MarkC Posted September 4, 2009 Share Posted September 4, 2009 hello all, I've got to punch/drift and rivet through 1 1/2" square, which will be a railing newel post. Anyone have any pointers on this? I haven't punched anything this thick before and don't know what to expect. piece of cake? mark Quote Link to comment Share on other sites More sharing options...
David Einhorn Posted September 4, 2009 Share Posted September 4, 2009 The level of difficulty will likely depend on whether you are using a power hammer or have a striker with a sledge hammer. Plus the thicker the bar you are punching though, the faster your chisels, punches and drifts are going to potentially heat up and deform. My suggestion is to work fast under a powerhammer and quench your tools often. :D Quote Link to comment Share on other sites More sharing options...
double_edge2 Posted September 4, 2009 Share Posted September 4, 2009 (edited) got a test peice. i ...... might pre drill, then drift. or power hammer. i pre drill and then by hand hammer. 45mm Edited September 4, 2009 by double_edge2 Quote Link to comment Share on other sites More sharing options...
petere76 Posted September 4, 2009 Share Posted September 4, 2009 marc, Because of the time the tooling will be in contact with hot metal, consider A33 for the tooling. The A33 is air hardend and seems to hold up longer when used under these conditions. In regards lay out, I usually pre drill large pieces of stock to get a good course line for the tooling. Off center alignment is very time consuming and has led me on more than one occasion to re-do that particular piece. Peter Quote Link to comment Share on other sites More sharing options...
Ed Thomas Posted September 4, 2009 Share Posted September 4, 2009 Actually, yes, it is a piece of cake. In many cases, within reason, the larger the piece, the more forgiving it is. Small adjustments on a small piece have a MUCH bigger effect than small adjustments on a large piece. Because your bar is larger, your tooling can be also, and you might find that it is much easier to center, straighten, correct, etc., than on smaller stock. Tooling is beefier, so will resist deformation longer. If you are used to using spring steel, continue using spring steel... just remove quickly and quench often. Use coal dust lubricant. You didn't say whether you were drifting square, diamond, or round. Regardless, figure the perimeter of your hole, and make a slot punch with slightly less than that perimeter. For instance, if your hole is 1" round, then you want a slot punch of no more than 1.5"... maybe 1.4" would be better. After upsetting the hole to round, drift to suit. As always, make sure your heat is even and thorough to aid in keeping the punching straight. Usually I drift from the opposite side I punched, unless I want to emphasize the distortion on one side. You don't need to use a power hammer for that small a bar. In any event, try a test piece to make sure it is how you want. You will probably be surprised at how easy it is to do. Quote Link to comment Share on other sites More sharing options...
Fe-Wood Posted September 4, 2009 Share Posted September 4, 2009 I have used this method with outstanding results. Slitting is SOOO much easier than slot punching. Consider putting your finger through a watermelon, then putting a knife through the watermelon. Note how easy the knife goes through. Also, the pointed slitter makes alignment a breaze. Good luck and definatly do a test run on scrap.BP1064 Slitting and Drifting | Blueprints 1000 Quote Link to comment Share on other sites More sharing options...
mcraigl Posted September 4, 2009 Share Posted September 4, 2009 Marc, Lots of decent suggestions so far. You didn't tell us what your experience level is, or what tools you have available to you, etc. Do you have a hydraulic press or Power hammer? Etc. Purely by hand. I suggest that once you figure out what size slitter punch, that you make two identical ones. I'd go for H-13, or some other hot work steel then rotate. A-33 may be a good option, but not because it's "air hardening". It's NOT air hardening. It's water hardening, non-tempering steel. The nice thing about it, is that you can dunk it in cool water no matter what temp it is, and you don't have to temper it afterwards before going back to work with it. H-13 and no quench and rotate two identical punches, or A-33, and quench after every piece. Good luck and show us pix when you're done. Quote Link to comment Share on other sites More sharing options...
MarkC Posted September 6, 2009 Author Share Posted September 6, 2009 (edited) oh man, great advice from all as usual. I think I'll predrill and then drift, to keep the hole as true as possible, I was leaning that way originally. Will also try Hofi's slit method. We'll see how it goes on the scrap pieces. I'm not going to get to this part of the project for another week or two, i just like to study up well in advance, so work keeps moving smoothly. as for experience, i've got enough to know when to ask for advice haha Edited September 6, 2009 by MarkC Quote Link to comment Share on other sites More sharing options...
Ed Thomas Posted September 6, 2009 Share Posted September 6, 2009 I usually try to avoid responding if someone differs with my advice since the reader can make up his/her mind by attempting the different methods and living with the results. However, I do want to make two points: 1) The analogy of putting a knife into a watermelon vs putting your fingers into a watermelon makes no sense to me. I cannot figure out how that is related to the choice of hammering a slitter or a slotter into a piece of steel. Maybe if you hammer a knife and then your fingers into the watermelon??? There are good reasons for slot punching: It is much more forgiving to use and the ends of the slotter are less likely to leave a scar, if that matters in the piece. But in my experience it is no more or less difficult to drive a slotter into a piece of hot steel than a slitter, as long as it is designed for the task. A slotter is easier to keep centered and doesn't wander as much if ground slightly off as a slitter will do. Which method a person uses seems to me to represent what they were taught and are most comfortable with, as both tool choices work just fine. 2) If you look at the blueprint example, the choice to drift that particular piece in that particular manner thinned the walls of the through-hole considerably more than I usually want. In most cases, if it is possible to do so, I prefer to slot punch (which leaves rounded ends of the slot), upset the end to open the hole (which should come out close to the final size without tool scars) and then drift to the final shape. The walls around the hole will be thicker and flow more naturally. This works well for me. You can use whatever works for you. Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted September 7, 2009 Share Posted September 7, 2009 THE SLITTERS VS THE SLOTTERS! O.K well, I'm a slot kinda guy. Seen people do well both ways, so I guess there is no "right" way. Ed describes it just like I would do and he even has all the same reasons! Go figure! Drilling and then trying to stretch the hole out does not work as well in practice as it sounds. Better to drill two holes and then slot out the "tween". Quote Link to comment Share on other sites More sharing options...
MarkC Posted September 7, 2009 Author Share Posted September 7, 2009 ok, at this time, I'm going to mention that this is only for a round rivet hole, around 3/8" (I havent settled on a rivet size yet). I guess that's going to be a pretty small slot punch, since i'm drifting out to only 3/8" round... ? this is to rivet a 1 1/4" x 3/8" flat subrail to a 1 1/2" square newel. by the way, asking questions on this forum always feels like cheating!!! I feel like I'm suppossed to be figuring this stuff out myself lol. but the hints, tips, and hearing how other people do it is always incredibly helpful. Quote Link to comment Share on other sites More sharing options...
Ed Thomas Posted September 7, 2009 Share Posted September 7, 2009 Marc, Every one of us learned by watching, reading, questioning, and being taught by others in some fashion or another. You DO have to go try out what someone says to incorporate it into your skill set, but there is nothing new in forging techniques. It has all been done before; we just use the techniques in fresh ways sometimes. I like to figure some things out myself, but reinventing the wheel just takes time away from the more productive things. Is the flat bar going to be vertical or horizontal? If vertical, then you probably don't want a round hole anyway. You would be better off forging a flat tenon and punching a rectangular slot (mortise and tenon). That way the bar will be much more secure, can't rotate, and will provide much more rigidity to the frame.Mortise and tenon - Wikipedia, the free encyclopedia If it is horizontal, then consider a smaller tenon anyway, and forging a dado (blind, preferably) to hold the bar more securely. http://en.wikipedia.org/wiki/Dado_(joinery) Forging a dado takes a little thought, but is not hard. You just have to remember that you are displacing material rather than removing it, so as you hammer into the bar, it stretched lengthwise. So you can't just hammer a 3/8" set or bar into the material and expect a 3/8" slot because as soon as you square it up, you will find that it will be a wider slot, proportional to the depth you set. It is a "constant volume" forging exercise and very satisfying to do. Take a practice bar and play with it. Joinery is some of the best part of forging. Quote Link to comment Share on other sites More sharing options...
Alwin Posted September 7, 2009 Share Posted September 7, 2009 If you go with a round hole, you can key it to prevent the tenoned bar from rotating. By keying, I mean take a chisel and drive it into the edges of the round hole, mortice, on the side you will be bradding over the tenon. When you upset the tenon it will be pushed into the chiseled slots and lock it in. Quote Link to comment Share on other sites More sharing options...
MarkC Posted September 7, 2009 Author Share Posted September 7, 2009 I would post a photo of the drawing for clarification, but I am not on my home PC at the moment, so i'll do my best. this is for a stair railing, so the subrail will be runningg into the newel at an angle. I had initially planned to use a mortise and tenon there, but I came to think that riveting would be easier, in that I will bend the last 2 inches of the flat bar subrail to run paralell the newel, creating a riveting flange. I think it will look nice, and I can more easily control the subrail angle that way, than if I were trying to angle a mortise and tenon joint. I also thought: make the mortise and tenon at 90 degrees, then simply heat and bent the subrail to the proper angle... but that will get messy as the flat will be firmly shouldered against the newel... a foolish idea. as for the flat sub rails rotating, they will be held from rotating by the balusters, which will be joined to them. Quote Link to comment Share on other sites More sharing options...
Ed Thomas Posted September 7, 2009 Share Posted September 7, 2009 Unless you are looking for the unique (and appealing) distortion caused by punching, I think I'd probably back off and recommend drilling. The holes you are making for rivets just aren't big enough to make much of a difference in the appearance, and lining things up will be much easier by drilling. You can bevel the top hole in the railing and pein the rivet to fit in the hollow so it is flush with the railing, pretty much making it disappear. The rivet head can be supported from underneath. Yes, your design idea can be very attractive and sounds good to me. I had a much different mental picture of what you were asking. Apologies. Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 8, 2009 Share Posted September 8, 2009 I had the impression you were going to drift for a larger tennon too. And as Ted says what you plan on will be too small to make the pleasant swelling a drifted hole causes. So, this brings up a question. Is there a % of the parent stock a drifted hole needs to be to give the most appealing bulge? Some are barely noticable and others are so pronounced as to have enough WOW factor it can take away from the overall piece. For myself I find about 50% makes a nice swelling around the drifted hole. To put numbers to it, I like the looks of a 1/2" drifted hole through 1" stock. What do you like? Frosty Quote Link to comment Share on other sites More sharing options...
Mark Emig Posted September 8, 2009 Share Posted September 8, 2009 Just a quick note on H-13. According to Carpenter tool steel informational charts you CAN quench H-13 during use. I alway thought you couldn't. I finally figured out that if I read the spec sheets I might learn to use the proper steel the right way. Mark Quote Link to comment Share on other sites More sharing options...
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