Weight drop on bows due to moisture?

[Aksel]

You need to get a dehumidifier! That’s how I solved the problem. Placed my bows in a room that is not used and placed a dehumidifier there. I have a hygrometer and the moisture is always fine

Very good idea! I think this is the best solution.

Thanks and happy new year

[Selfbowman]

Here is a bow I built in 2018 won the mojam shoot that year. Then broke some records. I’m pretty sure   the moisture was at about 7  percent when I built it. It now weighs 26.2 oz when I built it it weighed 28 oz. Maybe different scales. The old one was a spring type with the round top where you set the bow now I have a digital . But there is a huge difference.  The moisture now is below 5.5.  It blew up doing a stretch test 1-1/2 -2 years ago. I think it got to dry. But can math be done to figure out how much say 1.5 percent difference would be in the bow?? Something the engineers can ponder. Arvin

[Selfbowman]

Even though the bow dried out some it did not go up in weight. I’ve noticed that bows get spongey in high humidity conditions. Just don’t have it’s same feel. This really shows up at twin oaks in July at worlds. I tell my shooters to change there gap about two inches when the heat ant humidity crank up.

[Aksel]

Here is a bow I built in 2018 won the mojam shoot that year. Then broke some records. I’m pretty sure   the moisture was at about 7  percent when I built it. It now weighs 26.2 oz when I built it it weighed 28 oz. Maybe different scales. The old one was a spring type with the round top where you set the bow now I have a digital . But there is a huge difference.  The moisture now is below 5.5.  It blew up doing a stretch test 1-1/2 -2 years ago. I think it got to dry. But can math be done to figure out how much say 1.5 percent difference would be in the bow?? Something the engineers can ponder. Arvin

Tim Baker claims a bow gains/looses 6% of strength/stiffness for every 1% of moisture it gains/looses. I worked it out and it makes a lot of sense in my case. Wood was too dry, about 6% MC when I made the bow in the example in the first post,  then apr. 14% in winter at 70RH.

I have now put a few bows in a PVC pipe with Christmas lights in it. Keeps RH at 45-50% and wood is drying out to 8.5- 9% MC