I’ve added a couple of new products to the list. Doug Irvine uses the Intergrain Heavy Duty finish on his finger joint boxes so I thought I’d give it a try. I’ve also recently been trying the Weatherfast Poly Clear.
The best long lasting coating is exterior white paint but the main objective here is to find a decent clear coat that shows off the wood for the longest time before the coating and the wood starts to age and look dull or grey.
All my money is literally on the Intergrain Heavy Duty, because it costs $70 for 4 litres of UltraPrep and $153 for 4 Litres of Heavy Duty.
The previous test was done is 2016 – Link here: https://www.nativebeehives.com/coating-test/
Products:
- Intergrain UltraPrep + Heavy Duty
- Norglass Weathefast Poly Clear
- Intergrain UltraDeck
- Intergrain UltraClear
- Feast & Watsons Tung Oil
- sample 6 uncoated
3 Sample boards:
- Kept in the shed fully protected
- In the shade but still exposed to rain
- Exposed to all weather, sun and rain
6 months later! June 2022
- Intergrain UltraPrep + Heavy Duty: Lasting well
- Norglass Weathefast Poly Clear: Looks to be deteriorating, bit disappointed about that as I thought it was going to be a good one
- Intergrain UltraDeck: Lasting well
- Intergrain UltraClear: Lasting well
- Feast & Watsons Tung Oil: Gone – no surprises there
- Sample 6 in uncoated
Two and half years later – September 2024
Heavy Duty and Ultradeck are still going well, though I would say if you wanted the box to retain a nice finish I’d recommend a light sand and re-coat before two years.