Bookcase Finishing questions.

[Sean]

Hello, I have a few questions about finishing a bunch of bookcases I am working on. I have made these bookcases with shelves on the front and back. (They are going in my bookstore which is opening next month.) They are 60" tall, 48" wide and 25" deep. (About 12" deep on the front and back.) I am planning on using a clear or mildly tinted stain on inside sides and shelves of these bookcases and painting the back and outside sides black for a contrast. (I am using 3/4" "Radius Pine", a very nice plywood on one side and adequate on the back. The Good side would be used on the inside of the sides, because very few of the outside sides would be visible as the bookcases would be lined up in a row, and I will be finishing the end bookcases a little differently.) I was wanting to use some sort of clear varathane or other protector on top of the stain to protect it. My questions are: - What is a good protector, or should I just use varathane? - My wife saw some exterior-grade deck varathane(?) on sale for a great price by the gallon. What kind of difference is there between the exterior and interior? (My inclination is to stick with interior, hers it to say that if it is exterior it will give more protection.) - Is it a good idea to use the varathane on top of the paint as well to give it more protection? (I don't want the paint to wear off onto the books.) - Please keep in mind that these are bookcases that are going to see a lot of use, and so have to stand up to more handling than most bookcases. (Because they are going to be in a store.) - Any other finishing suggestions would be greatly appreciated. (ie: how many coats of varathane I should use.) :) Thanks, Sean.

[C & S]

First, Varathane is a brand name. They make a several products. I assume that you are asking about oil-based polyurethanes in general.

Oil-based poly is a good protector. However, although it drys to the touch within a day it does not fully cure for at least a week. If you go that route, don't plan on filling shelves immediately.

Shellac would offer a bit less abrasion resistance but far superior dry time (completely cured in a day).

Exterior/Interior is about moisture resistance. It's not an issue for you application, unless you plan on leaving them out in the rain.

No. It would not adhere well and it might look weird. Imagine taking you band new automobile and wrapping it in saran wrap.

**Oversimplified** 3. (Any type of clear finish) The first coat seals, the second coat gives you some build, the third will make the build even.

There are books written on this stuff but a couple general pointers:

1. Fix surface imperfections between coats: sand or scrape off dust nibs or drips after each coat
2. Thin your finish a bit (particularly poly straight froma can) is thick and goopy. You can build up a thick layer really fast like this but any surface imperfections will be correspondingly "thicker". Multiple thin coats will always look better than fewer thick ones. Of course that takes more time

Good luck.

[Jim]

Wait the full week, like C & S said, for the poly to dry & don't use lots of thick coats. Books will go on fine & come off fine if they're there for hours, but after a day or two, they'll stick if the finish isn't cured. Very ugly.

About 10 years ago, I did some remodeling at a plant that packaged paints & supplies locally. IOW, they'd get tankers & 55 gallon drums full of product & put it in the pint/quart/gallon cans you see on the store shelves. I watched them do that one day with exterior & gloss interior poly - both came out of the same drum, but went into different containers. I asked the owner to make sure it wasn't a mistake. It wasn't. I don't know if that is still the case today, but at that time, there was about $1/quart difference between gloss interior & exterior poly, as I recall. The latter cost more.

According to the owner of the plant, those were his instructions from the manufacturer & it was legal. He said the microscopic bubbles that form in the satin poly finish made it impossible for any satin poly to really be exterior & that all gloss poly was. Not sure I believe him completely, but it was an interesting glimpse into the marketing behind finishes. I've always found the entire subject pretty confusing. I think the last issue of Popular Woodworking had an interesting article on finishes, classifying them.

Jim

[DanG]

I am not a strong believer in water based things in general.

Well now, wait a minute. I am thinking this statement through. I like latex wall paint. I don't believe in latex enamel. I like emulsified tar. I really like water based polyurethane. I think it may be a better product than the oil based.

(top posted for your convenience) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[Hax Planx]

You will want to use a wipe on polyurethane to cut down on labor. Brushing anything besides paint would just be impractical and brushing polyurethane or any other varnish takes some practice to avoid making a mess. A nice thick finish would be nice, but I don't think you have that luxury unless you want to put in weeks of labor. Wipe on as many coats of poly as you can stand and buff lightly with steel wool between coats. You could use the deck poly and thin it down to wiping consistency, but outdoor varnishes are designed to be soft and flexible and consequently not as tough as indoor varnishes. Good luck, I don't envy you that finishing job.