Forge Welding With Hydraulic Press?

[Damastang]

G'day

Finally have my press up and running, it worked out better than I could have imagined. One thing that I am having trouble getting my head around though is setting welds in the press. Without the quick sharp blows of the hammer to blast it all out, wouldn't the flux and other crap be caught between the layers and prevent a weld? I made up a quick billet yesturday and tried setting the initial weld under the flatter die on my press. The heat and everything was correct and I gave it a light squeeze then straight back in the fire then a heavier squeeze. Upon letting the billet cool I could see several spots that weren't welded as they were cooling at different rates. I heated, re-fluxed then heated to welding heat and took it to the anvil and with a few good taps with my 4lb and a shower of sparks, the billet welded beautifully as it always has done on the anvil. Maybe it's because I use a coke (no green coal) forge rather than gas? Or is there something I am doing wrong? My press is 25 tons with a ram speed of 2.5" per second. I was thinking the press would be far superior for setting welds?

Cheers

[Frosty]

If you need the hot flux squirting out of the joint to clean it then you aren't getting it clean enough to start with. In a large lap or billet weld I shine all the matched faces as well as possible and flux them cold as I wire the join together. I only need a light sprinkle of flux, a BIT more than salting an omelet. Flux is NOT glue, it's primary job is to prevent oxygen from contacting the hot steel. With the joint wired tightly closed the flux will melt as it comes to temperature BEFORE it enters it's most vulnerable to oxidization state.

On the other hand if you're welding something that you can't clean and have to use a lot of flux to flush the joint use a crowned die upper or lower so pressure from impact strikes the center of the weld first. This will be a drawing die but very slight so it won't have a lot of effect unless you beat the snot out of it.

This is just how I do it, other guys are almost unfailing using different techniques.

Frosty The Lucky.

[Damastang]

Cheers frosty, I may be going a bit overboard with the borax . I leave my mating surfaces at a grinding wheel (angle grinder) finish with the grind lines running across the width of the billet. I would have thought the rough grind lines would help the billet to weld? When you say flux cold, what do you use? Sounds like a good idea.

[Dave Budd]

i don't have a hydraulic press, but I use a fly press for setting all of my billets. I find I get much better initial welds than using a hammer that way. It has also saved a few pieces that I couldn't get to stick back together.  Tool steels don't need to be as hot to weld as mild, so there is no need for big splashy sparks when you set a weld. The hotter it is then the more crud will form in the forge and also the more metal you will lose to scale, so IMO the cooler and less splashy I can do it then the better!

 

 I usually leave the surfaces of my metal ground, tack the stacks together and sprinkle with borax when it is warm enough to stick (a few hundred C?), then reflux at dull red. When it gets to a dull orange and the outer layers are wanting to open, I press it to bring everything into contact and then reflux. When up to welding heat I move quickly to the press and set the welds. A couple or three of those welding cycles and I start drawing it out.

[kayakersteve]

I use a hydraulic press for all of my forge welding and it works great - There are times I would like a power hammer though. 

 

[kayakersteve]

Forgot to mention I used bituminous coal converted to coke too!

[Frosty]

Cheers frosty, I may be going a bit overboard with the borax . I leave my mating surfaces at a grinding wheel (angle grinder) finish with the grind lines running across the width of the billet. I would have thought the rough grind lines would help the billet to weld? When you say flux cold, what do you use? Sounds like a good idea.

​I just sprinkle a little on, less than a powdered donut. I shine the matching faces up with y belt grinder if possible but a draw file works fine. Leaving the scratches doesn't hurt and may help. I sprinkle the flux on when I wire the pieces and seeing as I hold the piece in my bare hand to shine and wire it up, that's what I mean by cold. Hold it in your hand cold. I wire it tight enough the flux doesn't just fall out of the joint like sand in an hourglass. Then again I keep the joint flat till it's hot enough to turn over in the forge.

A technique I haven't tried yet is to shine the faces and perimeter weld with an arc welder leaving a small gap. Then while the billet is still hot from arc welding put a few drops of light oil in the gap. Capilarity will draw the oil into the joint and flux it. A light household oil like 3in1 though I hear of guys using diesel fuel.

Carbon has a greater affinity for oxygen than iron does so as it gets hot it scavenges any oxy from the joint and is driven out when the weld is set. That and the little bit of extra carbon that gets absorbed by the steel lowers it's melting temp at the joint boundary. The increasing C content at the joint is hearsay on my part but the scavenging oxy I know for sure.

Frosty The Lucky.

[will52100]

I've had good luck welding with the press, but the stack needs to be clean, and it's a good idea to have the grind marks going sideways so there's a path for the flux to escape out.  Normally I flat grind when doing a billet and either arc weld the ends and a handle on, or wire up.  I've gone to doing the first weld using diesel as the flux.  On some mosiacs I've taken to surface grinding the pieces before stacking.

Thing about a press is that it is slow, a hammer with a dome face will squish the metal together and squeeze out crud.  On a press everything needs to be pretty well clean and in close proximity to start with.  Not to mention that the thicker the pieces are the better as a press sucks heat fast.  When I'm doing a "Frontier" damascus, welded up from high carbn scrap one piece at a time, I do the welding on the anvil by hand as the pieces are odd shaped.

I've got a press and a hammer, and they compliment one another well.

[cliffrat]

The only reason I flux a billet is to know when the billet is ready to weld (the flux starts to boil), so I don't need much flux at all. I do not bother spending time sanding my mating surfaces bright and clean either. I simply spray the pieces down with acetone, (carburator cleaner DO NOT use brake cleaner, you will die!) to remove any dirt or oils, stack up the pieces in a drill pres vice, weld the ends, weld on a handle, and while the billet is still hot from welding, put it in a bucket of diesel fuel. Some guys use kerosene, but I cannot get that easily and found that diesel works just as well. Just don't use the agricultural diesel fuel, there is some sort of dye in there that jacks up the welds. Just visit the local gas station and buy the automotive kind. Does this work you ask? Take a look.

BTW - now I only use my press for forge welding. I used to use my 25lb little giant, and that worked great, but the process took all day. The press is so much faster and cleaner.

Edited June 12, 2015 by cliffrat
forgot something

[ianinsa]

Brilliant looking piece of Damascus, I'm definitely going to give the diesel trick a try soon. I must admit I always hand hammer billets prior to using the mill, press or powerhammer.

I suppose it's just habit(a bad one at that) but then I'm a creature of habit, I've got to get into a habit of breaking habits

[cliffrat]

ianinsa: I remember when I first started making Damascus, I had these books by Jim Hrisoulas, and I was trying to follow the method he taught. This involved setting the welds with a 2-1/2 lb double jack sledge hammer. I was miserable. I couldn't get more than like 7-10 pieces in a billet or it wouldn't weld, my arm was sore, and by the time I folded it twice, there wasn't much steel left. Then I met a very experienced knife maker, who looked at me like I was completely mad and said: "You have a power hammer, what the F are you doing that with a hand hammer for?" Then he told me to increase my initial billet size to about 20 layers and use the little giant. It was a major leap in my Damascus. Now I have the press and a whole new world of patterning is possible.

[dimenickel]

why not just do, whatcha did

set the weld on the first weld heat by hand, then 2nd heat go to the press to run along

i do exactly that but with a powerhammer...  set the weld by hand, then do it by power on the 2nd heat 

[cliffrat]

why not just do, whatcha did

set the weld on the first weld heat by hand, then 2nd heat go to the press to run along

i do exactly that but with a powerhammer...  set the weld by hand, then do it by power on the 2nd heat 

​So you can set welds in a 25 layer billet, by hand?

[dimenickel]

easily !!

you are just trying to get the plates to be in intimate contact with each other !    they stick and the diffusion weld will take place ... 

-then the more time your at weld temp, grain growth will sorta go through the weld boundaries making a strong bond ( i believe ) .. i usta have a great micrograph pic of this grain growth, really cool to see

you'll feel it under the hammer when the weld sets..  it will feel like the mass has become solid !  hammer it hard enough to set the weld  ( which is not very hard for me with a 4lb hammer )   afterall, at weld heat the steel feels like hammering play-doh !

well, this is just me..  and everyone has their own ways

[ThomasPowers]

Depends on how thick your layers are.  My typical billet on BSB and PS is 25 layers and I have no issues working them by hand.  A thousand pound billet would be different. (and there are folks who have worked such sizes out there!)

[Judson Yaggy]

BSB and PS?  WTF, IFGHPR.

[ThomasPowers]

Bandsaw blade and pallet strapping----discussed a bunch of times previously here as well as elsewhere.

[plain ol Bill]

A typical billet for me was 30 pcs. of 1/8" material (1084 & 15n20). Stack up all the pieces without grinding scale off, put a weld bead on each end and across the middle on both sides, weld on a handle, stick in the forge. When it starts to take on color pull it out and flux it w/ anhydrous borax, return to the forge. When the flux starts doing a crazy dance (bubbling fast and evenly) and there are no shadows in the billet take it out and into the press for a quick squeeze reducing the height by about an inch. Brush off flux using a stiff wire brush, return to the forge and draw under the hammer or press, cut, stack, repeat, repeat, repeat -----.