When varnishing over stained wood, how do you keep the varnish flat without risking sanding through the stain? Clearly my brushing technique leaves much to be desired, but when varnishing small boxes of stained poplar, I find it very difficult to avoid all errors-- too much flow on edges, for example, which leaves a line in the varnish. In the past, varnishing wood finished without stain, I'd just sand the error flat with fine sandpaper. If I try that with the stained boxes, it's hard to avoid sanding through the stain at the edges.
I'd be very grateful for any advice.
Ray