First when it was finished, I wrapped it with birch bark and stored the bow outside. It didn't work that well, it kept drying and were brittle and weak due to that. Then I took birch barks away and noticed a longitudinal crack at the center of handle. It started spreading if it was too dry so I had to keep it as wet as possible.
Then I found that pitch was used to make the compression wood more durable. Yesterday I then saturated the belly with (spruce) pitch. It is now drying and so far the bow hasn't gone deflex at all.
Going to post the results later...
