To look at a Viking Knit chain is to see something seemingly complicated, but really, it is a series of easy peasy steps. The hardest, unfortunately, is starting. Many give up on Viking Knit because they can't get a good start, but trust me, if you can live with chaos at the start of your creation, it can easily become your favorite TV-watching activity, maybe even more than knitting. This is not a thorough tutorial; rather, it is for the student who has tried it before and failed. I implore you- try it again!! Buy some cheapo wire to start with, then once you get the hang of it, switch to fine silver, 24 or 26 gauge. You'll surprise yourself.
Look at the above Viking Knit chains. You'll probably see some variety. There are lots of variables to making one- many choices to be made:
a) gauge of wire
b) number of loops around mandrel
c) number of rows to weave wire through
You can see in the above pic, the chain running North-South on the left side- that is a knit chain that hasn't yet been pulled through a drawplate. The drawplate has a series of holes, ever increasing diameter, in which the chain is pulled and the diameter reduced, thereby eliminating the horizontal lines visible in the chain. It's easy to make one with a bit of spare wood, drilled with holes 1/8" to 3/8" in diameter. Chamfering the sides of the holes at the entry point will help, too. When the 'splines' of the chain meet, with no horizontals visible- then you've done it. You can see from the other chains above that you see no horizontal spans of wire- just v-shaped splines. Some are more dense than others- this has to do with the b) and c) variables- the more, the denser.
I would stick with 24 or 26 ga. of wire. Want to do a quick chain- choose the larger-diameter 24 gauge. Want a finer and possibly denser chain? Choose 26 gauge. Anything thinner will drive you crazy. Any thicker- hard to work with. Number of loops around mandrel? To start, at least 4 but more than 6 is difficult. 4 will look more boxy or square, 5 and 6 more of a rounded chain. Number of rows to weave wire through? Well, your choices are 1, 2 or 3. If you look at the above pic, the shortest piece of wire- in the center- u-shaped and copper colored- starts from the right side open and lacy- that's 1 row. Then it increases to 2 and finally a short segment of 3. This really is about density. To achieve this, you thread your wire through the crossing of wires not directly above, but the 2nd or 3rd row above, depending on desired density. Try it a few times and you'll start to see increased density in your chain.
This above diagram is one I created when I was teaching Viking Knit. I also have a left-handed diagram- email me at firstname.lastname@example.org if you'd like one!
There are many options for mandrels- when I learned my teacher created L-shaped mandrels out of steel bar stock. I also tried wood. What I found works best, are knitting needles. I cut them (with my jeweler's saw, but a separating disk or hacksaw may work too) about 6" long, then cut a notch about 1" down from the top. The beauty of knitting needles is they are inexpensive, come in lots of diameters, and are lightweight. The notch just needs to be a gap in the surface- about 1/8" to 1/4" wide- this is necessary in order to weave your wire end through the existing chain- always work over the notch! It will give you room to work. So, as you find, you'll always be turning your work in order to always be threading wire over the notch. A rule of thumb is- pick a diameter mandrel that you want your end chain's diameter to match. The chain will always be larger than the mandrel until it is drawn through the drawplate- then it's diameter is reduced.
There are lots of ways to start a chain- the above wrapping, creating a loop down, wrapping to secure, and repeating until the desired loops are created, has worked for me. You can google other techniques. I also start with a cheap, junk wire before switching to silver, because I usually cut off the front 'messy' end anyway.
Another difficult thing to do is to splice a new piece of wire into the existing length- I usually use 3' sections of wire, and I sort of twist the 2 ends of wire together, about 1/4" long each, continue to do a few loops, then trim once the new wire section is established. This splicing can occur a number of ways- you may find a way that works better for you.
Finally, trim the ends, use a heavier gauge wire and create a 1/4" long bend or 'hook' at the end of the wire (say, 6" long) and grab the end of the chain a few rows down and thread the other end of the wire through an end cap with a hole on the end. Make sure the end cap covers the hook completely. Make a loop to attach to your lobster clasp or toggle, and repeat on the other side with the appropriate finding.
The lesson is: don't be scared to experiment, fail, and make a mess- eventually you'll get it!! Once you do some, you'll notice that the chain will look messy, but pulling it through the drawplate will 'clean it up' quite a bit. Also, you'll start to notice intricacies in keeping the spacing equidistant between loops and will figure out how to achieve that. You'll also have to keep the force you're using to pull the wire into a loop tight, but not too tight. I find I use broad strokes of my arm when I'm threading and pulling wire. It's almost calligraphic-looking and helps to avoid kinking or overly-bending/stressing the wire.