Wood Sample Testing

Photo from left: White PVC board / Cypress / Hoop Pine / Cedar / Merbau / Redwood / Paulownia

Wood Sample Test Exposure to the elements

I thought i’d throw a few samples of different wood together for some weather exposure tests. Alex of Spicers Hollow Native Bees is trialing some Paulownia and donated a few left over samples and also some PVC board that some box makers use, the rest of the wood is just what i had laying around.

I regularly use Cypress and Hoop Pine so i already know what happens to them over time when used for bee boxes and exposed to the elements. I am more interested to see how the Paulownia holds up when exposed to full weather over time for appearances and what happens to it when exposed to high moisture in the garden.

This might help with how we make native bee boxes, for example if we just use clear coat for a nice timber finish, but then in a few months the box looks terrible, we may just have to use paint.

If you’re using Paulownia for Native Bee Boxes I’d love to hear year view on the wood, please send me an email. https://www.nativebeehives.com/contact/

Wood list…

  • PVC Board – white
  • Cypress
  • Hoop Pine
  • Surian Cedar
  • Merbau
  • Redwood
  • Paulownia

I have made four sample boards,

  1. Placed in the garden where it might have a high chance of rotting
  2. Placed beside a bee hive, full weather exposed to some sun and rain
  3. As above, this one has a clear coating
  4. Placed in the shed, used to compare with the others

Update: 26/12/2020

12 weeks from the start and I’ll add updates here every few months.

Thoughts so far: A very noticeable difference with the Paulownia. It’s a very light wood, seems very porous, absorbs moisture, starting to mould, possible quick decay in garden.

It’s advertised as “does not absorb water / resistant to rot and termites”… have i got the right stuff?

Paulownia definitely needs more testing, possibly with many boxes over years with the high moisture environment of a Stingless Bee colony. It would need to be well coated and checked occasionally.

Chances are that it might go perfectly well as Native Bee boxes if it’s painted . The bees will coat the inside with propolis so the wood may be sealed off. I was intending to buy some and make boxes for my own use, but now i think i’d prefer to wait and do some more research before investing the time and money. The advert says it doesn’t absorb water so maybe it’s just the surface that holds the water causing the mould.

All other samples of wood seem unchanged. The Merbau has leached it’s stain everywhere.

Above: from left to right

  • White PVC
  • Cypress
  • Hoop Pine
  • Surian Cedar
  • Merbau
  • Redwood
  • Paulownia

Below: Closest to the camera from left to right:

  • Paulownia – uncoated – In the garden for rot test – signs of decay and mould
  • Paulownia – uncoated – exposed to full weather – signs of mould
  • Paulownia – coated – exposed to full weather
  • Paulownia – uncoated – stored inside shed

Update 11/01/2021

I saw a description for Paulownia that stated it doesn’t absorb water so that gave me an idea. I placed Cypress, Hoop Pine and Paulownia in water for three days.

I then cut the end off each piece to check if any water had entered the end grain. To me, Cypress looks like the one that absorbs the least amount if you look at the long grain surface. Paulownia appears to have absorbed water, possibly in equal amounts to Hoop Pine.

Horizontal end grain image – cross section after being cut – Cypress / Hoop Pine / Paulownia

Above image 3 days in water. Below image 14 days in water.

A little hard to see in a photo, the Cypress has taken on the most water and the piece of wood sunk. It looks like the fibres/grain have drawn water further in to the wood. The Hoop Pine has taken on more water than the Paulownia, though both have drawn in a fair bit.

It looks like the Paulownia may just have held water within the outside few millimetres and resists drawing water further in.

Return for updates every few months

*If you have boxes made from Paulownia I’d be interested in hearing how they’re going with bees in them.

Please send an email: https://www.nativebeehives.com/contact/

Check out the previous “Varnish and Oil Coating Test” article