At what temperature does archery equipment become brittle?

Q

"At what cold temperature does archery equipment become more brittle and more likely to break?"

A

Depends on the material used in the construction of the archery equipment.

Fiberglass (commonly used in bow limbs) becomes brittle and increasingly brittle at a temperature of 0° C. For this reason my personal preference is to never do archery if the temperature is -5° C or colder. (That and I don't like freezing outside when it is super cold conditions.)

Carbon Fibre (commonly used to make arrows) becomes brittle at -60° C. So not as much of a concern.

Aluminum actually becomes stronger at colder temperatures. It is at high temperatures (above 100° C) that aluminum becomes increasingly weaker.

Leather, Feather Fletching, Glues, etc - Honestly, I don't know, but I am going to guess certain glues and epoxies do become brittle at low temperatures and that it varies on the type of glue or epoxy. Leather and feathers I would not worry about. Same goes with plastic fletching, I am going to assume that is pretty durable.

Wood is more resistant but not indestructible. It also varies on the type of wood being used, but the rule of thumb is that the harder a wood is, the more brittle it becomes at lower temperatures. So the problem here is that many longbows (and some other styles of bows) use various kinds of hardwood - and that typically the best hardwoods make really good bows.

Other factors effect how brittle wood is, like the following:

Moisture Content - Because wood contains water, when the water turns into ice it expands - thus damaging the wood itself. The higher the moisture content in wood, the more brittle it can become.

Type of Wood - Certain types of wood, like pine or spruce, are excellent for making structures outdoors because they are more resistant to water and ice damage. However pine and spruce is horrible for making bows. In contrast oak, hard maple, and other hardwoods are great for making bows - but are very vulnerable to water and ice damage.

Oils and Finishes - This protects the wood from gaining additional water content. A well oiled bow is more protected from water damage and mildew, but that doesn't mean it cannot be effected by ice damage from the preexisting moisture content.

Kiln Dried Wood vs Acclimating Moisture - Kiln dried wood has its moisture content reduces and if then sealed with oil and finishes, it will be more resistant to ice damage. However there is a problem... if the wood after it was kiln dried was given time to acclimate to the surrounding moisture content in the air before being sealed - or worse, it was never sealed - then it will have the same moisture content as regular wood anyway.

Treated Woods and Specialty Woods - Some woods are treated with resin to create brandname woods like "DiamondWood" and "FutureWood", like those used by the Bear Archery Co. The resins make the wood more durable and water resistant - and thus more likely to be able to take extreme colds. There is also woods like Accoya®* wood, which is treated with acetic anhydride, which increases the wood's durability, "dimensional stability" (whatever that means), resistant to rot, and makes very resistant to both water and cold damage.

* Apparently adding ® is more or less a requirement when talking about Accoya® wood. It is mostly used for outdoor purposes. To my knowledge nobody has ever made a bow out of it. It would probably be good for making arrows however. If anyone does make arrows out of Accoya®, please email me some photos and let me know how well they work.

Note - Nobody really asked the question, but I felt the topic needed to be discussed and that other people would benefit from learning everything above.