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Canister cracks

David F

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Hi can anyone help me with my canister making please. I’ve made a billet of 1085 powdered steel and this time I’ve just used fish hooks I’ve used ball bearing 5mm in the past but have had similar issues . I’ve used a coke forge and got the can up to temp then hand set it turning it onto each edge and hammering it down to what felt very solid . When I’ve opened it up about an inch and a half at either end is perfect but I get this in the middle every time can someone please tell me what I’m doing wrong 

thank you all in advance 


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Can't download movies at this time, but suspect that you need to soak can at welding temperatures longer.  For a typical 1.5 or 2" can soak times at even welding heat on the order of 15 minutes aren't out of line.  Might be harder to maintain an even heat in a coke forge for that long.  I suspect a larger fireball and radiant cave configuration will be in order, but can't be sure as can't view videos.

Consider also posting a few still shots next time.

Did you carefully preclean nonpowder materials before assembly? Are your cans brim full and tight before heating?  How are you compacting (hammering pattern)?  Keeping at full welding heat during any compacting?

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Hi latticino 

thank you so much for your response it is truly appreciated. Yes the cans are filled to the brim I take them out strike one side do a single rotation on to the next side strike and so on hitting all four sides . I tried to draw out the pieces that seemed solid but they two began to fracture and crack . It is a bit difficult with the coke as you can’t see exactly what is going on one minute your ok the next you’ve gone to far . I plan on building a gas forge in the next month so I might wait till then to try again when I can actually see the can and what is happening to it .again thank you for your help 

kindest regards


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I was able to download the videos at work.  Your cans are a lot smaller than I expected, so extended soak times shouldn't be as big a deal.  I'm now guessing that you are forging down at insufficient weld conditions at some point.  Either cleanliness (O2 scavenger might be worth investigating), temperature, or pressure are lacking.  I'd go for a long soak at welding temperatures before any compaction, and use of a heavy hammer to project the blows as far as possible into the can. 

When you weld on the cap to the can does it fit inside the tube used?

Are you using any kind of resist on the can walls (whiteout) and are you absolutely sure it is dry before closing things up?

Do you ever include upsetting blows for the length of the can?

Needless to say, a fly press or hydraulic press might be a better option to compact from both directions at once.  I would consider at least using a bottom and top tool with a striker to compress from multiple sides (or just use SCH 40 pipe instead of square tubing and half round top and bottom tools).

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Welcome aboard David, glad to have you. If you'll put your general location in the header you'll find out how many members live within visiting distance and heck you might have someone to show you rather than tell you how to canister weld. Hmmmm?

Are you hammering flat on the anvil face or do you have a V block? If you're hammering flat the canister will spread sideways under the blow and not be compressed as much as it might. The center of the canister doesn't weld as easily as the ends because the welded end caps offer another dimension it can't move towards while the center can compress material towards the ends with less resistance. The material itself being relatively free to move you have to trap it to compress it. Make sense?

A set of V blocks are easy to make by welding two pieces of Angle iron V down on a piece of flat stock, one bottom tool the other the top tool. I like 1/2" for the plate and the Angle as thick as I have available, mostly 5/16" in my pile. Anyway, I stick weld the angle iron on the inside, tack it on the inside FIRST of course. Tacking shapes on an inside angle draws the joint together more tightly as the weld pulls cooling. 

With two pieces of angle iron welded side by side in a M shape you have your V blocks. Thee top tool should probably have a thicker striking plate but 1/2" doesn't warp too quickly. 

V blocks as seen on IFI compress a square canister equally on all 4 sides improving compression of your billet stock. 

You're better off over soaking at temp than too little, the canister prevents oxidization so decarb isn't such an issue. Frankly I don't work about decarb as I like powdered charcoal both as a oxy scavenger and as flux. However light lub oil works well and is a common scavenger, 3in1 works a treat. And being mostly carbon oil limits decarb and acts as the same kind of flux as charcoal. 

Frosty The Lucky.


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Hello Latticino,Thomas,Iron Dragon forge and Frosty 

Thank you all for your kind welcome and great advice . Yes I am using white out in the cans and I have just learnt through Frosty about oxygen scavenger,s and will definitely be making a V block set up for my next attempt.  Again thank you so much to you all for your extremely helpful advice I have learnt a lot from you all

Kindest regards

ps Australia Frosty near Melbourne is where I live I will fix my header up now

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