Thanks. Does he just burn a hole into the handle and put it in bees wax after? (In his video before this one he just heats the tang of his knife until it gets red hot, inserts it into the handle hole and then in the next video he just fills the hole with bee's wax and sets it in.) That is all that keeps it in place? It almost seems too simple.
There are a bunch of variations in how people like to do "burn in" wa mounts. I don't want to speak to Maxim's video or method (haven't seen it in a long time and not sure of all the steps he takes) nor do I want to try and say what the traditional method in Japan is....but a few things I can add in general about the process and how many will do it:
The burn-in process is relying partly on the heat cutting the opening to the right size and partly on the expansion and contraction of the wood (and metal) due to heating and cooling to create the strength of the mount. Wax is used to seal the tang hole and insure no water can get inside the handle where it might risk rusting or corroding the tang on carbon knives. Wax and sawdust can also act as a bit of a glue when added into the hole.
as to method. The general approach is to precut/file/drill the tang hole slightly undersized. The heated tang expands the wood fibers as its pushed in.
Variations --
Some like to insert and remove the tang once before seating it fully a final time.
Some people will add a little bit of sawdust to inside the hole (sometimes with wax) to further insure a tight fit
Some people will make a sacrificial tang slightly undersized to the actual one out of scrap metal to get the fit close before switching to the actual knife
when heating a tang, always hold the knife barehanded (no glove). You want to have sensitivity to the heat. If it gets too hot to hold, that is the warning sign you are heating too close to the blade and are about to potentially damage your blade's temper and heat treatment
while it looks simple to do a burn in, it's not nearly as simple as it looks. It is relatively easy to get slightly out of alignment or otherwise mess up the mounting.
also keep in mind, burn in mounts will not always work well on all types of woods. Trying to do a burn in with an exotic wood custom handle can be a recipe for trouble. If the woods' particularly dense it can crack (had this happen with an ebony handle)....
if the ability to easily remove the handle or replace it isn't a high priority, many people will use epoxy in their mount instead of a burn in approach.
personally I like the burn-in method but it's caused more than a few anxious moments when using it with a handle you've spent hours working on. Not being a pro (eg not doing it often or having the need to do it in volume) I tend to make a starter tang out of some flat bar. It adds a step and is much slower but it takes away the worry of damaging an expensive knife. Working with exotic woods, it also gives me a little more comfort that I'll get a good fit without damaging the handle I've made. For method: I trace the ouline of the real tang on it, grind it to slightly undersized...and use that to do the first pass of the burn in. For many that's unnecesary and extra work but it works for me.