Woodworking Finishing Question
b0bd0d
Registered User regular
Registered User regular
I'm working on a little chest of drawers that will contain clothes. It's a basic carcass with 4 drawers. I'm using birdseye maple and purple heart. I'd like to tung oil the front of the drawers and the carcass outside. I'm concerned about using an oil based product on the inside of the carcass and to finish the drawers, as the off gassing of the oil will cause anything put in the drawers to stink. I could just oil the front and leave the inside unfinished but I'm concerned about issues with humidity and having one side of the wood open to the elements. After doing some research and stuff, I'd like to oil the front and back of the drawer front and the outside of the carcass. To seal the inside of carcass and the rest of the drawers with no odor problems, I'm either leaning towards a thin coat of shellac or lacquer.
Anybody have any suggestions? Could I tung oil the front of the drawer front and shellac the other side of the board? Seems kinda iffy and I don't know how I would transition from oil to a clear finish. Oil both sides and shellac the face facing into the drawer to help not stink?
Anybody have any suggestions? Could I tung oil the front of the drawer front and shellac the other side of the board? Seems kinda iffy and I don't know how I would transition from oil to a clear finish. Oil both sides and shellac the face facing into the drawer to help not stink?
b0bd0d on
0
Posts
Are you using 100% natural tung oil, or something different? Personally, I like to use polymerized boiled linseed oil for my projects, as it gives the same effect (popping the grain), though BLO does leave a slight amber tint to the finish. I've yet to complete a set of drawers, though I have completed a couple of vanities using Tried and True Original Wood finish and don't really notice a lingering residue/scent (it dries significantly quicker than 100% natural oils).
One thing I might try would be Minwax Wipe-On Poly, which is just a polyurethane finish that's hand rubbed.
The folks over on the WoodNet forums are awfully friendly and might provide some better insight.
If you want to do tung oil though, why not do it all in Tung oil?
Finishing the two sides in different styles of finish(like oil and shellac or lacquer) is not optimal but probably won't be a problem, especially if the inside coat is thin. If you live in an area with great changes in humidity I would try to get the finishes a match, otherwise I would just see what happens.
If you are using 100% pure tung oil you will have a scent in an enclosed area for months until it completely cures, if you use 'tung oil finish' (which may or may not contain any actual tung oil) it will usually cure in a few days(or hours) and be fine to put your clothes in.
It's been a long time since I built anything, but I seem to recall a good coat of poly wax sealing off any problems with oil finishes.
You definitely can use the wipe on poly on top of the tung oil for a combination effect (bottom tung oil will pop the grain, etc). The problem arises in how long natural tung oil takes to cure, and having to wait that long before you're supposed to apply the poly finish on top.
You would be fine shellacing the inside and finishing the outside with an oil. I don't like linseed oil for anything that isn't in a rustic style. It's just not enough of a finish and like Oletta said it will leave a slight yellow tint that will deepen with age. This is true of most oils though the aging with tung oil doesn't have much of a tint to it. It's more of a overall darkening. Traditional dressers left the inside of the drawers unfinished. Unless you are dealing with a large surface area unmatched finishes will not be a problem. If you want to leave the inside unfinished then go right ahead.
The finish you choose really depends on just two things.
1. Your skills and equipment
2. The style of the piece
Since you used birds-eye maple and purple heart I imagine this is a "fine" woodworking piece.
If it's done in a classic style such as Queen-Anne or Sheraton then go with a lacquer (or water based poly if you prefer) finish. If it's a modern piece, something with clean simple or possibly bold lines then why not continue the style into the finish by either adding a painted accent (like painting the area around a keyhole on a locked drawer) or painting a stripe along the top of the molding.
If you decide to use tung oil then surface preparation is key.
Sand the displayed faces of the piece (usually top sides and front) to 250 grit. Then take a non-linting cloth and wet it with warm water. Wet the entire piece with the cloth. Don't skimp on the water. You want the surface to clearly be wet but without any puddles.
Wait 10-15 minutes for the piece to dry. You should notice that the surface feels rough. The purpose of wetting the wood is to raise the grain of the wood. During planing and building of the piece the grain gets compressed. wetting it allows the grain to rise up. Sand it back down with 400 grit so it won't rise when you apply the oil.
For the top, I like to use a 600 grit. This will make it really shine.
I also like to apply the first coat of tung oil diluted 50/50 with a solvent (you can use mineral spirits turpentine or citrus solvent)
Of course if you're using mechanical rails then it doesn't matter.
I won't say it's a "fine" piece. I've read books and magazines, I have about 20 years of woodworking learning before I can make a piece I'd consider fine. I'm actually a mining engineering student, woodworking is just my student job. The shop is open to anybody to work in and I help people make stuff, use tools correctly/safely, etc. Basically, they're paying me to teach myself woodworking while teaching other people. It's really screwing me up because now I'm developing artist/creative talents but have no knowledge of anything. I don't wanna engineer anymore, I just wanna make stuff.
The design is fairly simple with clean lines. I found a 13" x 32" piece of purple heart with some pretty neat grain, so I cut that into 4 clean pieces for the drawer front and used maple to make the drawers. I think the drawer pulls will be a simple line of maple, maybe something darker(ebony? We got some brazilian rosewood?), so that attention will not be drawn from the grain. The carcass is purple heart and birdseye maple.
I'm not sure if I'm actually going to sand it before finishing. I started using 100 and 150 grit to clean it up a little bit but then started using a piece of glass as a scrapper. I....I don't know how to sharpen a metal cabinet scrapper but I can cut perfect squares of glass. It seems to give a much better feel than using sandpaper. Smoother almost with less work. I really like the feel of it but this is the first time I've used a scrapper and not sandpaper. Not too familiar with it and how it will affect the finish. Should I sand it anyway? I'll experiment when I go to work today and see how much the grain is raised using water on some of the pieces I've scrapped.
I'm wanting to use Formby's Tung Oil Finish, a tung oil/varnish combination. I really like the resulting finish, especially the high gloss version. I've been using #0000 steel wool between coats of oil on other projects, cleaning with blown air from the compressor and tack cloth before a new coat.
The drawers are wood on wood, so I will wax and sand the hell outta the bottoms. Already had a learning experience with that.
Why do you dilute the first coat of tung oil? Are you using the thinned coat as a sealer?
As for whether you should sand or not. Unless your scraping job is spotless, you will get a more consistent finish with sanding. if you have a good scraping job you can still slightly wet the surface and just polish it and knock off the hairs with 420 grit.
If you want the character of the slight variation in the surface that a scraper gives then by all means scrape away and leave the sandpaper in the drawer.
If you want a really high gloss finish you can wait until the surface has completely cured (at least 2 weeks) then buff the surfaces with #0000 steel wool and apply a coat of wax. Apply the wax with the steel wool, wait a minute for the wax to harden and then buff with a fine cloth. If you wait too long (and depending on the type of wax you use) you will have a hard time buffing. Just re-apply the wax to soften it up. Carnauba wax is a relatively hard wax and will allow you to easily repair surface scratches by just applying more. I usually just wax the tops of dressers and the drawer fronts since the high-gloss it gives stands out the most there and usually you use the best figured grain for those parts. It also adds a subtle variation in sheen between the case and the rest of the components.
Remember, the difference between a good piece and a superb one is in the finish.
And the point of scraping is to 'knock off the hairs', so if he properly scraped there should not be any wood fibers visible, unless there was deep tearout. So sanding on top of that would be asinine.
For finishing, I scrape, thoroughly remove surface dirt with cheesecloth then apply my finish. Minwax natural does an excellent job of bringing the grain to the surface, but you're in for a long dry time. I generally apply liquid johnson's paste wax in several coats for a slightly darker finish. It's simple, cheap, and protects the wood very well.
Please don't use shellac, unless you're using it as an umbrella term for other sealants. Shellac is so ugly.
Forbe: blasphemey! french polish is still the gold standard of a high quality finish and is used on some of the finest pieces out there, plus he's just talking about sealing the inside of a drawer with it, not exactly the most visible of locations.
Is there a functional reason for not using the same type of finish on the whole thing? Aside from the 'oil gas'? Seriously, coat it, and let it dry for a week all separately, then apply your top coat of choice. Mixing finishes (as in two different types on the same layers) is a disaster waiting to happen. You may discover reactions between the oils and other polymers that you weren't expecting, especially where the two finishes meet.
If you are super concerned about odor, even after considering a long-term drying period, butcherblock oil leaves a beautiful gloss finish in 2-3 coats over a course of 3 days. It takes roughly 48-72 hours to set up after the final coat, but there is no odor present afterwards. It will make the grain of lighter woods pop out and slightly darken darker woods. I use it almost exclusively on a lot of my finished work.
I prefer scraping because I prefer the fine shavings to sawdust. For easy sharpening, I recommend the Veritas Variable Burnisher.
Also, I seem to be in the exact same position you are - 27 year old engineer, but I'd rather spend all day in my woodshop, hah. Also, if you haven't discovered it yet, Google Sketchup is a wonderful tool to use.
No one was talking about mixing two finishes on the same surface, and I said he should just use the formbys on the inside and outside.
Butcherblock oil is usually mineral oil, which does not cure, it's not good for the inside of a drawer, not sure what finish you mean.
As far as scraping vs sanding, I prefer to scrape and then sand the higher grits with a block, it's hard to get a flat, level surface for me with a scraper, but it's much more enjoyable to scrape than sanding, especially in the lower grits when you're kicking up a lot of dust.
ps I have the veritas burnisher, and I hate it