This is where I started, It's a bit difficult to tell but the jacket feels dry and without any waterproofing to it. To apply the waterproofing I let it cool fully overnight, then with a rag I rubbed it onto the jacket then went over it with a hair dryer on hot to soften the mixture and help it run into the fabric.
This is what it looked like after putting the mixture on, but before running the hair dryer over it.
Here you can see the difference between treated (top) and untreated (bottom). It needed this pretty badly methinks.
When I was doing the seams I scooped up a small amount of wax with my finger and worked it into the seam by rubbing it against the seam so a small fillet built up along the whole seam. These took a little longer the melt in with the hair dryer, but I think it will help in the long run.
And here we are, finished. This took, probably 2 hours and the bucket of wax mix is still very full. As you can see from the last photo it looks like the wax is cracking where the material has bent. It isn't flaking off or anything, but it may reduce the waterproofness. To stop this happening I think I will add some more turpentine to thin it a little and see if that helps.
A quick word on turpentines. I used pure gum turpentine. This is the more traditional product made from the oil of trees. A cheaper alternative that most people are familiar with is mineral turpentine. This is a similar product however it is made from oil rather than trees. The mineral turpentine would probably work and if I had no choice I wouldn't hesitate to use it. However after standing over it for a few hours breathing in the fumes I am very glad I used the gum turpentine as it smells much nicer if the smell is going to be hanging around for a while.
So there you have it. For about $50 and a few hours of your time you can waterproof just about any porous material. The rag I used to apply the mix is a much looser cotton weave than the jacket and it is now waterproof as well.
If you have any questions or tips, please comment below so we can all learn something together.