How to forge weld

[Glenn]

How do YOU make a forge weld?

Walk me through the process as if I had never done this before. Give me the details to make it work the first time in my forge. Show me what to look for and why. If you have a camera, photo will help a lot in seeing what is going on.

Let's hear from several of y'all and then I can collect the notes and put them together in a blueprint.

[Strine]

What are we welding Glenn? Seeing as how you haven't done it before maybe we should start with a link in say 1/2 inch. 1/2 inch because it will hold a welding heat for a tad longer than smaller sections and a link because the parts to weld are in place at the time of welding. Fancy things like "dropping tongs" can wait till later.

Do your mathematics (note the s; you'll get it right everytime if you do the maths rather than the math ) and calculate how much bar you need for the link in question.

The first heat is easy, just make a 'U', keeping the sides at equal lengths.
If you're quick you might manage to get the scarfs done in the same heat. What's a scarf you ask? Well it's a thing to go around your neck in the winter when you go to the footy. Or... it's something common to a lot of forge welds where the metal is jumped up or otherwise altered in shape to allow for a better meeting of the faces to be welded. Generally a scarf will also allow for losses of material due to the welding heat, scale and the actual forging. Again we should work on the link because the scarf is fairly simple to make.
Making the scarf for a link depends on your handedness. I am assuming here that you are not one of these radical smiths that point their horn to the right if they're right handed. I assume also that my anvil nomenclature is at least understandable if not universal. Hold the 'U' at about 45 degrees to the end of the face, over the table. The far leg is just on the face while the near leg is well onto the face. Hit the far leg half on and half off the face and before each successive hit move the 'U' slightly toward the horn. Do this until you reach the end of the scarf. This should result in a taper that sticks out the side of the leg. Flip the link over and do the same on the other leg as well. Don't be disheartened, Glenn if this takes a few heats. The old chainmakers have probably got a chain snaking out the smithy door by now in the time I have taken to type this far.

Now bend each leg toward each other so that the scarfs overlap. Here's where the your handedness is important and has thus far been taken care of whether you are left or right handed but not if you point your anvil the wrong :wink: way. There should be a few little steps on one side of the scarfs...these should come together. The importance of this is evident when you come to actually weld the link. If the scarfs are on the wrong side the act of striking the link has a tendency to pull the weld apart.

Next, bring it to a welding heat and weld. So easily said, don't you think?
Maybe if we ellimnate a few sources of failure we can do it that way. A fresh fire works better than one that been going all day. If you are fumbling about at the forge and not real sure what to do at the anvil you are bound to fail. If you go beyond the welding heat for too long although it looks pretty there won't be too much of the link left. Its the rats in the fire. When you get it to the anvil go gently at first to make sure the weld has taken before any serious forging to shape. And beware the man carrying copper pennies.

Above all Glenn success at fire welding will only come with practise, practise and more practise. I am sorry to say it will not work the first time. If it does then I gladly say you're a better smith than me and venture to suggest you're better than anybodyelse hereabouts.

[HWooldridge]

Strine pretty much hit the salient points and either a chain link or faggot weld is probably easiest. People sometimes forget that the old time smiths almost always had some help for two part welds so a guy working by himself must be quite skilled (watch Bob Patrick sometime if you get a chance). I like to demo welding by taking a piece of 1/2" square, nicking over the hardy and folding back only about 5/8 or so in length. Bring it to temp, flux, weld, forge into a square lump and finally shape into a round snub. It will split if a bad weld. We have a fellow in our local group who has taught several people to forge weld successfully and he always starts with a chain link, then has them make at least 5 assembled links. By that time, the student should understand the basics.

Adding to what has been said, a clean fire is important (coke or coal), proper flux and moving promptly when the time comes. Remove any clinker before starting. Proper fire color is entirely dependent on an individual's eyes so is a little hard to describe - to my eyes it is when the fire is a bright white-yellow and the material is the same color. Some people use the flux appearance - when it is flowing freely, time to weld. It's also very convenient if your gas forge will get hot enough because that eliminates all the problems with solid fuel fires.

When it's hot enough the weld will be incandescent and almost always makes a "SPAT!" noise when struck. It also feels soft under the hammer - not like when typically forging. If it is sparkling like the 4th of July, it is burning and probably will not weld - in fact, it likely won't weld on subsequent tries either.

Once it sticks, don't forge down to size below a bright yellow. The metal is moving around and can be split by cold hammering - even if it was a good weld to start. It is also perfectly acceptable to take a second or third heat to finish.

These thoughts are for mild steel - I hope JPH relates his knowledge on damascus and pattern welding.

[yesteryearforge]

Footy ???
Beware of the man carrying copper pennies,????

[HWooldridge]

Don't know what a footy is - unless it's a local bar :wink: ...but some folks consider copper to be poison in a welding fire. I have heard pro and con on whether it makes a difference but in any case, I don't put pennies in my fire.

[Strine]

Great idea re the faggot weld H. It would be so much simpler for Glenn than a link. Forge welding has something to do with the project at hand but for the most part it's all the things that experts do subconsciously that makes for success. You are correct, it is very difficult to describe at what point to get to the anvil and start hitting your job. My advice to Glenn is to find one of these experts and study intently the process then practise under his watchful eye. Question him about every aspect.

I remember watching a bloke weld two bars to make one long one. He only dipped the tip of the scarf into his coffee tin of sand, repeating this a number of times. As far as I could tell the rest of the scarf received no flux at all. His reason - it kept the thin tip of the scarf from burning before the rest of the material had reached welding temp. His description at the time was simply dip the scarf into the flux. That could have meant dip it into the flux all the way to your elbow joint.

And Footy. Australian Rules Football. A game for men
http://www.footy.com.au/dags/FAQ1v1-5.html

[Shane Stegmeier]

Here are the salient points that I didn't see covered so far...

Proper welding heat is often described as a sweating heat, the metal should look slick and shiny, once you spot it you will know what it looks like.

You can cheat a little and use an 1/8 round rod with a point on the end, you stick the rod into the joint area (While still in the fire...) and if it feels "sticky" then you are at welding heat...

It is very hard to weld on a COLD anvil:-), or even just welding thin stuff on a big anvil. You can warm the anvil in the spot where you are going to weld by laying a hot piece of stock on that part of the anvil and let it suck the heat out of it... Or you can use a welding anvil saddle (basicly a hot piece of plate or heavy bar that fits over the anvil face, and you weld on that so you don't loose your heat. You can also set a small anvil in the forge, and weld next to the fire (I have used pieces as small as 2.5" diameter shafting that was just a few inches long)

You can also "pinch weld", small stuff that it is hard to weld on the anvil, just pinch the area you want to weld with a pair of tongs in the fire or right out side of the fire. Otherwise the weld is prepared the same as any other.

Placement in the fire is important, as well as how strong a blast of air you are using to get to welding heat... Too deep in the fire and too strong a blast, and you will be getting too much O2 and you will be oxidizing your potential weld, making it harder to stick it, requiring more flux. Most people recommend bringing the piece to heat slowly to insure that the stock is heated to welding temp all the way through. (Of course this isn't truely neccessary, since in a coke forge with a good blast you can do several welds prettty snappy. But till you get used to things it might help:-)

The scarf is designed to match the two pieces up neatly, and blend well once the weld is completed. Upsetting or jumping up the area to be scarfed is done so that the weld can be forged out somewhat and still maintain stock size. Intentionally overlapping your scarfs when you weld can do the same thing if you are careful, but requires a different shape to your scarf and tip, and practice. The shape of the tip of the scarf is different depending on what you are welding to what??? Welding to square stock? Then the scarf should have a slightly rounded thin tip, and be the width of the stock. Welding to round stock? Then the tip of the scarf should come to a point. The scarfs should match pretty closely in angle and in length, the tip of the scarf should act as a standoff, till you get your welding heat and stick the weld. The "cleaner," "smoother," and more well matched the two scarfs are the easier it is to weld. Stainless will weld at room temperature IF both piece are machined and the tolerances are TOO close:-) (Titanium as well:-) A freind of mine used to machine quarter turn pool cue joints for custom pool cues, got to the point he was intentionally sloppy on his tolerances after he twistd shut a beautiful new joint, and was NEVER able to unscrew it:-)

Welding hints for patternwelding...

Flux before you are up to even a working heat... Let the temper colors run, and before you start to scale flux, flux, flux...

Flux is cheap:-)

Flux one side until it runs out the other (when you are at, or near welding heat), then flip it over and do the same thing on the other side...

If you are folding your billet to build up layers, after you nick it to make the bend(s), I like to quickly grind the faces to be welded together, then fold and flux and bring back up to welding heat. This way I can check for problems and, have a smooth clean face to weld. If you are using a ton of flux, and or a very agressive flux, this probably isn't neccessary but I like to keep track of thing as I go...

If you get to a sparking heat and you have 1095 in the mix you can probably just throw the knife away... Other steels are less hot short and are harder to ruin:-) And you can get a good weld AFTER a sparking the piece, wait for the sparks to disapear, then try the weld. You will have burned up some carbon and possibly ruined your steel, but you can get the weld to go. (If you BURN and kill the steel you might not be able to get it to weld but even if you did, the quality of the steel is ruined... so what would be the point... :-)

[Leah]

One thing I do is save a little coke from each fire and use it to "feed" my fire when I am welding. It really helps me keep green coal out of my fire. Green coal will not only add impurities to your fire, it will also cool it off.

I would love to see information on the different types of scarfs for different welds. A simple drawing would be great.

[mike-hr]

When jump welding, sometimes it works good to scarf as normal, then blind rivet the two (three, four) pieces together. Drill a 1/8" hole thru both pieces in alignment, countersink the holes a bit, and cold rivet a 1/8" pin into the countersinks. Now you're only handling one iron in the fire, and have guaranteed alignment. The rivet dissappears into the weld.

[Nolano]

Well, I just did the first thing that could be called forge welding.
It was mainly a test to see how hot my foge got. I bent a piece of square stock over on itself, and heated it to welding temperature. in two heats, I had a slightly shorter bar stock, that was thicker on one end. That wasnt very hard, but I doubt it counts as forge welding.

[Swamp Fox]

The weld counts.

Now do it again, not folded over on itself, but two ends overlapping. Make a good weld and then put it in a vise and try to break the weld. Report back with the results :wink:

[T-Gold]

I'm not much of a forge welder yet, but I'm starting off with faggot welds as described -- I like to test them by grinding or cutting off the "hinge" and putting the welded-on part in the vise and hitting the "original" bar. So far, so good... :)

[Nolano]

My forge welds(connecting two pieces) have been unsucessful. I am unable to hold both pieces steady while hammering.

[HWooldridge]

Nolano,

Bob Patrick is one of the best smiths I have seen at forge welding. He takes the two pieces and pushes the scarfs together before picking up the hammer. The parts have a tendency to stick a little and can then be gently hit until they are stuck properly. He also does this without letting them touch the anvil, which sucks the heat out pretty quickly.

You might also try a dot of MIG or stick weld on the side to hold the pieces together before finishing. If it's a good forge weld, the rest of the scarf will close up - if not, it will break apart. After you get used to seeing what a good two-piece weld looks like, you can go to putting separate pieces together.

[Nolano]

Ah yes, I need some flux, that will probably help. And I'll try heating the anvil a bit, with a piece of hot stock, or maybe with a mapp gas torch(I'll be careful).

[mike-hr]

Nolano, There's a few very good smiths in the Eugene area. David Thompson is amazing. There's an old hippie named Conrad(can't remember his last name), who would be happy to work with you for an afternoon. There was a guy at saturday market who made good stuff. An afternoon with another smith is a great learning tool for both involved. Look around, they're out there.

[Nolano]

I know Conrad Hodson, he is my teacher. I have a lesson with him in a few weeks, and I'll ask him about it then. Im just now starting up, so I think knowing that I can faggot weld is pretty good.

[SReynolds]

see some stand by the theory that you can't make a weld if the steel sparks.........................thus I'm not apt to believe what folks type.