Shellac and Varnish

[Darius Ferlas]

A couple of question to the finishing gurus of the forum:

I'm a couple weeks away from finishing a walnut dining table top.
At this point the simple finishing schedule I'm planning to follow is:

1. - Zinsser orange shellac (NOT dewaxed, except for the home method - cooling down and then pouring through a coffee filter)
2. - Pratt & Lambert #38 gloss (2 coats)
3. - Pratt & Lambert #38 dull (2 coats)

P&L #38 not being a poly, my understanding is there should be no problem with adhesion of #38 to the shellac. Is that correct?

Also, #38 tech data warns against standing water over the finished varnish. I'm not sure if I understand that properly and if #38 is in fact suitable as a top coat for a dining table.

[Joe Chritz]

I wouldn't jump anywhere near the guru level but here is my take anyway.

You should be fine with any non-poly oil base varnish over any shellac. I assume the shellac is for color since it really won't offer any other benefits under a quality varnish.

P&L 38 is a quality varnish and should perform as well as any of the others. Standing water is always a bad idea for finishes unless you use some super finish like epoxy, etc. Unless you plan on leaving puddles of water on your table it will be fine.

Joe

[Prashun Patel]

I'm no guru, but I will say with confidence that your finishing choice is a good one. P&L varnish is well-respected and a very appropriate choice for a dining room table.

Just beware that walnut is open grained. So, if you want a glass smooth surface, you might require more coats of varnish. Or you might consider partially filling the grain with shellac by brushing on a couple coats, and sanding them back to the pores. Not SO critical on a satin surface, though.

[Neal Clayton]

poly varnishes have more adhesion problems than other varnishes, but that doesn't mean that others lack trouble with sticking to waxy shellac. i would avoid using waxed shellac if anything is to go on top of it that isn't wax or more shellac.

you could always put a barrier coat of clear on top of your shellac color coat to ensure that there aren't any adhesion problems. might not be necessary, but is easier than removing varnish that doesn't stick .

[David Thompson 27577]

I'm with Neal -- add a coat of dewaxed super-blonde shellac before the varnish.

It's a good barrier to keep the wax from the first coat from causing problems.

[Tom McMahon]

Go to www.shellac.net there's lot of good info on shellac and how to use it . No affiliation.

[Brian Hinther]

No expert here either, but be aware that the flatting agent in dull varnish may cut down on the transparency of the finish. For that reason you might want to limit it to just one final coat.

[Henry Ambrose]

I'd skip the shellac, sand in a filler coat of varnish, then enough coats of gloss to get the finish looking complete, ending with one coat of dull. If you've not used this finish before it might be difficult to predict how many coats it will take.

[Scott Holmes]

Adding a coat of de-waxed shellac over shellac that still has wax will NOT seal in the wax.

The de-waxed shellac will dissolve some of the previous coat and you will still have some wax at the surface.

I'm with Henry, skip the shellac; use the gloss varnish to fill the grain.

[Prashun Patel]

He might be using the shellac to warm the color of the wood.

Darius, the beauty and danger in posting on this forum is that you'll get a million different opinions, which after a while can confuse you.

I believe your original schedule is just fine: waxy shellac, and 2-coats of satin, and all.

[Howard Acheson]

You do not need to filter the shellac at all. It removes only a small amount of the wax but even the full amount of wax is not a problem with non-poly varnish.

Other than that, you plan should result in a nice finish. I would suggest thinning the first coat of the P&L about 25% and then thin the subsequent coats about 10% with mineral spirits.

As always, test your whole finishing schedule on scrap before committing to starting your finish.

[Darius Ferlas]

Thank you for all the responses.

I decided to use orange shellac for color. I saw it in action on walnut and I liked the tone it gave. P&L #38 alone doesn't seem to be able to give me the same tone.

I actually called around to make sure things will work out before I ruin a pretty decent glue-up. The Zinsser tech support wasn't aware of P&L product properties and compatibility but he insisted that Zinsser SealCoat will definitely provide very good adhesion of pretty much any clear coat.

Getting the dewaxed flakes is an option but two issue with that remain:

- finishing being my least favorite aspect of woodworking
- I can't get it locally and the shipping charges jack up the cost significantly

I have found a local distributor of Zinnsser product and they always have pretty fresh shellac in stock.

So now my schedule is somewhat modified:

- orange shellac 1 - coat
- SealCoat - 1 coat
- P&L #38 gloss 3 coats
- P&L #38 satin 1 coat

I am still wondering whether there is a benefit of filling the walnut pore with shellac rather than with varnish?

[Prashun Patel]

I assume u mean 1 coat satin as the last step. If you want a filled pore surface, then you'll have to keep adding gloss varnish coats until the pores are filled, then do yr final satin coat.

The only benefit to filling with shellac is that it dries fast. So you can brush it on, sand it back, brush it on, sand it back a couple times in a day. With the varnish, you'll have to brush it on, wait a day, etc.

[Joe Chritz]

I still don't think the sealcoat is required but I can tell you that I use a lot of it and it has always performed excellent. It is my standard first coat for just about everything that gets EM6000 for a finish.

It adds just enough warmth to kill off the bland that waterbase sometimes gives.

Joe

[Jim Becker]

P&L #38 will adhere fine over the Orange shellac, but there is no harm in using a barrier coat of Sealcoat over the Orange shellac "just to be sure".

I agree with using the shellac on the walnut, BTW, to warm the color, especially if it's kiln dried walnut as much of that is also steamed to increase yields. (steaming darkens the sapwood, but it leaves the walnut a muddy brown color with little life in many cases) I actually like using shellac on the air dried walnut that I work with as it enhances the wonderful golden brown color that walnut will age to over time.