Applying shellac smoothly without a sprayer

Question

How can I apply a smooth coat of dewaxed shellac without a sprayer?

Whether I use a brush, sponge, or rag, I always end up with tiny raised beads of shellac at the borders of my previous brush stroke. This mostly happens between dips into the can. Trying to fade them down with brush strokes makes it worse.

What am I doing wrong and how can I avoid this?

It's difficult to sand when it dries and in all my sanding attempts I still end up reducing the beads to smooth but visible rough lines. I can cover with another coat but then I am back to square one.

It's obvious that it shouldn't be overbrushed, it even says that on the can. It tacks up so quickly that I have problems just keeping it smooth across brush strokes. I have tried thin coats, thick coats, fading the brush strokes, slopping it on and hoping it levels, waiting a bit and trying to buff it, quick second coat while still wet, all with poor results. I even tried just dumping it out of the can and quickly spreading it around (which sort of solved the problem but made some messy new problems...).

I have a good bit of experience with paint and everything in my bag of tricks is failing me.

The effect is much less pronounced for the first coat on a soft unfinished material, because it soaks in quickly, esp. things like poplar and MDF. But for the most part it always happens no matter where the coat is.

Answer 1

This mostly happens between dips into the can.

There's your problem right there. Actually there are three problems here: working directly from the can, the cut and the brush.

Ideally you don't apply any finish by dipping the applicator into the original container. Yes it is extremely commonly done, but it's still bad practice. This is just about OK for waterbased paints, just about, I wouldn't recommend it literally for anything else. It's an especially poor idea for any fast-drying finish, particularly those with a fast-evaporating solvent like shellac has — at the end of a long working session what is in the can is not the same as when you started, it is now more concentrated.

Secondly, just because shellac comes in a can readymade doesn't mean that's the ideal dilution to apply (same thing with varnish, which is regularly diluted to make it more user-friendly). In fact pre-mixed shellac can be quite a strong 'cut', the traditional term for the dilution rates of shellac, and it can benefit greatly in being diluted to a less-concentrated version for application, a 'lighter cut'. I don't know how universal this is but some common tinned shellacs are sold as a 3lb cut (very strong), and it's frequently preferred to apply it as a 1lb cut, requiring that you thin the commercial product quite significantly which obviously can't or shouldn't be done in the original container.

Thirdly, shellac can be applied by brush and for certain jobs this is the right way to apply it. But it's not the ideal application tool for shellac when tackling large, flat surfaces. Shellac is the classic finish for being applied by a traditional method, commonly known today as French polishing. Now this is one of those OCD/I-have-way-too-much-time-on-my-hands techniques, but it was developed to give stellar results and it still can. It's just loads of work. Doing this full-on is not something for the faint at heart, a proper French polishing job requires hours of effort over at least a few days; the results are considered worth it by some, but to be clear I am not recommending it because shellac is no longer the only way to get that sort of look. Which leads me to...

Why use shellac in the first place?

In a way shellac is now obsolete. What it was relied upon for historically is no longer the case — it was the best finish available for fine furniture then, that's no longer true. If the finishers of the early 19th century had had access to sprayguns and lacquer that's what they would have used and that is what would now be considered "the most beautiful finish in the world" by traditionalists and connoisseurs, not shellac.

I'm not anti-shellac, I like it myself and use it regularly where I value its fast drying time. But it can be a troublesome finish to work with (other readers see this previous Question on issues related to shellac and humidity), it is tricky to apply to a high standard on larger pieces, but perhaps most importantly it provides relatively poor protection to furniture:

• it is hard, but a little too hard (it is brittle);
• it is very prone to damage from water (you get clouding, and note it can be almost instantaneous);
• and of course any alcoholic beverage will soften or dissolve the finish depending on the strength of the drink, leaving visible ripples or raised rings in the finish once it dries.

None of those are issues with even an inexpensive varnish as available in any hardware store! These are scratch-resistant but not brittle, almost totally waterproof and alcohol doesn't bother them. And varnish is far easier to apply to a high standard, in large part because of the relatively slow drying time.

So, my advice would be to use shellac for jobs where it is a useful part of a finishing regimen (e.g. acting as an intermediate coat between dissimilar finishes, as sanding sealer), or when used alone primarily for smaller jobs where its very fast drying time isn't so hard to deal with. This is one reason shellac is still an excellent choice of finish for woodturners and it's why I use it as a final finish on tool handles where I want a glossy finish, such as the handles on these files I restored:

Answer 2

I am starting to become very fond of padding on finishes, using a handfull of cotton balls wrapped in a nylon sock. It carries a lot of finish and applies it smoothly. Thin layers, but that means they dry faster, so it works well. And almost no brushmarks or bubbles.

I've also seen the "pads" sold for paint edging used for clear finishes. Thease sre foam, but have a fuzzy fiber (microfiber?) surface. Again they hold a fair amount of finish and distribute it evenly, without brushmarks recognizable as such.

As another answer pointed out, sanding is debatable....

Answer 3

So after continuing to struggle with this, I found some good advice in a forum thread on the topic in this great post by user Steve Schoene:

On 05-19-2007 Steve Schoene writes:

The problem often is trying to think of shellac as if it were varnish. It's easy to apply, but requires a different technique and mind set. With varnish you flow it on, and even it out--the process is one of smooth and easy.

With shellac, unless you spray, you can't just put on an even spread, you have to make shellac's particular characteristics--quick drying and complete fusing between "coats", and fairly easy sanding work for you, not against.

First don't try too heavy a coating with 1 1/2 to 2 lb. "cut" being the most user friendly. You can use a pad, which is made with a fine weave fabric such as white cotton percale sheeting, wrapped around a bundle of anything absorbant. The pad should be about egg size and have no wrinkles on the surface. (This is similar to French polishing pads, but no oil is needed, nor any particular skill.) You just apply shellac with the pad, working quickly and never going back over an area to fix a missed spot or overlap. You want to apply thin and fairly even coats, but don't obsess over it. Just fully damp, not flowing coats.

You can build a finish a little faster with a brush. I strongly prefer watercolor wash brushes (about 1 1/2" wide is enough for anything). The best bristles are Golden Taklon which are very fine and leave zero brush strokes. The brush doesn't hold a lot, so you never get really heavy coats. Again, you work very quickly, ignoring misses or overlaps. Just try not to miss the same place or overlap in the same place on subsequent coats. These little misses and laps will even out in the end.

You can apply a number of coats 3 or 4 for example, and then let it dry more thoroughly and lightly sand to level out the surface. Then apply a few more "coats" and level again with sand paper as you need to. (You do not need to sand between coats for adhesion, only to level out problems.)

Never let either pad or brush drag. If you notice any dragginess STOP immediately and let the surface dry more thoroughly before proceeding with another coat. If you ignore this you risk getting a "rumpled" mess. (It will sand out after drying overnight, but it's not pleasant.)

When you have built to the thickness you desire, you can level with a fairly fine grit 600 and then 1000 or 1200 and proceed to either pumice (for satin sheen) or to rottenstone (for gloss). Rubbing compounds also work well. You should give at least several days or a week before rubbing out--not nearly the month you should wait before rubbing out varnish.

In particular, the tip I learned the most from there is to never go back and fix missed spots; just let the next coat cover them, taking advantage of shellac's good fusing of coats. It also hits on some of the things mentioned in both the other answers currently here (the uniqueness of shellac and the use of pads).

Following the advice in the post above left me with a much nicer finish on the last piece I put shellac on.

Also, of some use here, here is a nice table of dilution ratios for diluting premixed shellac:

Answer 4

i’m reading about another method, which consists of building up the finish with a brush, and then do something different for the last coat to even out the finish.

For the last coat, you’d make a mixture of 75% shellac and 25% mineral oil, and apply with a pad. I’m paraphrasing from this popular woodworking article. the oil allows the pad to glide easier, and you don’t have to rush as much.

At the end, you’d remove the oil (which will float to the top) using naphta.

As far as answering why brush strokes are there in the first place, i can’t be of much assistance — i’m trying to figure it out too.