Fix a crooked hole?

[Michael]

So I got my neighbor to come over and strike for me, not the strongest striker but willing. The plan was to taper a jackhammer bit and make a hammer head.  We got the bit shaped, its going to be a mandrel for the shaping the hammer head.

 

Lesson learned, I should have marked both sides of the hammer head blank before we started punching. The result, a crooked hole, centered  along the length of the blank, but leaning more towards one face than the other. Its fine from one side and offset about a half a hole on the other side.

 

I'm wondering if in the process of drifting the hole out to full size for a handle, can I bring it back into line?

 

I've got smaller drifts, 15, 13 and 11/16ths that I could drive half way thru and try to knock the hole back into line at high heat

 

 

I think these are actually tapered shafts of some sort, but they make great drifts.

 

This is the only chunk of hammer sized stock I've got at the moment.

 

I think I'll pull out the play clay, see if this problem lends itself to some visual modeling.

 

thanks.

[Steve Sells]

also remember the entire hammer head at heat is maleable, so you should be able to balance out the slanted hole. removing some metal from the one side of the hole, then flipping over and then doing the other side the same way may help get mass realigned also,  rather than just trying to move the mass from one side around to the other by only changing angle of the mandril

[easilyconfused]

Is the hole punched fully? It's hard to tell from the photo's.  If not, re-align and call the old hole a new design for ergonomics.

 

If not, you can use the drifts to create a larger hole in line but pay attention to mass if you want a balanced hammer, as Steve pointed out. You could also use the longer side to become the face of the hammer with a little more mass to the front, like a modified cutler's hammer.   

[Michael]

Thanks for the tips, the hole is all the way through, but only about a 1/2 inch wide on the off center side, that's why I was hoping I could drift it more towards center. The centered hole is just started with the long tapered drift, not even halfway thru the head yet.

 

[Rich Hale]

If I knew wot the steel was I may have a  thought,,,Withouit that you may try stock removal to get it back close and then drift with a tapered oval drift from both sides.

[clinton]

Chuck it and find more material. Maybe try slitting and drifting some smaller sized mild steel and get some practice before moving to heavier stock. I do not think you can really fix a hole like that in a reasonable amount of time. You may ruin it with too many heats.

[Timothy Miller]

When I have this problem there are two ways I know how to fix it. One you can file the hole back to center. You can also realine a hole if it is twisted. If you have a die grinder you can get the job done quicker. The other is you can push the extra metal off to one side and grind that off. If you have plenty of steel it is often faster to start over.

[tomhw]

If you need a hammer right now set this attempt aside, for salvaging at a later date, and start over.  It looks like you used a round punch.  When you drift the hole the sides will stretch thin and weaken the hammer.  In the future use a hammer eye punch.  It is an oblong punch with a flat face and a gentle taper.  Face looks sorta like ( _________).

You may get away with a drifted round hole for a hammer but for top tools and hot chisels the sides will be too thin.

[tomhw]

If you need a hammer right now set this attempt aside, for salvaging at a later date, and start over.  It looks like you used a round punch.  When you drift the hole the sides will stretch thin and weaken the hammer.  In the future use a hammer eye punch.  It is an oblong punch with a flat face and a gentle taper.  Face looks sorta like ( _________).

You may get away with a drifted round hole for a hammer but for top tools and hot chisels the sides will be too thin.

[MOblacksmith0530]

Okay like was said above the hole is too small for a hammer handle anyway. What you need is a slot not a square hole. you need to make a punch that is like a long but blunt chisel and then you can re-cut the existing hole from either side until it is centered the hole/slot should be the length you want for the finished hammer handle minus a little bit for stretch from the drift. so if your finished hammer handle is 1-1/4 bu 1/2 oval your slot should be 1-1/8 by 1/4 or something. Go to the tools section and search slitter geometry and there is a large thread there that will help you out.

Good luck.

[pkrankow]

Maybe you can use a hot chisel and make a groove in the hole where the drift needs to move to one side. When you drift the relief of the groove will cause the hole to open towards the desired side. 

 

Still might end up making a smaller hammer due to removing stock that is off balance, or a throw away and start over.

 

Phil

[billyO]

Localize the forging heat only at the portion of the eye that you need to move?

[FordPrefect]

Here is a method that will guarantee a straight hole almost every time, see this article  http://www.iforgeiron.com/topic/30265-punchingslitting-holes/, see this picture

the only thing I can add to this is that after you punch all the way to face of the anvil, but not quite trough, turn to the other side and look for a black spot about where the whole should be and start to punch from that side...

 

Also see this article: http://www.iforgeiron.com/topic/10211-slitter-geometry/

[FordPrefect]

If I missed something, Brian or someone else could add to it...

 

 

The hammer above had a crooked hole, but Brian Brazeal and Ed Brazeal and myself were able to save the hammer, it took some work but there it is, I was directing on this hammer, I held the drift crooked and that is how the hole got crooked, but I learned how to salvage it, and how not to slit a hole, a learning experience.

[VaughnT]

I'm very curious as to how the hole will be aligned after it's been drifted to proper shape (flat oval) and the cheeks have been worked down.  Having never built a hammer, I don't have the hands-on experience, but I'm thinking that a lot of the metal can be moved during the shaping process.

 

Am I wrong?

 

Another thought would be to drift the hole to the proper shape, but leave the one side a bit larger.  Basically, this is an hourglass cross section with the bottom portion wider than the top to account oopsie.  The hammer handle could easily fill this larger portion and would make for a stronger handle, too.  Does that make sense?

[Michael]

The steel is S2 according to the smith I got it from. I'm in no hurry, just wanted to try it.  I think the slitting chisel in the direction I want the hole to go is the the way to attempt to fix this. Thank you for all the info and direction, gave me a lot to think about.

[David Gaddis]

An hour-glass handle form cannot come from a drift witha sharp corner, as that is the beginning for a stress crack. The proper shape as shown prior is created from a round tapered shaft, with a bit of flattening on two sides only! The other two side will be a nice rounded shape that is perfect for spreading that eye metal.

 

The next time you make the penetration for the eye, review other threads on the proceedure. Basically it starts with a slimmer penetrator, with a well designed point, prior to going to a fatter, stronger penetrator. ALWAYS turn the piece to be penetrated 180 degrees after every few hits, or turn the penetrator 180 degrees. That turning motion helps AVERAGE out the possibility of mis-alignments.

 

perhaps you could turn that slug into a flatter, although the hammer handle will be a little bit offset. ANyway tha handle in a flatter does not require much creative geometry. It would be a good use of that S2 slug you have.

 

GOOD LUCK

 

 

carry on

[MOblacksmith0530]

Be careful of the s2 it can work harden. Make sure that when you get done forging it you anneal it in wood ash or vermiculite.

[Frank Turley]

Several things. A great portion of hammer heads are made of square stock, so that it sits flat on the anvil and it's easier to find center when turned over. On round stock, it helps to mark both sides, and i've done it with blunt, pyramidal pointed stamps. It is supposed to be easier to see the pyramidal depression on hot, scaled stock than a conical depression. Another route is to lay out the hammer head length and center on the anvil face by drawing the dimensions with whiteout. I use Presto Brand correction pens. Again, if the stock is round in section, it can be placed in an appropriate bottom swage for eye punching. The bottom swage can be Presto marked for dimension. You may get a small, noticable 'frog eye' (side swelling) when fore punching, depending of the narrowness of the punch. If you do, you may use that as a guide when the work is turned over for back punching.

 

In attempting to correct the offset hole with heat, I would be tempted to use an RX capsue cross-sectioned punch with either a flat business end or a slightly concaved business end. This will bite into the excess material side of the hole and it should remove a burr. Sometimes you get a roughened eye interior, and that can be worked on the annealed stock with a rat tail file or a die grinder as Tim Miller suggested. Die grinders are dangerous and grabby, so use a light touch and move it always in the correct direction. After cleaning the hole, it may need to be re-drifted. Drifting will give the eye a final dimension.

 

Reference the side swelling at the eye, it can be hot-flatted while the drift is inserted, or it can be left as a swelling as in old Spanish hammers and top tools. Alternatively, it can be fullered and drawn edgewise into circular cheeks. The extra width gives more gripping surface to the wooden haft.

 

Finally, as you realize, it is easier to do it right than it is to rectify a mistake.

[Michael]

Finally, as you realize, it is easier to do it right than it is to rectify a mistake.

 

I'm curious as to how many TIMES I'm going to learn that lesson.  Seems to come up when I try something new. Thankfully I'm not trying to make a living at this, that would take all the fun out of it, for me.

 

Experience, what you get when you don't get what you want.