Hi @Macrozzie,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
Hevea timber, also known as rubberwood, behaves quite differently from bamboo, which is why your benchtop finish has turned out rough after the first coat. Unlike bamboo, which is dense and smooth, Hevea has a more open grain and porous structure. When you applied the varnish, the wood fibres absorbed it unevenly, causing them to swell and stiffen. This raised grain is what makes the surface feel prickly to the touch. It’s a common reaction for many hardwoods after the first coat of varnish, so you haven’t done anything wrong.
The good news is that you don’t need to strip the varnish or start again. All that’s required is to sand the surface lightly to smooth down the raised fibres. Once that’s done, each additional coat of varnish will build up a smoother, more durable finish.
To fix the problem, wait until the varnish has fully cured, which usually takes at least 24 hours, and may take longer in cooler or humid conditions. Then, lightly sand the surface with a fine-grit sandpaper, like this Flexovit 100mm x 1m 400 Grit Sandpaper. The aim here is not to remove the varnish, but simply to knock down the roughness.
After sanding, wipe away all the dust with a clean cloth to ensure the next coat adheres well.
You can then apply another thin coat of varnish, brushing with the grain. As you repeat this process — light sand, wipe clean, recoat — the surface will become progressively smoother. Typically, three to four coats are needed for a benchtop to get both a durable protective layer and a nice finish.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
