I have a new Contenti economy mill and am starting to roll bigger pieces of metal, such as bracelet blanks. I’m using metal texture plates and am not getting an adequate impression……wondering if my copper/brass is not adequately annealed? I have a small butane torch and wonder if perhaps it’s not powerful enough to anneal a 2”x6” piece of metal? I have the mill tightened down as tight as i can turn it……and dont want to strip my gears!
Charles Lewton-Brain has a lot of advice about how to anneal copper. Look him up in the archives. My guess is that your torch isn’t big enough. Annealing copper takes a lot of heat, especially the size that you are working with.
In order to be properly annealed, copper must be heated to a red color…the exact color of red, I’m not sure of, but I’m sure that if you look at some internet references, you will find it. If your copper doesn’t glow red, you haven’t annealed to a high enough temp… -royjohn
You heat until the shadows disappear. Another tell is when the flame turns orange. Copper takes a lot of heat.
Ooh yikes, yeah- I work with butane torches and even my biggest one would be hard pressed to properly anneal a piece that big especially if it’s any thicker than 22g. In situations where I need to anneal a larger piece without cutting it down, I’ve actually used a burner on my gas stove. It works great! Plus the look on my housemate’s face was PRICELESS.
I had to anneal a 2X6 22 gauge piece of sheet copper. I tried with my Blaze GT8000, which is about the biggest butane torch you can buy. I was never able to get the shadows to disappear. I could get it fairly red, but had to go one small area at a time. My guess is that you need a bigger torch that will deliver more heat. Torches can be expensive, but they are a lifetime investment. A lot of people use the Little Torch. I have one, but I would not use it to anneal a large piece of copper. I also have an EZ Torch. They are fairly inexpensive and you can use a 1 lb. camp stove cylinder with it. The flame is a bit unpredictable and bushy. My go to torch is a Meco, also on 1 lb. camp stove cylinders and an O2 concentrator. There is a lot of information about torch systems in the archives. Good luck…Rob
Thank you to everyone who has offered their thoughts. I had a hunch that my torch was inadequate, so I appreciate knowing that! I will research the archives. I have been wanting to learn enameling, so I had a hunch that a new torch was in my future for that.
Thank you also for the information on the rolling mill capacity- I think my little mill ( which I bought for milling filligree) is perhaps not suited for what I’m trying to do. Now I know!
Ooh, if you’re going to try enameling, a Hot Head torch and canister of MAPP gas or propane is perfect. I recently got one and it’s a monster compared to the butane models. It’ll easily handle big pieces of copper. Just make sure you’ve got a fireproof surface big enough- I got a full-sheet steel baking pan from a restaurant supplier to put under my tripods and trivets.
I can easily anneal 6"×6" pieces of 20ga copper with the Harbor Freight propane torch (for about $20). For 12"×12" or larger, I use a weed-burning torch.
I just put the sheet of copper on my gas kitchen stove and it heats it easy. For long 6” x24” —22ga I just pull it slowly along letting it get good and red as I go.
What do you use to solder with?
When you clamp the material in the mill, are you turning the rollers down to tight with all pieces in place, then backing the rollers out to remove the pieces (count the turns), then turning them so they are a little tighter than when the material was in the rollers? It’s important to tighten more than the thickness of the sandwich. That extra tightening is the depth of the impression you will get. The rollers act as a force amplifier (the longer the handle on the mill, the more force applied when rolling).
I turn my HF torch to an appropriate level. I do a lot of annealing, but not so much soldering. I have a Little Torch, and would use that if I needed to do more soldering.
Yes, I’ve been doing that. My mill doesn’t have measurement marks on top of the horizontal gears so it’s hard to know how much to tighten down after I back the sandwich out. I think I’ll try making a template with marks and see if that will help me a bit. It feels like finding that “sweet spot” is hard- tight enough to make a good impression but not so tight that the metal shape is altered.
Use a sharpie to mark the gears where they mesh once you find your “sweet spot”. Use numbers for different sandwich combinations. You can also use feeler gauges to replicate a size.
Just got a nice impression on some 18 g. copper so I marked the top of the gears and also used the feeler guage to make a note of which measurement is a good one. I did not think of using the feeler guage to do that so thank you for offering the idea!
Hope it works…Rob
There are butane torches that can anneal a piece of copper that size, I use this Iwatani torch that has a big bushy flame (that top attaches right to the top of the butane can) I’ve also used a MAP plumber’s torch, both of which I got at Home Depot. I got a flexible handpiece for the MAP canister for torch-fired enameling and it works well. No good for fine work but good for annealing and enameling.
I love this helpful thread and since we’re talking larger pieces, say 6” X 2” for a cuff, I make a lot of cuffs, many I do a lot of stamping on cuffs or run it through my mill, but I have an awful time annealing silver, say14 or 16 ga. Anyone here that can offer help? I have even tried annealing a piece 2-3 times trying to make it as malleable as possible. Thanks in advance.
are you quenching the silver soon after red glow is gone?
if you wait too long you could be hardening your silver…?
try searching forum for quenching, etc…