Shellac then polyurethane

[Jim Riseborough]

Got a big pine table top, was going to put a shellac on first, then sand, then a few coats of Varathane poly. Any indications this is not a good idea? Will use zinsser shellac.

Thanks
Jim

[glenn bradley]

There is always the first question; why use the shellac at all? I will assume the pine is irregular or pitchy? Maybe it has rustic coloration that you do not want to telegraph through your topcoat? If you decide to use the shellac I would use Zinsser Seal Coat which is dewaxed. I often seal things with a very thin application of Seal Coat and follow with a 1:1:1 blend which includes a modified phenolic urethane. I sometimes use this on end grain and not on the rest of the piece to unify the coloration from the oils. I have pieces going on 20 years old that still look great. Your oils will not penetrate as much as on bare wood so I would strongly recommend a test board.

[Jim Riseborough]

The wood is very stable and dry, not pitchy at all. Was thinking it would be a good ‘sanding sealer’.

I will try a test piece to be sure of what I’m doing.

[Phil Mueller]

Jim, I think you are on the right track. Pine can be blotchy and the Seal Coat should help reduce that. Test board is best...but even a smallish test board may not indicate all the blotch you might get on the entire table top. I think you’ll be happier with the Seal Coat first results. And besides all that, it doesn’t hurt one bit.

[andy bessette]

...was going to put a shellac on first, then sand, then a few coats of Varathane poly...

That is called a science project.

If you are serious about getting a long lasting finish, don't experiment. Begin instead with tried and true methods that have worked for professionals forever. For example, follow the formulator's instructions.

[Jim Becker]

You must use wax free shellac for this application, but it's a very common method. Zinsser SealCoat is wax free if you want pre-mixed but making from flakes gives you more color flexibility.

[glenn bradley]

The wood is very stable and dry, not pitchy at all. Was thinking it would be a good ‘sanding sealer’.

I will try a test piece to be sure of what I’m doing.

I will add that unless there is a compelling reason to add something to your finishing protocol, I would not. Using dewaxed shellac as a sealer to help with blotch control is a compelling reason. Using the shellac as a vehicle for a dye to tint the piece is also legit IMHO. I am not big on colorations so I use this method when I want a bit of toner but, not a full-on dye job.

[Larry Frank]

I use shellac under poly a lot. Typically, I sand the shellac lightly and then multiple coats of wipe on poly.

[Jim Riseborough]

Been working on the table and finishing it, I have the top with 2 coats of poly. I have been thinning it, and it seems to help get even coverage.

For the final coats, how do you guys feel about wiping it on? I think I would get better even coverage, and no thick or thin spots.

Thoughts?

[roger wiegand]

Shellac under varnish finishes is about as "tried and true" as anything in finishing ever is ;-), and used universally by every pro finisher I've ever spoken to. I do it all the time, almost reflexively.

With varnish (including polyurethane varnishes) I get a more even coat with a brush than I do with wipe on, but that may just represent way more practice with one method over the other. Wipe on is fine when I want to leave an extremely thin coating and can wipe off virtually all of the finish applied-- of course then it doesn't matter whether it was originally applied with a brush or with a rag.

[Prashun Patel]

"blotch" is usually not objectionable to me. If I were you, I'd make my own sanding sealer by thinning your varathane poly 25-50% with mineral spirits to make a wiping varnish.

Your test board will be the BOTTOM of your table.

Flood on the first coat with a foam brush.
Knock down any nibs with some high grit sandpaper (+320).

Then keep applying subsequent coats with a shop towel. You can look up techniques for applying wiping varnish. While it takes more time to apply a thinned finish this way, it can lead to less headache because each coat is easier to apply and control than a brushed coat.

IIRC, Varathane is pretty thick; it's intended for floors, i think.

[Mike Null]

I built a kitchen table 25 years ago and finished it with Minwax Polyurethane. I used Minwax golden oak stain first. It has served us very well though it has needed refinishing for a couple of years. I'm going to do that this month and will follow the same process. I brushed the table but for the chairs (everything was red oak) I wiped on 5 coats of poly. They just need waxing--they've worn well.

My kitchen cabinets, also red oak, are in need of some re-finishing including touch up with stain in places. I'm going to wipe on poly for this and I may use some shellac to get a good color match if needed. I keep zinser Sealcoat on hand.

[Jim Becker]

Mike, for your kitchen refurbish, don't forget you need to do a substantial amount of "serious" cleaning with TSP, etc., to fully insure that any oils and grease are removed before you move on to the actual finishing process. It's really critical in a kitchen environment to do this.

[Mike Null]

Jim
Thank you for that! I hadn't considered it but now will make another trip to HD. The cabinets should really be replaced but I just spent a small fortune on a total bathroom remodeling and the $well$ is dry.

[Jim Becker]

Refinishing/refurbishing existing cabinets can be very cost effective if they are physically sound. You can just restore the finish to be the same, change the finish, change the doors/drawer fronts/hardware, whatever, to get a nice fresh look if you want, too, for substantially less coin than a full replacement remodel. The cleaning thing is just because of the nature of it being a kitchen...you have cooking grease/oils quite obviously and they spread much farther than just near the range as well as finger/hand grease and oils just from regularly operating the doors and drawers.