Greg, For sinew wraps I use pitch varnish; hard, brittle pitch dissolved in alcohol. Use hard brittle pitch for this (Natural volatile oils have evaporated). if gooy stuff is used, the varnish will stay tacky. Some use plain gooy pitch to seal sinew wraps as it comes from the tree.
Collect the pitch from pine tree damage area. You have to heat it to melt it and to remove debris.
Also, cooking releases the natural volatile oils and allows the pitch to harden when cooled. You have to be very careful when heating the pitch. It is very volatile and will burst into flame if not watched closely. You will have to experiment with how long to heat. I heat it, cook for a while, let it cool and check the consistency. Make pitch glue sticks like Tim suggested.
When the consistency is good, re heat and mix in finely ground charcoal(for body) and bees wax(to make less brittle). Dried deer poop and rabbit poop does the same thing as the charcoal; adds body. I have also used fine saw dust for this.
The bees wax makes the glue less brittle so it doesn't shatter when the arrow strikes something. I think any wax or oil, like bear grease, deer fat, etc will do the same thing.
You will be surprised how sticky the stuff is. When hafting the points I drip some pitch in the arrow head slot. heat the point then push it into the slot and set it true. Let it cool and check for truness. If adjustments are needed reheat the point a bit, adjust, then let it set and check again. Even after wrapping with sinew and sealing you can adjust by heating the point a bit first. If you try to adjust cold, the bond will break.