Improvement to Accuracy of Tilting Spoon Rain Gauges

[GT Woodin]

I've owned 3 of these over the years, most recently, the Davis Vantage Vue.
They've all suffered from the problem of incomplete emptying of the spoon upon tilt.
This means susequent tips will have a less than designed volume in the spoon, before tipping. In other words, these gauges over-read true rainfall.
To differentiate from Tipping Bucket gauges, these also have rainwater adhering to the buckets. However, as this is the same both sides, the error cancels out.
There are other reasons why TB gauges over-read, most commonly because the manufacturer has calibrated the gauge to read correctly at, say 2" per hour. If so, this will cause the gauge to over-read at low rainfall rates.

Onto my solution for tilting spoon gauges:
Remove from your ISS
Clean spoon under tap.
Dry
Apply Durable Water Repellant, (available from outdoor shops), to the spoon. Make sure whole surface is covered. Invert into kichen sink. Dry over a gentle heat (face down). eg: a gas fire top.
Replace ts spoon assembly in your ISS.

I immediately noticed an improvement in rainfall readings from the Vue compared to my check gauge. This is because water now 'beads' on the surface of the spoon. When it tilts, large droplets are more likely to fall off. The spoon is left dry.

Too early to give details, however the over-reading of the Vue gauge compared to check gauge, averaged 15% monthly.
Now, the readings Vue/check gauge agree within 5%.

Two unknowns;
How long before the DWR wears off, and requires replacing?
Will accumulation of sediment (rainfall pollutant, and blown-in debris) negate the improvement)?. To explain, sediment in the spoon will make water retention more likely. We're then back to square 1.
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[GT Woodin]

Update: One months readings showed a significant improvement following application of DWR.
At months end, 5" check gauge 147.6mm, Davis Vantage Vue tilting spoon 144.2mm, or 97.8%.

I did remove the Vue gauge, and cleaned it under the tap with a stream of water, then wiping with a paper towel.
This is to remove sediment.
Now replaced in Vue ISS awaiting next months rain.

[Len Wood]

This is impressive attention to detail in your measurements.
My measurements are just from a standard 5 inch copper gauge.
2023 annual total 1225.7 mm (117% of 30 yr average).
What was your total for 2023?