t joint weld prep

[Gary Fowler]

I would think that if you follow the sketch on the attachment thread with all the gussets on it, a 1/4" fillet would be sufficient. If you bevel the plates so you get at least half the thickness ( 1/3 on each side and 1/3 unbevelled) then top with 3/8 fillet weld, it will never break if the weld is solid. If you can weld it flat or slightly inclined, E 7018 in either 3/32 or 1/8" size will work in the tombstone Lincoln. About 125-150 amps should weld good in flat or slightly inclined uphill for the 7018 works best for beginner welders.. I would use the 6011 as a first pass then fill it and cap with the 7018. They are stronger and more ductile than the 60xx series rods. Just keep as short an arc as possible without them sticking. Get the AC version of the 7018 for your crackerbox welder. The tombstone welders like to run a longer arc to avoid the rod sticking which makes it aggravating somewhat with the 7018 as they need a short arc length to weld properly but the 7018AC helps with that. I have used hundreds of pounds of DC 7018 with Lincoln Tombstone welders back in 60's and 70's when all I had was the AC machine and 7018 AC was not made yet and other than hard to start and occassionally arcing out, the weld was strong. I even welded cast steel and stainless steel with them with good results although the welds would rust on the stainless.

 

[swick1]

Success!!! The wiring at the breaker was 110v. I changed it aroumd and now it really cooks! I still could use a 50 amp breaker though because it is tripping every half rod at 150 amps.

 

[kaferhaus]

Success!!! The wiring at the breaker was 110v. I changed it aroumd and now it really cooks! I still could use a 50 amp breaker though because it is tripping every half rod at 150 amps.

That machine is supposed to be on a 50amp circuit... with the appropriate sized wire from breaker to outlet of course.

I agree with the 6011 root and 7018 filler. BUT if you don't have 6011 or 6010 for a root pass 7018 will give a good result on it's own.

I'd use 5/32 rods... but you could get away with 1/8 if you work them right.

 

[Tractor Seabee]

It's all about the stress placed on the end product. 1" attached to 1/2" material, the joint will be no stronger than the 1/2" plate the 1" Ts into. Piling a lot of filler on top of a well filled fillet adds nothing to the strength. In fact a fillet weld should be somewhat concave when completed with no undercut on either side. Nothing weakens a joint more than undercutting. Makes a natural path for a crack. I have used AC buzz boxes a lot. Now have an AC/DC that I only use on DC. The 6011 root pass is good info. The little drawing in one of the posts is the way I would do the bevel. If the molten puddle does not penetrate and fuse well on both sides you have a weak joint so you need to assure the heat gets down in there. If apperanace is not the goal you can take it 6011 all the way. Your metal is probably tensile rated no higher than 60,000 PSI anyway. The first to numbers are the tensile strength. The 7018 is a low hydrogen rod and makes a nice bead with little splatter and easy removed slag, pops right off, builds up fast, and is good all posistion including downhand. I disagree on it being flat work only. I use 7015 with my DC reverse. 18 is made for both AC and DCR. Amp settings? They are all only an approximation. Every machine is different with different fudge factoes. Practice and run at the highest amps you are confortable with. Only too low amps gives a bad weld all other factors equal. Higher amps it is easier to strike and maintain the arc. If your weld deposit is thicker than a dime higher than the adjacent material you are too cold. Diameter of the rod at the right heat will determine the width of the puddle unless you weave a lot. It takes a lot of practice to get a weave down pat. I use a figure 8 weave a lot for vertical work opr if I have a wide joint to fill as you can control the puddle better. There are some inexpensive manuals out there for the novices which can get you up and running fast.

Hopes this helps, from and "old" pipefitter/welder. Tractors are a lot more fun.

 

[swick1]

Thanks for the help guys. Im going to weld this weekend. I will post pics.

 

[swick1]

This is from my first weld bead. I was holding the rod too far away from the work.

 

[Gary Fowler]

Even with a slightly long arc, you shouldnt have that much porosity. Check your rods for moisture or block the wind from the welding area. Looks like you were running too cold also. You may need to go to a smaller rod if you are maxing out your breaker capacity. You have to get the amps up to the correct number for the rod you are using if you expect to get a good weld. 150 amps if correctly measured would burn a 5/32 rod but with inexperienced welders, I never recommend larger than 1/8" as the larger rods are the harder they are to use correctly.

 

[Tractor Seabee]

This is from my first weld bead. I was holding the rod too far away from the work.

Swick,

If that was done with 5/32 it is way too cold. Your 150 Amp problem is going to be a problem trying to do a 1/2" fillet (your tee word). Use 1/8 as hot as you can sustain your weld w/o tripping the breaker. I always run a little hotter than most but then I have done a lot of this. Hot, short arc, stay ahead of the puddle and don't let it pile up. Better to have a small hot puddle than a large cold one. Point your rod toward the cold metal not toward the puddle. Later you can get to where you can work it both ways depending on what you want to do. Remember you are fusing the metals, both pieces and the rod, lay it on top and you do not have a weld. I gave away all my books on welding long ago or I would send you one. You may have to go with 3/32 rod with your amp limit. It will work ok, just take a lot longer. To start, use what we call stringer beads; small beads tht overlap each other. Get that down before you try a weaving pattern. Practice on scrap till you get it down. When I first started I burned 50# of rod before the instructor gave me an A. And that did not include vertical or overhead work much less welding down hand. It is difficult to do this on the net, better if you can see the student's technique and provide guidance and corrections. Find a friend who welds well and let him (her) coach you. Too bad you are not just down the road.

Ron

 

[swick1]

I switched out my circuit wiring to 6ga and put in a 50 amp breaker. I played around some more and got a much nicer looking weld with undercut, so i'm sure that i am penetrating well. I just need to modify technique to lose the undercut. Thanks for the advice so far! I always thought you needed to point toward the puddle as you drag the rod? What does turning it the other way do?

 

[Tractor Seabee]

I switched out my circuit wiring to 6ga and put in a 50 amp breaker. I played around some more and got a much nicer looking weld with undercut, so i'm sure that i am penetrating well. I just need to modify technique to lose the undercut. Thanks for the advice so far! I always thought you needed to point toward the puddle as you drag the rod? What does turning it the other way do?

It makes sure you get the heat to the bottom of the joint, you have to hold a close arc though and move fast enough to ensure you do not blow a hole through. Look on the reverse side of the weld, if you see a nice even bead on that side you are good, if you see the gap in the joint you are not penetrating to the bottom. You need about an 1/8" gap between the two pieces. Make sure you melt in all the tacks also, you should not see where they were on the reverse side. If you leave any unfilled areas you have a weak joint. It's hard to explain but you can see the result.

The root passes ARE THE MOST IMPORTANT, they do not have to be a lot of metal or look nice, just solid and sound. The next passes as you can experience is when you point toward the puddle as you get more build up. At that stage you are not worried about burning through and leaving a void or slag pocket. Practice Practice.

Ron