RyanMark Posted June 12, 2011 Share Posted June 12, 2011 Hello! I'd like to know what hammering strategies you guys think would be best, for hammering a plate of metal so that it's turned into a thinner sheet. The shape is a square, and the starting thickness is about 1/4". I'm familiar with "drawing" out bars (I've done very basic blacksmithing), so I am guessing that I should not hammer the middle of the plate until the rest is drawn out. Any thoughts on that, and whether I should work from one side/corner, or go around in a sort of circular manner and end up in the middle? And let's say, hypothetically, that I can't just buy sheetmetal. I need to make it. Thanks! Quote Link to comment Share on other sites More sharing options...
macbruce Posted June 12, 2011 Share Posted June 12, 2011 If the 1/4'' is larger than say 4'' x 4'' you're in for a real workout, even with a PH.........mb Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted June 12, 2011 Share Posted June 12, 2011 ive seen barstock forged into sheet Pieter Ross hammered out from a bar of 1/4x2 some sheet metal to make a lock ... used a cross pien and did most of the drawing using the pien and the base of the horn ...lotsa pounding and he used a caliper to ck the thickness... good luck Quote Link to comment Share on other sites More sharing options...
bigfootnampa Posted June 12, 2011 Share Posted June 12, 2011 You'll want to work the whole plate fairly evenly. If one side or corner gets much ahead you'll create stresses that will tend to make the sheet crack and/or warp. Slight stresses and warpage are unavoidable but if you let them get out of control you'll have serious problems. This is a challenging exercise... NOT a very efficient approach to production though. Assuming a fairly small plate (say 3"X4") I would likely work on two opposing sides and then the other two sides while trying to keep the center caught up with the rest. If you just want to get to 1/8" sheet or so, this is not easy but reasonably doable... if you are trying to get down to 1/16" or thinner it's going to be pretty difficult as the heat loss is SO SWIFT in those thinner dimensions. After a while, scale begins to thin the plate faster than your hammer does! Quote Link to comment Share on other sites More sharing options...
bigfootnampa Posted June 12, 2011 Share Posted June 12, 2011 I should mention that I have some experience at this sort of thing. I made a long thin trowel that my wife loves for her gardening. I took my time with it and forged it out to around 1/16" on the blade and only slightly thicker in the socket area (I kept the transition thick and strong though). She wants me to make many of these to sell... but they are too difficult to do swiftly... more of an artist's approach than that of the craftsman is required to get them this thin and light, yet strong. Only love can effectively motivate the effort required... money is NOT enough! Quote Link to comment Share on other sites More sharing options...
RyanMark Posted June 12, 2011 Author Share Posted June 12, 2011 If the 1/4'' is larger than say 4'' x 4'' you're in for a real workout, even with a PH.........mb They are going to vary from around 4x4" to maybe 10x10" and larger. And that was another question I had: Would a planishing hammer be the right tool for the job? I can only afford a HF model, and I think I know what everyone will say about those... But if it lasts for only a couple hundred hours, that would still be a start. And I should have mentioned that this is a copper alloy and I'll be working it cold with repeated annealing. Quote Link to comment Share on other sites More sharing options...
Old N Rusty Posted June 12, 2011 Share Posted June 12, 2011 I made a fireplace shovel mold from 1 piece of 1-1/2" mild steel plate 14" diameter a pipe blind. I laid out a shovel and started cutting it from the thick steel at the top end it was about 3-1/2" and nearly a verticle cut and the sides are 30 deg. tapering and flareing slightly, to the the flat end about 5" wide. it was many lunch 1/2 hours cutting and grinding but i was satisfied with the mold shape. This i got out of the plant and another pipe blind. The same thickness but bigger. At my shop I welded the two together making a swage mold. a piece of 4" x 3/16" mild steel flat bar six ? inches long will make a fireplace shovel.I forge the plate with a thick spine and drawn down to less than 1/8" on the raised sides, and the back is thicker. Flattening each heat there is plenty of thickness to move with hammer blows from the center out. and a thin taper forms to the mouth of the shovel always leave the edges thick when drawing out the plate and work it on the anvil on both sides then using an annealed cross peen as a struck tool i formed the shovel in the mold. the next one i want to leave enough on the top to make a socket for the handle. Quote Link to comment Share on other sites More sharing options...
macbruce Posted June 12, 2011 Share Posted June 12, 2011 They are going to vary from around 4x4" to maybe 10x10" and larger. And that was another question I had: Would a planishing hammer be the right tool for the job? I can only afford a HF model, and I think I know what everyone will say about those... But if it lasts for only a couple hundred hours, that would still be a start. And I should have mentioned that this is a copper alloy and I'll be working it cold with repeated annealing. Yes you should have..........Not really.......................You're still in for some elbow grease, not near as bad though. I'd work it cold, then anneal over and over........All I know about the hammer to be used is it can't be too flat or too aggressive...somewhere in between. What's an HF?? Quote Link to comment Share on other sites More sharing options...
pkrankow Posted June 12, 2011 Share Posted June 12, 2011 What's an HF?? A brand of cheap import. The HF planishing hammer is a waste of your time. Copper or steel the principle is the same. Hot copper moves like soft butter, it is pretty darn cool. The problem is "hot" is dull red just like annealing, so it is a hard temperature to hit for a big piece. You can then work it until it is cold and needs to be annealed. Annealing doesn't care if it is quenched in water or air with "normal" metals. (Steel is not a "normal" metal) I tried spreading a piece that was about 2x2 to 3x4 in steel, and until I burned it away starting from the center was the ticket. I got the edge too hot and thin and suddenly the metal vanished! Best of luck. Phil Quote Link to comment Share on other sites More sharing options...
Ed Steinkirchner Posted June 13, 2011 Share Posted June 13, 2011 my method has always been to use the cross peen all one way, then turn 90 degrees and repeat for square, or then turn 45 then 90 to that for a circle. Does that make sense? Anyway, a hammer with a cross or angle peen with a 1/2 or 5/8" diameter on the peen, is what has worked for me. What are you planning to make with the sheet? Quote Link to comment Share on other sites More sharing options...
RyanMark Posted June 13, 2011 Author Share Posted June 13, 2011 . Quote Link to comment Share on other sites More sharing options...
pkrankow Posted June 13, 2011 Share Posted June 13, 2011 So should I use the peen side to distort the plate, then flip it over and even it out with the flat hammer face, like my crude drawing? Working a bigger area than illustrated would be good, but you got the idea. Phil Quote Link to comment Share on other sites More sharing options...
Ric Furrer Posted June 13, 2011 Share Posted June 13, 2011 Ryan, I assume this is mokume or similar. The simplest would be a large rolling mill. failing that have a look on youtube for the Copper vessel makers of Mexico or related videos. As a general rule you are looking for spread in two directions not four which means a fuller...a rolling mill being a continuous fuller. A small power hammer with drawing dies would be useful..25 little giant or similar. I would think with some looking you could attend a blacksmith gathering close to you and have them help you. Ric Quote Link to comment Share on other sites More sharing options...
bigfootnampa Posted June 13, 2011 Share Posted June 13, 2011 Copper is really much different... EASIER. Because you can work it cold. It is also softer (WAY) and withstands the stresses of slightly uneven stretching better. Copper mixed with iron is not so good because they tend to separate due to different reactions to the forging forces. I've thinned copper down pretty far, mostly in jewelry sizes though. Quote Link to comment Share on other sites More sharing options...
RyanMark Posted June 13, 2011 Author Share Posted June 13, 2011 . Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 13, 2011 Share Posted June 13, 2011 What "copper alloy"? Pure copper is a joy to work, many of the alloys are almost impossible to hammer out like you want. The Devil is in the Details! And as Ric mentioned this is generally done with a rolling mill. they make some fairly small ones for jewelry making that might handle this (I'd roll one way, reheat and roll from the 90 degree side) Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted June 13, 2011 Share Posted June 13, 2011 "copper alloy"...???? Bronze is a copper alloy and so is brass, so which one is it? The are hundreds of different alloys on the market all have different forging properties to them. Nickle copper alloys are another category along with gold and silver alloys, boy is your request rather vague with your comment on "copper alloy". I make up a Japanese alloy of copper and silver and it is rather springy to forge in even small pieces but has a nice color for jewelry. There is silicon bronze in great numbers for different service requirements but all are highly corrosion resistant and many here on the forums forge with them so if you look around you will find information on that. There are the zinc based brasses that have been use for centuries to cast every thing from cannons to shoe buckles and plumbing valves and can be forges. Traditional tin based bronze is an ancient metal that changed life for mankind with it's hardness for weapons and tools. It can be forged too but is usually cast and then forged to work harden the cutting edge to allow for sharpening. A truly life changing metal. So which copper alloy do you have? ;) Quote Link to comment Share on other sites More sharing options...
RyanMark Posted June 13, 2011 Author Share Posted June 13, 2011 . Quote Link to comment Share on other sites More sharing options...
macbruce Posted June 13, 2011 Share Posted June 13, 2011 '' It looks like a power hammer is going to be an inevitable investment'' That's the spirit!..............:lol: Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 14, 2011 Share Posted June 14, 2011 Several times I have seen videos of gong and cymbal makers in 3rd world countries doing this sort of thing---might be a good idea to see how they are working it! (Indonesia and Tunisia come to mind...) Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted June 14, 2011 Share Posted June 14, 2011 I know that this is of little relevance, but for those of you that are drawing out steel.I find that when I am drawing clips on horse shoes, at black heat rapid solid blows actually adds Enugu energy to leave the namer mark at dull read heat. You can draw a clip in one heat if you keep up the rhythm. Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted June 14, 2011 Share Posted June 14, 2011 from cast disk to finished cymbal Quote Link to comment Share on other sites More sharing options...
evfreek Posted June 15, 2011 Share Posted June 15, 2011 For reasons of safety, it is important to stay away from thin spots in the metal. Almost no matter how hot the metal is, a hammer strike will rebound sharply from a thin area. One can think of it as there is almost nothing between the hammer and the anvil. Another way to think about it is that the only way the metal can get out of the way is to be extruded in a thin layer. Yes, for those of you who are wondering, I did learn from the accident :( Quote Link to comment Share on other sites More sharing options...
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