I have an up coming project that has pass throughs. While practicing i had one go wonky. One side of the bar went out of alignment with the other. The slot was center nicely when i cut, even swell on both sides, the flaw happened while upsetting to open the slot to get my drift in. I know where i made my mistake when upsetting, to much hot bar. I fixed using a combination of swage block, hardy hole, etc., etc. just working it a little at the time till it was acceptable, not perfect but acceptable. I see it still but most wont. The problem was it took me about 2 1/2 hours and many, many heats and spot cooling. 

Since i got the bar "fixed" here is an illustration of my problem. Excuse my crappy drawing skills, but the one on the left is how it should come out and the one on the right shows how the bar drifted to one side. 

So does anyone know of a quick easy way to fix this? 

No I don't know the easy way, but seeing your query brings to mind that Jennifer (JLP Svcs) has commented about this problem and her solution which was related to differential heating. I'm sorry that I do not have a link but I think it may have been in one of her videos.

--Larry

The "easy" method is to get another bar and do another. Seriously I'd do what you did, lots of heat and adjust as I go till it was right. If it were a round hole you can drive the hole where you want it within reason. Use your bar that fits the hole, and either drive the drifted bar from the thick side, truing it regularly. Or you can put the round bar in a vise or open the vise so the drifted swell bridges the jaws and using a block of wood and large hammer bump the bulge towards the thin (bottom) side, re-drift and refine.

There are as many ways to adjust a drifted bar as there are smiths who do it.

Frosty The Lucky.

The problem is quite hard to explain, i should have taken a pic before i fixed it. But i am not trying to move the hole i am trying to move the bar next to the hole. If i move the hole then the other side of the bar where it meets the swell goes off center. 

The project will be 5 pass throughs in 1" x 1/2" bar. If i start over with new bar that could get quite pricey. 

Frosty, yup. I would say there are more ways to do it than there are smiths doing. Like has been said ask 100 smiths why you will get 500 answers. 

I think i figured out most of my problem yesterday though. My practice bar is 5/8". While working yesterday i slit my hole and ended up with an almost perfect 7/16" square hole after upsetting. I think that i need to make a new slitter just a bit wider than i have and my upset will get very close to the 1/2" i am wanting with very little drifting and using the larger bar will also help greatly  think. Trying to make a 1/2" pass through in 5/8" may be just that there is so little material on the sides it is difficult to do. 

When i get to work tomorrow i will do the the math and figure out how big the swells will be and mill me a jig that to align the bar with and hope it will work in either a vice or my press. Not a forging press i have a 12 ton hydraulic, the kind that is basically just a bottle jack on a frame.  

Good Morning Billy,

I asked Francis Whittaker one time, "How do you punch a hole and keep it at the angle you need/want?". He looked at me and with a little smile/smirk, he answered "You drill a small pilot hole at the angle you want." 

The same thing happens when punching a Bar. Make a guide, so you stay on center. The human eye and brain can see something not centered, from a distance. If you have a bunch of holes all off-center, the human mind and eye accepts it. The Fabricator must be on Center, the Artist is allowed to venture off center.

Neil 

So, it was slit, then upset from the ends to open the slit to a semi-square shape before applying the drift, and it went off to one side?

Were it me, I would try to upset as much as needed for the piece before drifting (except that it will always spread wider when drifting) then use a more tapered drift or two drifts if needed, one to open the slit and one for the final shape. You can also upset a bit with the drift in as suggested above by Frosty and move holes and the material around them a bit; sometimes its easier if you apply the heat more to one side - the metal moves more where it's hot.

Upsetting can get finicky and go off to one side pretty easily if anything is a little off center, more so if there's a hole involved. I've taken to doing more of it with isolated heat and a floor anvil when I can. I seem to have it go wonky less often. Picked it up after I saw a smith I liked making the swells for bamboo in metal pipe with a floor anvil.

Okay, this is starting to come back to me.

How did you mark center on your stock?

What shape slitting chisel did you use? Is the edge straight . . . or?

What did you use to open the slit BEFORE upsetting?

If you didn't open the slit before upsetting then what guided the sides to move where you wanted them to? 

If the sides of the slit were a TINY bit different it WILL upset towards the thinner half, bending.

And there you are, an off center hole sometimes tilted.

I use a Brian Brazeal "Slitter" it'd take a real stretch of the imagination to see a chisel. His slitter has a pointed edge at approx. 30* angle to rounded ends. The faces of the blade are obtuse compared to a hot chisel. The the slitter blade is slightly thicker up the center.

I scribe the centerline of the stock, reversing the dividers to mark "exact" center. If the dividers are slightly off, reversing the dividers and scribing again from the other side of the bar WILL make two scribe marks. The exact center is midway between them. Make sense?

Now gently center punch the ends and center of your intended slit.

Bring the stock to heat, place the slitter in the center punch mark and align it with the line and give it a light blow, check the effect and correct if it's off and proceed

When you feel the anvil with the punch, there are both tactile and audible cues. Turn the bar over, the center of the slit will be a spot with ghost lines pointing down the center of the stock. Carefully place the point of the slitter in the center mark aligned with the lines and it will follow the first half of the slit. 

Drive it through over the hardy and it will start the slit open slightly more wide in the center. 

I open the slit with an old chisel I rounded, narrow on the edges and thicker in the center and drive it a BIT more than 1/2 way through, flip the stock and drive it through. Then I drift to size and shape.

The few times I've tried upsetting a slot it didn't go near right so I went back to what I know.

Of course that's just me I could be wrong.

Frosty The Lucky.

Finding center is no problem, i use a center scribe. Sort of like a carpenters center finder but much more precise. 

My slitter is exactly as you describe but with a bit less angle on the business end. Also inspired by Brian Brezeal.  It is as true as you can ask for after 5 or 6 years of use and being resharpened, reshaped from mishaps, etc. At its widest maybe 5/16", a 1/4" drift slides through but a 3/8" wont. 

So, i score the top and bottom on center, center punch the top and bottom (again i have no problem getting my center punch marks in the correct location) Then cold with a small chisel lightly set a groove i can see hot, mostly just to make sure my slitter is on center line, heat it up, slit, turn, slit, flip, slit, turn, slit, repeat. (Same technique i use making banana trees. They loop up and over then through the bar with the hook to hang bananas on. Those i do not upset and just drift open and round holes.) Then a small slot punch to open up a bit. Upset the hole, then drift to size. I may add my slot punches are just old chisels with the end ground flat and the corners rounded. 

Nobody, I keep a 6" cube of 4140 on the floor next to my anvil for upsetting. These are practice so i was using 6" or 8" pieces i had lying about. 

From what i am gathering is that there is no quick and easy way to correct the mistake. Just take my time, move the metal bit by bit using a combination of spot heating and cooling. 

 

A bit late to the party here, but I see what you are trying to fix, and the only "easy" way I know to do this is to make and use top and bottom tooling to straighten the bar perpendicular to the drift. 

Otto Schmirler's book has an illustration, IIRC.  

I forgot to check my Schmirler book this week, but maybe it was from Mark Aspery's book #3 in the pass-through ring project...I'll try to remember to check today, but no guarantees.

This one?

Yeah, who doesn't have racks full of closed die type top and bottom tooling? Are there directions on how to make that kind of specialty tooling? 

Frosty The Lucky.

12 hours ago, JHCC said:

This one?

That's the one I was thinking of.  Thanks for covering for me, it was a long week in the shop with new members...

Teamwork makes the dream work!