How to forge a large ring?

[Kristopher Skelton]

If you don't have a floor mandrel or a swedge block, how would you make a ring 7" in diameter? I tried making a circle of 1/2" round stubs welded to a plate, but it was a PITA to get the ring finished. Plus it wastes the plate and is only good for the one size.

Thanks all!!

[Ralph]

Have not needed a ring that big, but it seems if you had need of them, why not make a plate steel 'pegboard' and metal dowels to use as a jig. Or mebbe do as I would most likely do just eyeball it.

[Ten Hammers]

Ok here goes. You need to answer a couple for me. This ring is made from what stock ? Is this really a spec deal or can it be close? Inside or outside diameter ? Start with 21" + 4 times the stock thickness. You plan to forge weld the joint or mig/gas weld it ? Depending on the stock, the ring can be started ( and made actually ) COLD in the jaws of the vise. Then, get the joint lined up and weld ( need to know type of weld here).
For an electric weld, just line up and get with it ( fill the tight gap/crack). True up the ring on the horn ( striking the outside ) on the ledge (cutting ) striking inside and or hold over the tail of the anvil (striking outside). Be patient and tap. This is where 15-20 years of collecting stuff comes in handy. Pipe will work to true up rings. A collection of hammers will be helpful as well. A strike from a cross pien in one place vs a strike from a straight pien will change things. Also, a round faced hammer vs a square faced hammer ( different radius on hammer faces). You will notice I am still working this ring cold, holding it in bare hand (after the weld cools). Juniors pipe saddle tooling ( for the hardy hole) works well for this (striking inside). If you need a bunch of these, you can duplicate them. Let me know whats up with these questions and I'll try and help. If this is a ring for a bottle to set in ( like for a mig stand or an acetelyne cart ) and this is bar stock you're using thats fine. If you need to fit the ring to a specific piece I might make the ring in the vise ( cold, bending with hands ) and true it up on the anvil before welding. Get the ring as close as you can. Be patient. If the ring is too tight, you can add some. If too big, just remove some. 3/16 - 1/4 x 1 or 1 1/2 bar can be done in this manner handily ( this will depend of course on your vise ). If you want a nice clean joint you can just heat with the torch ( joint only ) and forge the weld ( stick or mig weld ). This will stretch it some. You can just grind it if you wish. You can also heat the ring in the forge and hot file the joint. I FOR SURE would take notes and make a sample to hang on the rack. Wrap a piece of duct tape around the sample and write the starting length with a Sharpie.

[ThomasPowers]

Look up what a bending fork will do. Check the size of every piece of curved metal you have---I collect the oddball items just to have various radii to hand, (old fire extinguishers came in an amazing number of sizes...)

Thomas

[Ed Thomas]

In my opinion, you should always welcome a chance to practice or learn a fundamental forging skill. If you had time to ask how to do this, then it must not be a rush job. Let's assume you are using 1/4" x 1" flat bar, you want the circle to be 7" on the INSIDE diameter, and you are bending the flat part. The basic steps are:

1) Figure out the length of material you need for a 7" ring. The formula for a circle is pi * diameter (3.1416 * 7). This will be the circle to the MIDDLE of the material, so you need to add pi * 1/2 the thickness of the material (3.1416 * 0.125) which means you need an additional 22" + 0.4". If that sounds like too much trouble, just multiply your diameter by 3.2 and you will be close. So we have 7 * 3.2 = 22.4". (If the material is quite thick this shortcut won't work, though!)

2) Take a compass and draw a 7" circle on a flat piece of steel using soapstone or chalk. This is the inside diameter.

3) Heat one end of the stock and upset it. This length is great for just dropping/throwing at a piece of steel on the floor to do the upsetting. Scarf that end for a forge-weld.

4) Heat the other end and upset the same way. Scarf it upside down from the first end.

5) Bend the bar using bending forks until you have a ring. This way is often easier to me than over the horn because you can see the curve and avoid flat spots. Continue bending until the ends of the scarf overlap.

6) Forge-weld the scarfed ends over the horn of the anvil. Weld thoroughly, but don't let it get too thin. Remember that the horn will fuller the metal quite rapidly and you will need some thickness for adjusting the ring.

7) Get it roughly round, and lay it over the soapstone ring you drew. Note how much it must "grow" and work the thick part of the weld down at a very high heat until the ring is right. Work to get the ring very round to match the picture by using forks or the horn.

8 ) Take pictures and post them here.

If this sounds hard, do it anyway. :mrgreen: After one or two of them, it becomes quite routine and not difficult at all. Really.

One other comment: The area of the forge-weld will be VERY forged. If you don't re-forge the steel before making the ring, then the weld area will really stand out -- you'll have a milled look with hammer marks from shaping growing out of a heavily forged welded area. Make sure you do the reforging BEFORE you measure the length you need for the ring, because the reforging will probably make it longer.

[Kristopher Skelton]

Thanks guys! The gist of the problem was that the ring I needed to make is significantly larger than my cone mandrel (4-1/2" cone).

10hammers: not a production piece and as I tell people "if you want it to look like a machine made it, find a machine" I made the first one out of 1/2" round and figured if I was gonna make any more I'm gonna need an easier way to do it. I'll work 1/4" cold, but the 1/2" isn't agreeable enough. I went with "forge" welding (actually oxy-acet for the heating and then hammered the scarfed ends together).

Ed (and Thomas): I basically used your method (work it around a drawn circle with hammers and bending forks and get it close to a drawn circle) and it sounds like good, ol' fashioned hard work may be the best way to go until there's a forming tool that I can justify purchasing I hope it didn't sound like I didn't want to do the work (because I DID do the work) but the hardest way isn't always the best way, and is usually the least efficient sometimes you jsut do what you have to because you can't justify buying a tool or making a jig for a one-off.

The ring was for a fireplace screen that I finished monday night. I'll post pics on my website tonight when I have a fire going behind it (and I'll take a few of the ring, close up). I'll add random sized rings to my "do it while the forge is going anyway" projects along with twists and hooks.


thanks again!!

[6013]

Find something the size you want and form it hot. It will stay close to the size of the forming tool.

[Woody]

I have a 11 1/2" dia disk brake roter that has a raised bolt surface in the center that is exactly 7 inches in dia. Go to the junk yard or brake shop, find the appropriate roter. Take it home, heat your steel and bend it around the top portion.

Woody

[Ralph]

Find something the size you want and form it hot. It will stay close to the size of the forming tool.

Actually if you go slightly undersized and form the ring it should spring back to almost 7 inches.

Ralph

[Ten Hammers]

If you must make a ring, just get a traveller wheel and measure a piece like Woody described. Make your marks. Measure and mark your stock. Mark your stock with a chisel for correct length ( no additional since you've used the traveller and you have no dish to figure)Scarf, forge the ring hot, line the scarfs up, weld and true on the horn. My 1st post was simply the FASTEST way to do it. Length = diameter x 3 + 4 times the thickness and this works very well. You can true up on a traditional tire roller ( used extensively before the turn of the last century ) and you have the deal done. To stretch, do as mentioned. To shrink, use a tire shrinker. This AIN'T complicated, it is exteremely simple. Practicing traditional skills is of course something that needs to be done. I make my living at this. I ain't the brightest bulb in the box but I do shine. :)

[Ralph]

You can true up on a traditional tire roller ( used extensively before the turn of the last century )

Speaking of which I believe Woody had a nice BP about building a tire roller.

Ralph

[Ten Hammers]

Kristopher, I 'm really sorry if I came across as a smart elic or was condescending in my last post. The fact that I'm full time now does not mean I know any more ( mebbe less:p) than anyone else. I saw no mention of " traditional " in your question. When I make something new, I normally keep a pattern ( hence my question about you might want to make more). Consequently, my shop is maxed out ( and I mean cubed). Material handling, space and time management are the most important things in running my business. Where do you live ? I'd be happy to have you in the shop anytime. Bloomfield, Iowa here.

[Kristopher Skelton]

No offense taken I didn't mention traditional because I didn't want to close any avenue (for all I know someone makes their rings with tinfoil and a toothbrush ) Although, I suppose given my limitation of space and funds I end up doing things the "traditional" way. I appreciate the offer, and if I'm ever on the "other" coast I'll let you know and we can get together. And I extend the same offer, just drop a line.

For the record, rings really ain't that hard but knowing several ways to make something is good in my book :)

[Kristopher Skelton]

That's what the ring was for Overall dimension is about 35x33 at the top of the arch.
More pics at http://www.alchemyforge.net/fireplace-screen.html


Edit: photo added

[dan@modernblacksmith]

gone

[Kristopher Skelton]

I tried that first, but I couldn't get the ring small enough to fit the screen So I had to make one the hard way ;)

[irnsrgn]

[dan@modernblacksmith]

gone

[HWooldridge]

For a one-off job at the forge, I basically follow Ed's process. I draw my sketch on the work table, cut the material at 3.2 times desired diameter, heat one end and curve to match the drawing, then reverse and repeat. At this point, I have a long "C" with a flat back. Depending on material and circle size, I either finish cold or hot - the former preferred for ease of handling and consistent movement. This is for a butt weld ring - a forge weld needs extra added for the scarf.

No hard spots in the bar and a consistent temp will make a smooth bend - one of the reasons a long orange heat is often better for bending than an isolated hot spot.

Ed will throw darts at my portrait for saying this but another good way of making rings is to cut them from the appropriate size pipe. Of course, this is very common in production shops but a good smith can add sufficient texture to make them look hand made. :wink: