Muskoka chair: cheap plastic vs poly lumber
They are both called plastic, which is like calling a canoe and a cruise ship both boats.
The moulded resin chair — the stacking kind at the hardware store — is made by injecting plastic into a mould. It is hollow, weighs about ten pounds, and is stiffened by ribs on the underside. It is fine for a season. Then it goes brittle in the cold, chalks in the sun, and one January it cracks where the back meets the seat. It also blows over in any real wind, because there is nothing to it.
Poly lumber is different in kind. Recycled HDPE is pressed into solid boards, and the boards are cut, drilled and bolted into a chair exactly as cedar would be. It weighs three to four times what the resin chair does. There is no hollow, no rib, no mould line. The colour is pigmented through the board, and the board is stabilised against UV all the way through, not just on the skin.
| The other | Greens.ly | |
|---|---|---|
| Construction | Moulded, hollow | Solid boards, bolted |
| Weight | ~10 lb | ~35–40 lb |
| In wind | Blows over, blows away | Stays put |
| Cold | Goes brittle, cracks | Unchanged to −40 |
| Sun | Chalks, fades | Stabilised through the board |
| Repair | Throw it away | Any board can be replaced |
| Price | $60–150 | $299 CAD, delivered |
How to tell which one you are looking at
Lift it. If it comes up with one hand and feels like a laundry basket, it is resin. Look underneath: ribs and a mould seam mean resin; boards and bolts mean lumber. Ask the weight. Anything under 25 lb is hollow.
When resin is the right answer
A single season, a rental you will not see again, a child's play area. For anything you intend to still own next year, it is the more expensive chair.
Questions
Is recycled HDPE the same as resin?
Same family of plastics, completely different product. Resin chairs are moulded hollow; poly lumber is solid extruded board, milled and bolted like wood.