I am staining interior doors made of fir. The doors were pretty smooth unfinished straight from the manufacturer but feel gritty after I applied the stain.
I intend to apply waterlox varnish after staining as the topcoat. I ultimately want the doors to have a nice furniture-smooth surface.
I would appreciate any advice on how to achieve this. Should I do a light sanding after staining? Is rubbing out a better approach? I’ve never rubbed out any finish – I’m new to this – so any advice people have is appreciated.
Thanks!
Replies
I suspect that you used a water-based stain, and what happened is that wetting the wood with the stain caused the fibers to swell, resulting in what is known as "raised grain." You can give the wood a very light sanding (I'd use 220 grit), but it's possible that you'll remove too much of the color that way. If that happens, you can re-stain, but you might want to dilute the stain in order to avoid applying too much color. Experiment on a test piece first!
The normal procedure when using water-based finishing products is to first dampen the wood with plain water to raise the grain, then sand, then apply the finishing product. By sanding off the raised grain before finishing, any additional raising of the grain caused by the finish will be greatly reduced.
When sanding to remove raised grain, use a very light touch. If you sand too much, you'll remove more than just the raised grain, which will defeat the purpose by exposing new fibers.
-Steve
I actually did not use a water-based stain. I used Zinser shellac mixed with dye. I first applied a "washcoat" of shellac (diluting it with denatured alcohol to achieve a 1# cut) to seal the wood to avoid getting a blotchy finish. Then, I went over that with a regular cut of shellac mixed with Transtint dye.It sounds like from the posts I need to attempt a very light sanding using 220 grit after my initial stain application and then apply a second coat of stain as necessary before heading on to the varnish.Thanks for the advice.Joel
Shellac raises grain, too (not quite as much as plain water), so that is indeed what happened. As it now stands, it may be difficult to flatten the raised grain without significantly affecting the color.
-Steve
Joel,
I used Zinser shellac mixed with dye
Was it dewaxed, i.e. Zinsser Seal Coat?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Bob,
I do not believe it was dewaxed (I am not home right now to check). The product is simply called Zinsser Bullseye Shellac, Traditional Finish and Sealer.
What impact would dewaxed have over regular?
Joel
Joel,
My understanding from previous posts in Knots is that non-dewaxed shellac can cause adhesion problems with some topcoats. Also I'm wondering if waxed shellac might cause issues with what I call skim sanding? Removing the nibs.
Hopefully some of the finishing gurus can clarify this for us.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
The wax actually makes sanding easier. And it shouldn't be a problem with Waterlox as the top coat; it's mostly an issue with polyurethanes and waterborne finishes.
-Steve
The 3-M Grey or is it Gray? PADS WORK WONDERS!
I think Steve Schafer is likely to have it right about the grain raising.. Personally, I think the best time to sand off this "nubbiness", is after your first sealing coat of your finish. That will have stiffened the fibers and made them easier to cut off with sandpaper. This also decreases the risk of cutting through the stain.
But. still if you do cut through patching the stain isn't a fun task, so a very light touch on that sanding will be in order. I use 320 grit for such jobs.
Your initial coats of varnish will want to sink in differently on early vs. late wood which are particularly different in terms of density with fir. For a really smooth finish you will have to sand those stripes level after a couple of coats of the Waterlox.
Edited 5/7/2008 7:12 am ET by SteveSchoene
fausonj,
You have asked several different questions in one and you're a little confused regarding initial finishing techniques such as leveling raised grain and rubbing out which is the final treatment of the surface of a fully-cured "thick film" (multi applications) finish.
You want to know how to achieve a glass-like finish but then also about a "nice furniture-smooth" surface.
I interpret the latter to be "uniformly even and smooth to the touch" but not glass-like. Actually, such a surface is first necessary in order to progress to a glass-like finish.
First, you must remove the raised grain, prior to applying any finish, as already described in the previous posts. Assuming you properly surface sanded before staining, ending with 150 to about 220 grit. Remove raised grain with 220-320 grit on a sanding block. Re-stain if necessary. Very little raised grain should occur with a second application, but carefully take that down also.
The next step is up to you - apply a sanding sealer. A coat of 2# cut shellac is excellent for this. Use dewaxed if you will be finishing with polyurethane varnish or other synthetics. Regular (wax-containing) shellac is ok under oil-based varnish. Then gently level-sand the sealer (220-320 on a block) to a uniform, smooth condition.
Then apply the top coat. If you did not use a sealer, dilute the first top coat with an equal amount of solvent. When dry, carefully scuff/level sand (220-320 on a sanding block). Then apply 2-3 full-strength coats, leveling each to remove dust, nibs, and any brush marks when completely dry.
Let the final coat completely cure for at least a week and preferably a month with varnish. Then comes "rubbing out." Level sand with 320, 400, 600 on a block then use 4-0 steel wool. That will result in a perfectly smooth, bright satin glow "furniture finish." Following that with automotive polishing compound (white) will give a dullish glass-like furniture finish. Then automotive "swirl remover" (I like Meguiar's Scratch X) will give a perfectly clear, "mirror-like" surface.
Rich
Rich,
Thanks for the tips. I can tell there is a lot of expert advice here!
Yes, I am a little confused as I am a novice at this. What I am really going for is an even "furniture-smooth" finish - not necessarily a glossy, glass-like, or "mirror" finish. The project is interior doors for my house and I've used a mahogany shellac-dye stain using regular Zinsser clear shellac with the intent of giving the wood a rich color that I can then apply a topcoat of varnish over.
One question I wanted to ask you is the merits of the sanding sealer step using 2# shellac. I am certainly open to doing this but was simply wondering what the benefit is if I will be going over the project with 2-3 coats of waterlox anyway.
Could you elaborate on the merits of the 2# shellac sanding sealer coat?
Also, I've learned that a light sanding and reapplying a second coat of stain is going to be a necessary step. I sprayed the stain on two of the doors yesterday and allowed them to dry when I went in to work. Last night when I got home, I noticed that the stain had bubbled in spots. I am not sure what the cause of this is. Could be operator error as I am new to the spray gun. The doors were also drying outside, so I am also wondering if it is the result of being in the sunlight.
thanks again for the advice.
Joel
If I understand what you have so far is dye mixed with shellac--two coats, the first being 1 lb. cut, and the second 3 lb. cut (straight from the can). You can sand this gently to remove the nibs, being careful especially near edges to avoid cutting through. Use nothing coarser than 320 git. Or, you can wait to sand the nibs until you have applied a coat of varnish. It will be more difficult to sand, but with a bit less risk of cutting through the shellac/dye.
And of the core Waterlox products will work fine directly on the shellac just as you have used it. Adhesion won't be compromised since Waterlox varnish doesn't contain polyurethane. The Original/Sealer gives a very nice mellow shine, basically a semi-gloss. It is ready for wiping as it comes out of the can.
If you want a more satin finish, you can use Waterlox Satin. It is a bit thicker and you might add a dollop of thinner for easy wiping. Be sure it is well stirred before use, and every few minutes while you are applying it. By the way, it takes about 3 coats of Waterlox original to give the same thickness as one brushed on coat of "full strength" varnish.
Joel,Just to add a bit to Steve's post -You've already accomplished the "sanding sealer" step that I suggested. You've stained and sealed in one step.It's always a good idea, when applying a multi-layer finish, such as a varnish to use a first coat that assures that the entire film will adhere well to the substrate (wood). One way to do this is to use a dilute first coat of the same finish. A first coat of a varnish diluted with an equal volume of solvent is good. It brushes or wipes on effortlessly, flows out without any brush marks and penetrates somewhat into the wood. The next, full-strength varnish layer will adhere well if it's applied no later than a few days, or if the first coat is lightly scuffed to deal with having really hardened.A lot of people like to use shellac as the first coat. Shellac adheres tenaciously to just about any wood and almost any other finish will adhere very well to shellac. Any oil-based varnish will adhere to shellac whether it contains wax (as it does naturally) or if it's dewaxed. Polyurethanes and water-borne varnishes adhere best to de-waxed shellac.Don't get too intimidated by finishing. You can go from being a novice to being pretty experienced quickly. Don't make it over-complicated.1. Prepare the wood - carefully sand to about 150-220 grit.2. Stain or dye as desired. Deal with any raised grain issues with 220-320 grit.3. "Seal" with a dilute version of the final finish or shellac (about 2# cut). 2&3 can be combined as you have done.4. Apply several coats of the final finish.That's basically it.Shellac can be the entire finishing process. Using shellac or lacquer, each new coat completely dissolves the previous, resulting in one continuous thicker coat of all the applications without demarcations between. There is no question of adhesion with each new application.With varnish each new coat does not dissolve the previous. Adhesion will not generally be a problem if additional coats are applied within a day or two of the previous. Scuff sanding between coats can improve adhesion if the previous coat has cured longer than desired for re-coating.Aside from adhesion-improvement, "level sanding" or scuff sanding is the "trade secret" to anxiety-free, effortlessly-beautiful finishes, achieved in a calm process. Finishing is dreaded by many woodworkers as the hardest part of any project. They sweat bullets about dust in the surface and go crazy trying to make their finishing environment dust-free. They agonize over drips, sags and brush marks and generally consider the finish to be their enemy and a totally uncontrollable process. "Fear of Finishing" is a real entity in woodworking.No Fear. Reasonable finishing environment cleanliness is important, but that's all. Dust WILL get in the finish, especially in varnish with its long drying times. No problem.Level sanding, when dry, turns finishing into the same controlled, calm exercise as sanding the wood in the first place. Every application or every several applications (depending on the compulsiveness of the finisher) is sanded gently with 320 grit on a sanding block. The dust nibs and highest peaks of finish irregularities are removed. With each successive coat, the process results in wider and wider areas of smoothly-leveled finish.Just as a 50% solution of varnish is useful as the first coat, it's also useful as the very last coat as it flows out without any problems and self-levels very nicely.Whatever the finishing material, after it's dried, or cured, it can be "rubbed-out" as I described before - or can be left as is.Rich
Edited 5/8/2008 8:03 pm ET by Rich14
Very good explanation of the zen of finishing.
Thanks.
Rich & Steve,
There, your posts have been catalogued into a document that will be posted on the woodshop wall for future reference.
THANKS,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Rich,
Thank you very much for this terrific explanation. It's as good, if not better than anything I've ever read in a book on the subject.
I will take your zen approach. I must say, I have been a bit fearful of finishing myself. So hopefully this will all put an end to that. Your straightforward steps make it sound fairly simple.
Joel
Joel,Glad to help.I did describe in pretty broad "strokes." (pun intended).Also keep in mind that "God (or the devil) is in the details."Meaning, do each step of the process well.Good luck. Have fun.
Hey! Where's Frenchy? I thought for sure he'd chime in here, recommending flooding the surface of the doors with alcohol with a lick of shellac tossed in for good measure. I sure do miss that little guy...
ZoltonIf you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
I may get chewed up for this but what I do if I want a really glassy surface is I save some of that powdery sanding residue (the finest of the sawdust) from my processes, flood on a coat of finish, sprinkle the thing with the dust, then wipe off. Naturally, when this first coat dries, you have a bit of work to knock it back with a very fine grit sandpaper. But it really makes for a super smooth surface.
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