I turned some double front Carhartt pants into oil skin upland game pants.

Step 1: Get Some Pants.

These are Carhartt double front heavy duck pants. About $50 new.

Step 2: Make Some Goop.

- Beeswax
- Boiled linseed oil
- Hot plate
- Pan you don't mind trashing
- Cheap paint brush

Roughly equal parts wax to oil but a little heavier on the oil. Makes it spread and penetrate better. Heat it up to just past melting but be careful it will smoke easily. If it's too cool it will harden faster then you can spread it.

Step 3: Spread It On.

Work in small sections. Get your seams well.

Step 4: Apply Heat.

I've heard of some cats using hair dryers or torches. Have fun with that. I used this heat gun and it worked pretty slick. Hang on to the gun receipt. The first one didn't like this much work.
Work your way around your article however seems best. Apply enough heat to melt the wax so it is absorbed into the material and a little beyond so it starts to boil back up just a bit, then move on.

Step 5: Get It All.

Don't forget the sides and crotch. I did not go all the way inside the pockets. Apply some more to areas that look streaked and reheat. The final product will come out feeling waxy and greasy (go figure), get out there and do some good bush whacking and it will work itself out. You can practice first by making the goop out of toilet bowl rings and linseed oil on an old canvas bag or sneakers.
*Side note* Any breathability your material might have had will be gone so be ready to get a little clammy, especially as they get broken in.

Now quit reading about it and go do it!

Step 6: Things I Done Learnt

It's been a few years since I published this and some better practices have come about:

1. Don't use brand new pants.
The pair I used in this example were and I can't get them to loosen up for the life of me. I've made a few other pairs since, out of old loose Carhartts, and they turned out great.

2. I've landed on a better recipe.
Unfortunately the last time I made a batch was a year or two ago so I don't remember exactly, but I believe it was 3 parts oil to 1 part wax. That seems like a lot of oil as I write this, but I was making it in 12 oz batches and I know it wasn't 3 parts wax. Try it out, see what happens.
I also got some raw linseed oil to try which I'm looking forward to as boiled has chemicals I was unaware of.

3. Throw them in the dryer.
I have a sacrificial pair of Carhartts that I toss in the dryer with the new waxed pair. The unwaxed pair will take up some of the excess. It's not a lot, they won't become all waxed and stiff themselves, just enough to even things out.
I use low heat but milage may vary.
I've not had any problems with it in my dryer but if you're concerned, go to a laundromat.
Takes about 20 minutes or so.