beginner to brushing varnish

[nick brigg]

is it correct to do the edges first, then flow the varnish on the top surface? and what to do with runs off the edge...do i go over them with the brush or sand them out when the finish it dry? thanks guys!

[John Schreiber]

Try to avoid the drips in the first place of course, but they are a fact of life at least for me. I think you are better off brushing them off than letting them dry then sanding them. Since the drops are thicker than the rest of the finish, they will take the longer to dry and it is likely that the varnish will not be fully cured there. When you try to sand them down, I found that it often results in a ragged hole and a likelyhood of sanding through the finish.

[Rich Engelhardt]

Hello,
Do the sides (edges) first. Let the varnish dry completely. Do the top surface after the sides are completely dry. Use a clean cloth to remove the material that drips over the edge.
Don't try to brush it out.
The slick surface of the dried varnish on the sides makes removal of the drips easier. It's a two edged sword though. If you brush the material out on the unsanded sides, it will weaken the bond and lead to chipping of the finish.

With lacquer and shellac, the technique is reversed. Do the top first, then finish the edges off while the material is still wet. With lacquer and shellac, you do want use the brush to remove/spread the material. You don't want to use a cloth or anything else that can remove the material.
The reason is that lacquers and shellacs will soften the previous coat.
Trying to remove the excess will result in a blotchy rough finish.

Waterborne's are best treated as natural varnish.

As John said, don't let the drips dry, thinking they can be sanded out later. That seldom, if ever, works out.

Drips are actually a good indicator that you're doing things right. Your varnish should be applied as evenly as possible across the entire surface, in one continuous stroke. If you "let up" at the edges, you're going to have brush marks and/or an uneven finish around the perimeter.

[Steve Schoene]

The first thing is avoiding runs off the edges in the first place. The key there is always brushing off the edges, never onto them. Secondly, thin coats are generally better than thick, so that if you are getting more than the very occasional runs off the horizontal surface you may be trying to put too much varnish on.

Varnishing is a multi-step process. First you have to lay on the varnish. The traditional method is to brush across grain while applying the varnish. Then the varnish is spread and evened out by brushing with the grain. None of this calls for anything very critical. Properly thinned varnish won't have bubbles and brush strokes don't matter much at this stage. The critical stage is the tipping off, where a very light hand with a nearly dry brush is used with the brush held almost vertically. Then long, smooth strokes just kissing the surface give a varnish surface so smooth that it almost instantly levels out any remaining hints of brush strokes. You have to adjust speed and how big an area you block off by how fast your varnish sets up, since you need to maintain a wet edge.

You do want to remove any drips that do occur on the edges before they set up. But if you miss something then the best way to remove it is with the very light application of a card scraper. Steel wool won't work at all, and sanding, even with a block, is pretty tricky to get right so that the thick place is removed without excessively thinning an area surrounding the run or drip.

[nick brigg]

so...brush the top then get the edges? and how exactly do you brush off the edge...but not onto it...like stopping shy of the edge?

[Steve Schoene]

Start just shy of an edge, make a short stroke off that edge, and then make the long stroke off the other edge. You can carry the brush past the edge as you leave the surface, the brush will stop depositing varnish when the pressure goes off it. But when starting a stroke, if you brush onto an edge it is like scraping the brush off on the side of the can and leaves a drip on the side.

It might be an ideal practice to do the sides and let them cure before you do the top, but since this doubles the time it takes to do a piece, I've always just worked carefully to avoid problems, not always with complete success, but never with disasterous problems. The real problem with runs is on vertical surfaces where an unintentionally heavy coating sags in a sheet or "curtain." Avoiding that is just a matter of getting the right feel for the varnish and continuing to inspect the work until the varnish has actually set. Again it's the card scraper that bails out the problem, likely with an extra day to set between coats. The worst is when the supposed final coat becomes the penultimate coat because of a problem like that.

[Rich Engelhardt]

since this doubles the time it takes to do a piece, I've always just worked carefully to avoid problems, not always with complete success

Hello Steve,
Honestly, in pratical terms,,it more than doubles the time -doing the edges and letting them dry - but it's hard to say by how much. I could probably shave a lot of time by not doing it, but I've always had much better success overall doing it that way.

[Steve Schoene]

Nothing at all wrong with that approach. I just haven't found the risk of mishap has been worth the extra time for me, but that's strictly a personal choice.