Hi guys,

 

I am designing a memorial sculpture to honor a deceased Vietnam vet.  It will be about four feet high and maybe 1-1/2 feet wide.  It will be an impressionistic flame.  Since it will be mounted outside, I am considering using 3/4" hexagonal bronze stock.

 

I have never forged bronze before.  Are there any tips or techniques that are different than steel?  Temperatures, finishes, etc.  Any other material I could use for outside?

 

Also, where is a good supplier?  I have found only one in Denver, CO and NY that handle small orders.

 

Thanks.

Some bronze can't be forged, but if you do get a forgable variety the rule of thumb is if you can see it glowing it's too hot.  Generally when I'm forging, all be it smaller than what you are going to tackle, the bronze will begin to darken then faintly begin to glow.  That's when you do your work.  If it's too hot it will break apart.  Not fun. :o

Watch your heat. If you get it into an orange, take it out of the fire and let it cool back to a red. It might be ok then.  Dorothy Steigler did a bronze forging workshop near here a couple of months ago. She came up with the term burn it to learn it. The bronze we used was a silicon bronze and had a narrow working range. It heats back up fast though so don't get distracted while heating it, otherwise you're liable to burn it. I forget the alloy other then a silicon bronze 655 maybe? There is also naval bronze is suppose to forge good also.

 

Other people will suggest working cold. Heat, anneal, work till it work hardens, reheat and repeat.

 

So there are a couple options. Good luck and keep us posted.

Greetings Dave,

 

JM and Rashelle have covered most of the cautions on material and forging..  My only suggestion is to forge in a very dark room so you can see the colors of the material better... I has worked well for me in the past...  Good luck

 

Forge on and make beautiful things

Jim

I don't believe there are many metal suppliers that handle bronze of your type.  Atlas Metals in Denver is the only one I know of.  Since you are on the East Coast the NY one may be the best.   The warnings above are correct and I found that by working some small pieces I found the heat range to work the bronze, and I did burn some parts up.   You could make it in mild steel and patina it.  There are many patina's that might work well for you.  Good luck and send pictures of your work.   

Yeah, 655 or silicon bronze and naval brass are readily forgable with a working range between 850 and 1150 degrees F. I recommend using a laser pointer pyrometer to determine the color range using those temps as upper and lower limits. Trying to describe the color accurately is impossible, because of lighting variations. It will be soft and move far with each blow but not stay at working temp long. 

 

As noted, too hot and it crumbles, too cold (and worked too much) and it cracks.

3/4'' hex what?? Why hex? I hope you don't plan on forging a taper with it, that might prove to be problematic since you can't forge a common hex with a hammer and anvil or even a power hammer without special tooling......

You can do hex even tapers with hammer and anvil. It's (for me at least) just not as natural as square. For myself making myself forge a hex taper I have to think through it. establish the hex then keep it. So either turn in thirds or keep turning and turn in 6ths. Rather then turning in quarters. Besides it's a viable starting point if 3/4 hex is his starting material he doesn't have to keep it hex.

 

Finding a shadowy spot in the forge helps to use to judge the initial color and feeling for it work hardening as it cools. Sacrifice a piece and find your high and low working temps. It's fun to work with.

I may be wrong, but doesn't Brian Brazeal forge hex tapers all the time?

Copper based alloys transmit HEAT; do not expect to be able to hold one end in your hand even with a glove and work on the other end!!!

 

I'll also dogpile on Silicon bronze as a good alloy to work.

Thanks all.  You have confirmed what I have heard throught he grapevine. 

 

I'm using the hex as a texture and shape starter.  Parts of the rod will be twisted and parts will be flattened or flared.  The taper will go from hex to round at the pointed ends.  I'll post some pics when I get started.  I have to have the sketch approved before I can start and I have to find the stock.

 

Thanks again.

May want to start with square, or round instead of hex. Check prices first.

Jeremy,

 

Can't speak for Brian Brazeal but I can say that his video's on forging round tapers go square to octogon, then planishing to round.

 

Six sided doesn't sound too easy to eyeball but I don't doubt it's possible.

Forging to hex (instead of square) is used in this video (making a hammer-eye drift): 

Hex looks awesome twisted. 

Nice video. But the question for a taper shouldn't be why to taper hex cross section to round instead of square cross section to round, but why hex instead of octagon?

The only reason I can see is to improve your skills at forging a hex, which is certainly a good reason.

I don't believe I would do my tapers square-hex-round as a normal course of action.square -octogan-round works for me.

Intuitively to me, seems there is more control of the taper via octogan, but it could be just habit.

When I am forging bronze I judge the time in the fire by turns of the blower crank rather than by color of the metal.  Counting seconds also works.  For example, bringing a cold 1/4" round bronze brazing rod to working temperature in my forge takes about 10-12 blower turns.  Only about 3 to return it to working temperature while working it.

 

I can carry on a conversation while forging steel.  I cannot while forging bronze, it takes too close attention.  Any distraction will make it likely that you will burn the work.  Small pieces (1/4" and smaller) are much easier to burn/melt.

 

BTW, the folk at Atlas Metals in Denver are very nice to deal with.  Ask if they have any drops from their fabricating operation. 

Definitely price hex vs. round. 655 everdur is what you want. I'm saving money to place an order too... Have many items I want to make in Bronze...

How did this project go?

 

If not yet then I suggest using a gas forge set at the forging temp...saves much in mistakes till you get a feel for the material. If not then darken the shop and go to red. I suggest having a test bar every time you go to work and play with it first ..each day you forge...to get a feel.

I like 655 bronze....forges well, welds well with TIG and has good color.

 

Ric

I recently worked with some Silicon bronze . I forged Habaki for big wide Wakizashi . Pretty much treated it like copper . Anneal often  quench or let cool to room temp and hammer away . I normally don't work with bronze, thought I would give it a try. I used a 3/4 " rod . I still need to solder it together . It was not bad to work  at all . I believe one of the members here suggested that I use S. Bronze . I made 2- 90 degree bends without cracking .......   James

Why did you work it only warm? Were you not aware that you can forge it hot or were you playing safe? I made some silver spoons once, the first pair I did like you, by annealing and then cold working. The second pair the blacksmith in me took over and I did them hot in quarter the time…bit hairy with a few pounds worth of sterling silver at risk!

Copper, bronze, brass and silver work like butter / plasticine at the correct temperature. You are really losing a huge amount of metal-moving-per-heat potential by just annealing and letting it cool…must have taken you ages.

Alan

Edited June 28, 201510 yr by Alan Evans
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and you wonder why you got banned today?

 

 

 

 

 

 

Edited June 29, 201510 yr by Steve Sells

I love hot forging fine silver.  If you have a brass/bronze alloy that is hot forgeable  do try it; but most are not unfortunately.

Why did you work it only warm? Were you not aware that you can forge it hot or were you playing safe? I made some silver spoons once, the first pair I did like you, by annealing and then cold working. The second pair the blacksmith in me took over and I did them hot in quarter the time…bit hairy with a few pounds worth of sterling silver at risk!

Copper, bronze, brass and silver work like butter / plasticine at the correct temperature. You are really losing a huge amount of metal-moving-per-heat potential by just annealing and letting it cool…must have taken you ages.

Alan

Yes I am playing it safe . I have forged metal hot , it just is not as safe a cold forging. I also like doing things the hard way ...  Habaki looks good though...   James

Dorthy Steigler is a master of silicon bronze.  Google her and hold on.  I love the bronze because it is to forging what TIG welding aluminum is to welding.