it is a little closer to perpendicular to the uncut piece in order for more of the heat to go into it.
 
Looks like maybe you are just moving a little too fast. Try slowing the progress a little, make a stitching
pattern across the gap, moving as the gap is filled.
 
Fit up could be a little better but its not that bad. Why cant you feed into the joint better? I would grind that bead down and start over feeding the wire right into the joint. Don't favor the one pipe ,make the joint. Your prep up could be ground cleaner. Ideally you would arc weld with 7018.The bead is up on one pipe because that's where you placed it , get into the joint.
 
Fit the pieces to reduce the gap. If your wire welder is a 110 volt, I think that is part of the problem. They"re usually overrated as to what thickness they can weld.
 
Hi Just a question about your "Wire feed" welder Is it one of those $100 gas less junk welders from our buddys at HF or one of those 135 type
Lincolns. if so you will have problems welding that pipe right. I got a 150 amp 220v wire feed thats got gas on it that would stick that crane
together and it's not coming apart it's about 25 years old.

We had a new Lincoln 120 volt gas less at work it was the most useless piece of junk a guy could buy. I wanted to run it over while i worked there,
my replacement actually did after i left. Both of us are good welders with wire feed and stick and neither of us could get it to weld right.

If this is your first project and an engine crane, I'd be a little less ambitious until you know more about welding/ have a better welder, or maybe
get a professional to do this one. As you are starting to realize from what others said this needs to be right. even with my experience certain
things go to the certified welding shop in town if it's a customer job i'm working on like highway trailer hitches.
Regards Robert
 
If were to preheat the joint with a torch
to almost red hot and turn your welder all
the way up you can get by with a small
welder on some job's
 
(quoted from post at 19:05:54 04/25/16) Hi Just a question about your "Wire feed" welder Is it one of those $100 gas less junk welders from our buddys at HF or one of those 135 type
Lincolns. if so you will have problems welding that pipe right. I got a 150 amp 220v wire feed thats got gas on it that would stick that crane
together and it's not coming apart it's about 25 years old.

We had a new Lincoln 120 volt gas less at work it was the most useless piece of junk a guy could buy. I wanted to run it over while i worked there,
my replacement actually did after i left. Both of us are good welders with wire feed and stick and neither of us could get it to weld right.

If this is your first project and an engine crane, I'd be a little less ambitious until you know more about welding/ have a better welder, or maybe
get a professional to do this one. As you are starting to realize from what others said this needs to be right. even with my experience certain
things go to the certified welding shop in town if it's a customer job i'm working on like highway trailer hitches.
Regards Robert


You're right on the money. El Cheapo HF welder. This isn't my first project. I've been learning with this welder for about a year now.

I've learned to critique my work; and on the right size metal with good fitups, I can lay some good beads with this welder.

This project is a little more ambitious, and I want to make sure that the beads are right. I'm wondering if I'm at the limits of this little guy, and I should graduate to something better, or if I could change my technique a little and get by, or if I should consider using my oxy-acetylene rig to gas weld this with filler rod.

Either way, nothing is moving forward with this project until I'm satisfied that I can weld a good joint on this material.
 
So, I ground down that cold bead to turn the joint back into a V.

I then tried applying a weave bead, which was described to me as sort of a walking triangle. Start in the root of the joint, up one wall just a touch, back across to the other wall, back down to the root maybe half a bead forward. Repeat, repeat, repeat.

The welder's instructions say that 1/8" material should use maximum power and maximum wire feed speed. That's what I've been trying all along. In one picture, you'll see my finger pointing at a crappy section of the new bead. Here's what's odd: with the wire set at maximum feed rate, my weave bead just sort of piled up in the joint without really biting into either side.

I tried intuition over instructions and turned the wire feed down by about 1/3. The welding sounded more smooth, less sputtering; and it seemed as though there was time to truly melt the wire into the sides of the joint as I was weaving. It actually came out nice. (not counting that first spot with the wire feed too fast) I completed about 1/3 of the way around the pipe and looked inside the mating piece. Nice. I see an arc of discoloration in the shape of the mating pipe and evidence of penetration all of the way through.

With this fishmouth joint, it does seem like the method needs to be modified from doing, say, a deep butt joint that's been
V notched. I can't start exactly in the root of the joint. The surface of the non-fishmouthed piece is round, and the wire will deflect , instead of staying right in the joint. It seems like I have to pick a side to aim at initially and then only start weaving the bead once the puddle is started. There is also only so much gap that I can cover. When I ground out the old weld, I made part of the joint have a gap. In that spot, I had to keep the weave bead right on the main pipe without crossing the gap completely. Then I came back, chipped, wire brushed and did another weave bead to completely get across and penetrate both sides.

When I get some more time, I'm going to finish the rest of the way around this test piece and see if I still like it.

35448.jpg
35449.jpg
35450.jpg
35451.jpg
35452.jpg
 
The HF brand may not put out what it is rated for. a neighbor has one and it seems weak. Try not to use an extension cord or if you do make it a big one. Turn heat up all the way and as you were doing adjust the wire speed when welding so it is a constant buzzing sound. Some say the proper sound is like mad bees, others say like bacon frying. A 110 volt machine will not weld fast, travel speed needs to be pretty slow. Using flux core wire drag the puddle. I use a small Lincoln in the field for handrail repairs, gates, etc. with flux core wire. It works fine for that. In the shop I use a larger 220 volt with gas.
 

I can relate to what you're saying. Things go better when the welder just sounds right. Dragging the puddle also seems to work better.

Since the wire is being pushed out, it also seems that tip orientation is important. If there is any little gap between the pipes; and you aim towards the gap, you're screwed. the wire will push through.

I made a little diagram :)

It seems that the wire needed to be aimed at the main pipe perpendicularly to make sure that it hit straight, penetrated and formed a puddle. I could only "weave" the bead over to the fishmouth pipe by ensuring that the puddle spanned the gap, if there was any and then trying to rotate the orientation of the tip to make the wire hit the other side of the joint in perpendicular fashion.

It would probably be easier with a big old stick welder that uses larger diameter rod and makes a bigger puddle. A stick also won't try to push through any little gaps. It stays where you hold it.

35453.jpg
 

What kind of gas do you use for just everyday iron, pipe and things like that. Do you need Argon? CO2? a mix? I'm curious. I mean...I already have to go to the welding supply to get gas for my torches....If I considered getting a gas welder, how much is gas going to cost me to get started?
 
Gas makes for a cleaner weld. Not nearly as much splatter. Solid wire used with gas does not penetrate as well as flux core. You definitely need a 220 volt machine. I use the large cylinders of 75/25 mix. It is about $40 for a refill. Straight CO2 is cheaper but gives a little more splatter. Since most of my work is ornamental fencing, gates, furniture, and such minimal clean up is important to me as a time saver.
 
(quoted from post at 17:19:04 04/26/16) Gas makes for a cleaner weld. Not nearly as much splatter. Solid wire used with gas does not penetrate as well as flux core. You definitely need a 220 volt machine. I use the large cylinders of 75/25 mix. It is about $40 for a refill. Straight CO2 is cheaper but gives a little more splatter. Since most of my work is ornamental fencing, gates, furniture, and such minimal clean up is important to me as a time saver.

Thanks
 
I see a lot of good advice in the comments below. I will add one more piece of advice when welding pipe. ALWAYS triple pass. I.E. you have your initial weld in the joint. Second pass lay a penetrating bead that bridges the bottom of the initial weld and into the pipe. Third bead same as second but bridging from above the initial weld into the pipe above the initial weld. This is done for additional strength and helps assure good penetration all the way around the joint in multiple layers. Good luck and have patience.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top