fluxing billets, where and how much?

[Knifemaker87]

hey everybody..
i have been wanting to try my hand at a laminated billet... but every time i try it doesnt weld. i think part of my problem is that i just havent been getting it hot enough. but that aside, when making a layered billet.. where do you flux, and how much? do you need to put anything between the layers? i have been reading up on this.. and just read Don Fogg's "tutorial" on damascus.. any tips for a newb?

i have made a little cable stuff... but i want to try layered stuff.
thanks
~Chris

 

[scottickes]

I "make sure" that I have flux one the ends and sides where the seams between the pieces are. However, I do coat the entire billet.

In addition, you can try mig welding thin strips all the way around the sides and ends, sealing up the billet. It's a modified can version of pattern welding. I use the same material for the sides and ends as the material on the top and bottom layers. For me that is 1084 on the top, bottom, two sides and two ends. Before mig welding the last end piece on, I drill a 1/8" hole in the center of the piece to let oxygen escape during the heating and forge welding process. I mig weld my rebar handle to the opposite end from the one with the hole in it.

I fill the billet up with WD40 through that little hole. The WD40 burns off any oxygen left inside the billett, and becomes carbon, which is good.

With this method, there is very, very little chance of oxygen being present in the billet, thus iron-oxide scale doesn't form between your layers. It also allows you to weld at significantly lower temperatures! I've gotten welds at temperatures as low as 1950 degrees F. with this method.

The thinner the side pieces are, the better, for the look of your damascus. If they are too thick, you end up with a frame around your billet.

The draw back is that the first time you have to fold it, you're back to a regular, open aired fluxed weld situation. You can somewhat overcome this by cutting the piece in half and when restacked, mig weld the seam shut, except for one little hole in the end for your escaping oxygen and WD40 or replate it. Don't worry about this bead of weld on your billet, because you'll be wanting to grind that layer off any how, to get rid of the picture frame look of your eventually finished billet.

This way works for those that can't quite get all the way up to welding temperature, or have trouble with the normal method.

Good luck.

Ickie

 

[deker]

that sounds like a lot of work Scott!

I personally spend the time in surface prep. I grind ANY and ALL scale off my steel and get the pieces reasonably flat. Then clean with acetone just before stacking. Tack the ends with a wire welder and stick a handle on.

Then, heat to cherry red (well below scaling temps) and flux the "sides" of the billet where you can see the layered steel. I don't stress over the ends much since I cut them off after the first weld anyways. Since you cleaned up the layers well to begin with, you don't need to worry about having flux able to get between anything to clean it out. I use just enough so that there is an even, glassy appearance to the sides of the billet. To my way of thinking, flux serves mostly to keep oxygen off of the billet. Using more than you have to just adds crud that COULD get into your weld.

The I heat to welding temp and set my weld with a hand hammer. Then, IMMEDIATELY brush off the old flux and quickly lightly re-flux the sides. Then I drop everything back into the forge to soak at a welding temp for 5-10 minutes (depending on billet size) before drawing anything out. Sometimes, if it's a tricky weld (4 bar composite, etc) I'll run a second "weld setting" pass just to make sure.

I've only ever had one billet fail and delaminate using this method. I had another start to delaminate at the edges, but that was my fault for not grinding my twist COMPLETELY clean before drawing it out into a blade.


-d

 

[scottickes]

The only reason that I described this method is because it works at much lower temperatures than the traditional way that you describe. I do it the way your describe now, but made of few of the modified cans when I was just beginning.

Once I began cleaning everything up and using good flux, etc. I began having more success with the traditional way.

I find that with the modified fabricated can method though, that it's almost impossible not to get a good weld. Heck, you don't even need flux!

Ickie

 

[Erik Fritz]

get a really long spoon when it starts getting some color flux it in the forge so that it is never exposed to atmosphere. this little tip alone is what has saved most of my billets from being junk.

 

[JCaswell]

I use two methods depending upon what I'm doing.

For initial weld up (many layers using a press) I'll clean all surfaces scrupulously (some guys don't do this, but I usually do high-stakes pieces and you don't want to blow 500 hours on a little inclusion that shows up at the very end).

Then I'll weld the ends with a stick and jump it to a 'handle' (rebar or square tube).
Then I'll cook up a pot of laundry borax. "Super saturate" borax into water at boiling point until it won't take any more. Then set the billets in and let it cool. This forms what looks like rock candy in Borax all over the billets. I take them out and let them dry (overnight) then knock the majority of the rock candy off (it has already made it through the layers and that isn't coming out).
Then I wrap it in SS tool wrap, heat it to welding temp (it is very important that it's hot enough!!) and squish it in the press. I forge from there as usual.

If I'm doing 'open-air' welding of, says, a few twisted billets together or putting the edge around a sword core, I stick with the traditional method of careful flux and heat control:
Heat it 'til it just barely begins to glow, take it out and flux it lightly (I do top and bottom), put it back in and run it right up to full welding temp. and weld it with the hammer.
If doing a section that's too long to weld in one shot, I'll put the piece back into the fire for a few seconds after welding and get it hot again, take it out and wire brush the old flux and scale--especially away from the unwelded area. After brushing, the unwelded area is about hot enough to receive a light dusting of fresh flux. I'll do that and in it goes again for that section's weld ... and so on. Flux only the area you intend to weld next.
It's important to try to keep the unlwelded section from getting too hot (you don't want to run the unwelded area up more than absolutely necessary) and to try to keep flux out until you're ready to weld that area. Burnt flux is counter productive!

Good luck--You can do it!

 

[burke531]

make the billet and put it in the forge. clean the layers if you feel it is neccessary. (its' not) when it starts to turn red do what Erik said and flux it in the forge. about a teaspoon full on each side. heat it until the flux starts to boil on the billet. depending on the size of the billet (mine are six by six by one and a quarter inches) let it soak at the boiling temp for at least 30 minutes. to make sure that it is hot enough to weld take a wire coat hanger apart or use a tig welding rod of mild steel and touch the hot billet. when the wire turns orange yellow it should stick to the billet and need to be twisted to pull loose. Go drink a glass of ice tea or bottle of water and come back put a little more flux on the billet and let it melt and start to boil. take out the billet and quickly brush it with a wet wire brush and then hit it moderatley with a hammer for the entire length of the billet return to the forge and reheat, the long soak can be omitted just let it come back up to heat. repeat hammering and heating until desired dimensions are achieved. If you cut and restack repeat the long soak on the first heat. I grind billet clean between cutting and restacking to insure that there is no trapped flux in my billet. if the wire sticks to the billet when you probe it then the billet will weld. Make sure and let it soak.

Bill

PS. MAKE SURE AND LET IT SOAK.