Varnish and lacquer

[Larry Jaques]

#5 IS ALIVE!

-- A sound mind in a sound body is a short but full description of a happy state in this world. -- John Locke

[Phil Endecott]

I've spent the last week waiting for a can of spray lacquer to arrive

- somehow I managed to choose a very slow supplier...

I've now tried it on a small test piece, and I've put a photo here:

is after very very many "thin coats". Maybe my idea of "thin" is too thin; they were thin enough that the solvent had evaporated and it seemed dry in under a minute. Even after all these coats, as you can see there are still many "dimples" over the pores in the grain. I have the impression that if I put on some thicker coats it would smooth over those holes, but that might have some adverse effects.

I am now wondering if "sanding sealer", or some other product, is needed first to block up these pores first.

Or alternatively, some sort of wax or oil could do the same job. I considered applying some sort of oil first but my feeling was that I was happy with the natural colour. Oil might improve the colours, or I might regret using it. (My local store seems to have lots of Danish Oil, but I don't think I saw any Tung Oil.)

Or perhaps I am supposed to sand it to remove these dimples before applying more coats?

Any thoughts?

Phil.

[SonomaProducts.com]

Oh Phil...

Thick or thin, you won't have much success filling grain with film finishes. You need to learn about grain fillers if you want to have a piano smooth finish. Semantics really. You did get a really glossy finish but you wanted a very flat (physically flat not visually) glossy finish.

Get some expert advice from the master. Look at the bottom of the page.

[Richard]

I won't claim to be an expert, but I've done quite a bit of varnish and lacquer on my sailboat.

For that smooth as bone china look, you have to fill the wood grain.

What I do is apply 3 or 4 coats, then sand the finish smooth - or as smooth as it can get at that stage.

Let the finish dry really well between cycles.

Try not to sand all the way back to the wood surface.

Repeat until satisfied with the finish, or bored to tears.

[Larry Jaques]

Any and all of the above. Lacquer is usually used on the flat, fully sanded wood for an impeccable gloss finish.

Varnish is thicker and usually hides grain plus providing a fairly glossy surface. It would be your easiest, 1-step finish.

Oil finishes leave the grain, which is why I like and use them almost exclusively. You can still feel the wood. Waterlox (my fave finish) can be brushed on heavily, but you lose the tactile feel, the "hand" of the wood, when the finish is built up like that. I hand rub 3-7 coats of that onto my projects using the satin, and I usually wax it with 0000 steel wool to flatten it a bit more. YMMV. The grain is still visible and feelable on a hand-rubbed piece.

To continue using your lacquer for the glossy finish, yes, try a sanding sealer. Find a compatible finish. It will build up and flatten the surface for a glossy surface free of divots. Spray the sealer, let dry, sand. Repeat until the surface is completely smooth. Then lacquer it for the seemless gloss.

-- Live in the sunshine, swim the sea, drink the wild air? -- Ralph Waldo Emerson

[Lew Hodgett]

-------------------------------- Enough to get into trouble.

-------------------------------- I've found this page, which seems to be comprehensive:

Any thoughts?

-------------------------------------- S3 makes GOOD stuff.

Have used at least 10,000 lbs of the stuff.

Epoxy contains NO UV inhibitors, thus you need to top coat it with an outdoor poly. (Epifanes is the gold standard).

Before venturing down this road, make sure the investment of time and money is worth it.

Have fun.

Lew

[Phil Endecott]

paste wood filler" described there (called "natural grain filler") and indeed it is an opaque light (pine) colour, which is very visible when I try it on this wood. I've not yet found a source for anything like the "transparent grain filler" described there. What is "sanding sealer"? Will it do what I want?

[dadiOH]

Why didn't you just go to Lowes/Home Depot/Ace and buy a can? __________________________

With lacquer, you don't necessarily want "thin", you want "even". Once laquer dries, the remaining material is very thin; when I brush on lacquer, I put on as much as possible without having it run off the edges; that not only gives me a thicker coat once dry but lets the lacquer "flow" (even out). __________________________

See below __________________

Lacquer may eat oil; that is, cause it to reticulate.

You won't likely find tung oil in a local store. What you will find are "tung oil finishes". Those are mostly BLO with a dollap of tung. Maybe a dollap of varnish too. The manufacturers put out a world of misinformation about finshes, all claiming superiority and/or proprietary miracles. The fact is, there isn't a RCH difference among them...they all start with the same palette of available materials.

BLO and tung are both useful but they are different; BLO will ultimately become quite dark; how dark depends upon how much was absorbed and/or trapped in the wood pores. By "quite dark" I mean almost black, albeit a reddish one. If you want to see how dark, look at a can that has some accumulated on it over a few months from pouring.

Another difference is that BLO will support the growth of mold better than tung. IMO, YMMV _____________________

Yes. If it has dried for at least a week and has no odor, sand until there is no shiny spot anywhere then respray 2-3 medium coats. Those too may require sanding...what you want - a flawless, glossy surface - is very hard to accomplish without rubbing out the final surface with ever finer abrasives.

The dimples are from the grain in the wood. A magnified cross section of a piece of wood would look like the basin & range area in Nevada...there would be towering peaks and deep valleys. For a piece of wood to have a flawless finish, the valleys have to be filled up. You can fill them with paste wood filler, sanding sealer or the top coat material itself.

The first two are just small, solid, more or less clear particles with a bit of something to stick the particles together after the something dries. The particles can be most anything that fits the criteria of what you need; for clear, pumice or other fine silica is usual. The "something" to stick them together can be lacquer (nitro/vinyl/acrylic), varnish (phenolic/alkyd/poly/Damar/etc), shellac, BLO, etc...anything that will sand easily and be compatible with the final top coat. You could even use starch - drying type drywall compound is nothing more than very fine calcium carbonate (same as limestone) and starch.

The reason to use the either of the first two is time: being largely solid particles, they will fill up the valleys faster than a plain top coat. In order to get a totally smooth top coat surface the underlying surface has to be perfectly smooth to begin with. Or be made so.

The reason things need to be totally dry is this: when you fill up the valleys, they contain much more material than what covers the mountain tops; consequently, they take much longer to dry. If you sand before they are, they will continue to dry and you'll wind up with valleys again; however, they will be less deep than they originally were.

If you had a way to spray laquer thinner, I would suggest you spray your piece with it and immediately place it in a small, closed box to retard drying. Once dry, it should be considerably improved and require less sanding before the final coats. You could do something similar by spraying a heavy, wet coat of lacquer but that would be less effective.

[Phil Endecott]

None of those stores exist in the country where I live.

Often I find it quicker (and maybe cheaper) to order something online and have it arrive the next day rather than visiting the two or three local stores, but this time was an exception.

Thanks for all the suggestions.

As I mentioned before I have got some "natural" grain filler, and this seems to have done its job; I'm going to try spraying some lacquer over that later. But it's not acceptable for the real item because of its colour, so I'll need to find a transparent alternative.

Cheers, Phil.

[Richard]

The grain on your sample was pretty extreme.

I ran into the same kind of thing with 20 year old wood in my boat. The grain had raised quite a bit.

My solution was just layer after layer of varnish. Let it dry hard after 4 or so layers then sand it out a bit more.

I use clear varnish only for buildup coats, and a final couple of coats of satin.

I think it came out pretty nice!

[ed_h]

Phil--

I wish I'd seen your post sooner. I think I understand what you want, and I do it fairly often on various woods. I use multiple coats of lacquer--sometimes ten or twelve. I use a traditional method that doesn't use a sealer or filler, but requires sanding between at least every two or three coats.The sanding is to level the surface by removing the higher spots. Don't worry about getting it perfectly flat on the first sanding or two--there will still be some grain telegraphing through. By the time you are on the last two or three coats, the surface should be flat with no evidence of grain texture. Be very careful when sanding near edges or corners as it is easy to break through.