I'm staining 3/4" plywood with an Oak veneer, both sides. Wood was never finished or stained before. First, I wiped everything down with mineral spirits, then let it rest over night. Next, I used minwax dark walnut, and following the instuctions on the can, applied two coats.

instructions: apply stain, wait 5-15 minutes (i waited close to 15) then wipe off excess. Apply a second coat 4-6 hours later. I waited 4 1/2 hours, then repeated the process. I did not use any pre-stain solution.

I was happy with the initial result except for a couple areas which seemed too light. My thinking was that at this point the stain had already penetrated at dried, so my best move was to sand off those areas and re-apply the stain. I was thinking maybe some sort of chemical or factor process may have caused the lightening. So I sanded off the stain in those areas, not going too deeply into the veneer. I went beyond the areas in question thinking I'd sort of "feather" the new stain back in.

Long story short, it's not working. I've reapplied the stain to the newly sanded areas and now the whole area I re-sanded is lighter, not just the initial area that seemed off. I used 100 grit paper which I thought was pretty rough. Initially, I really didn't sand the plywood at all before applying the stain.

I can't understand why the freshly sanded areas won't take the stain to make it dark enough to match the rest of the wood. Is the old stain in there acting like a sealing against new stain even though I thought I sanded most if not all of it out? Should I let stain really dry out for a few days then go back and resand it off? Should I use a solvent on it?

I'm about out of options. This is part of a desk I spent a lot of time building and now I'm crushed. The veneer won't stand much more sanding.

If I sand off again, is there a better method for applying the stain that what I'm using? I was thinking maybe if I put plastic wrap over the stain and let it sit it would make it penetrate more?

Sorry for the long post. I'm really at my wits end. Thanks for the help.

 

Yes, I would say the stain has partially "sealed" the wood, which is why it won't get as dark as it was originally. Not sanding both surfaces entirely before you began was likely the cause of the inconsistent finish, but you probably already knew that.

IMO, you will probably never get it to match perfectly, but your best bet will probably be to resand the ENTIRE side rather than just part of it (no way that would ever work) in hopes that, if nothing else, you can get it all to be consistent in color. 120 grit would be the lowest I would go.

I'm not a big fan of the darker Minwax stains... much of the color will often wipe off, no matter how long it's left on the wood. You could try switching to a Sherwin Williams Wood Classic stain, I have always been very happy with it. It's a lot thicker (more pigments) and seems to tint more evenly, compared to Minwax, which is always oily and runny.

 

I think your best bet at this point is to work on getting the stain consistent. If the end result is too light you can always apply a coat of tinted poly to get it darker. I've never been a fan of multiple coats of stain.

 

It was lighter and you sanded it all off. That makes no since to me. Just applying more stain in that area is what I would have done to make it darker.
No way would I have applied stain without sanding first.
Using gel stain would have given you a more even finish.
You used Oak veneer plywood and tried to stain it with dark walnut stain. That also makes no since to me.

 

Trying to sand a small area and restain is never going to work. You will get overlap marks. You should have sanded the plywood before your initial staining anyhow. Sand off all the stain you put on. Oak has an open grain so you won't be able to get the stain out that's down in the pores of the wood. That's ok. You will be able to get 99% of it out. Then restain. I would not let the stain sit long enough so that it dries. Wipe it off before that happens.

 

Thanks everyone for the help.

I agree I should have done a better job sanding before staining. Actually I did a very light touch sort of skim sanding because testing suggested that the rougher surface took the stain better and I wanted it dark. (dark walnut) I'm willing to take the blame for this, but I'm actually thinking the initial problems may have had something to do with some flaw in the ply or perhaps come chemical that got it at the lumber store. I guess I'll never know for sure.

I think xsleeper had it right. I sanded as deeply as I dared and it seems I got to the original wood color, but it's as if the original coat of stain penetrated deep into the veneer and has some how sealed the wood enough so that I can't get a darker stain on second attempt. I've done test sand/restains in other areas and confirmed this to be true. The veneer is of course very thin.

This project was actually a desk and it's really the desk top that turned out poorly so I'm just going to go buy another sheet of oak ply and start over just for the top. I agree minwax is poor stain, but I want it to match the rest of the desk so I'm stuck with it for this project.

Few more questions....

1) Is it true that the rougher you leave the surface of oak, the darker the stain will be or is this just self-deception on my part? If so, what's the roughest sand paper I can use before staining? Alternatively, what's the typical recommendation for grit for oak before staining?

2) Is there such a thing as a stain "darkener"?

3) My plan for the stain is the same as before. Apply, let it sit for about 10 minutes, wipe it off, then repeat 5 hours later. When I wipe it off am supposed to rub it out like rubbing wax off a car or do I want to do it lightly to just mop up the excess?

4) I know there are pre-stain products available to help even out the stain prior to staining. Is this worth doing? Will it make the overall stain lighter in color?

Replies appreciated, even partial ones.

 

#1 - sort of, fine sanding will close up the grain and make it harder for the wood to accept the stain. Sand with 120-150 grit with the direction of the grain.

#2 - no

#3 - I normally wipe the stain within 5 minutes of application. Basically you are just wiping off the excess. I'm not a fan of multiple coats of stain! The 1st coat somewhat seals the wood which makes it difficult for the 2nd coat to be absorbed. Stain dries more by absorption and not chemically on top of the wood. Excess stain is often 'remelted' and pickup by the solvents when the 1st coat of poly is applied. If one coat of stain doesn't get the wood dark enough, I'd poly it, sand when dry and then apply a coat of tinted poly to get the desired color.

#4 - a wood conditioner will slightly seal the wood making any stain applied to be slightly lighter in color.

 

Adding one more question....

They make stain or stain matching markers. Do they make ones that can be used before the finish? (You apply the finish over them) If I have any very small flaws that didn't color right I might like to try this method. Also, laugh if you want, but what if I just used a Sharpie (felt tip marker)? Could I apply a poly finish over that or is there something in the marker that would repeal the finish? (minwax wipe on is the plan).

 

I'll chime in too... I'm pretty sure my answers will be similar to Marksr's but...

I'll preface it with this: Plywood- especially cheaper grades- can sometimes have areas that come out blotchy and uneven, even if you prepared them perfectly. It's possible you just got a bad sheet.

1). Yes, that's true in some ways. This is why you would need to evenly sand everything from the start. Let's say an area is scuffed, or marked. So you sand that one area. It's likely that the sanded area will accept stain slightly differently than other areas that were not sanded. When sanding a solid oak board (not plywood) the end grain will always be lighter than the face grain. For this reason, some will sand the end grain with 80 grit, while sanding the face grain clear up to 180 grit so that the stain "takes" evenly to both surfaces... because sanding can either open or close the wood pores.

2). no... but I have heard of a stain recipe that includes mixing in roofing tar... mainly it is used to give wood an "antique" type of finish... I wouldn't recommend it! LOL

3). Like Mark, I wipe the stain fairly quickly, within 5 minutes... before it becomes sticky. Staining a 2nd time usually has no effect if you have put enough stain on the 1st time to really penetrate the wood. I agree that tinting the poly is the best way to slowly darken the wood.

4). Definitely do NOT use wood conditioner on oak plywood. Wood conditioner pre-soaks the wood so that it does not absorb as much stain, causing a more even (and lighter) finish. It is best used on softer woods like pine, poplar, maple, birch.

5). A furniture repair marker can be used anytime. I suppose it would be possible that brushing on the poly might smear the ink from the marker around.

One other thought... anytime I have ever used Minwax dark walnut stain (and many other of their dark pigment colors) on oak, it will bleed out of the pores even after it's been wiped. So watch for that. You might have to wipe it several times. But this is more pronounced on solid oak, not as much on oak plywood.

 

Around 40 yrs ago I was on a job [painting new gov't apartments] and to save money we'd pick up a several roofing shingles, break them up and drown them in a 5 gallon bucket of mineral spirits. A couple of days later we'd use the 'dirty' mineral spirits as our stain. The longer the shingles soaked [or the more you used] the darker the stain would be. I had forgotten all about that 'recipe'

I suppose you could darken up the stain some with dissolved tar but it would be better to add more colorant or a little of an appropriate paint to darken the stain. IMO stain, poly and then a tinted poly is a better method.

 

Follow up questions...

Just got back with my new oak ply for the desktop. I've got some work to do on it first but after that I'll follow the advice of Marks and xsleeper and others, I'm going to hit it with 120 grit, then apply the stain for 5 minutes and wipe it off. I'd really like to get it dark as possible, so as per the can instructions, I might follow up 5 hours later with another coat. (I'll skip the pre-stain as I need to try to get it as dark as the rest of the desk).

a) Actually, after I sand and before I stain I was planning to wipe it all down with mineral spirits. Maybe wait a two hours for it to dry then hit it with stain. Is this okay to do? A waste of time?

b) When I wipe off the stain, is the idea to just wipe off once to get the excess or it it better practice to sort of rub it out like you do when waxing a car?

c) After the final coat of stain has been wiped, is 12 hours a long enough wait before applying the minwax wipe-on poly? Either way, I'll check on it and wipe a few extra times as suggested by xsleeper regarding the pores.

d) Speaking of minwax wipe-on poly, does anyone have a problem with it? A friend of mine recommended it. He also told me minwax stain was krap, but not until after I'd used it. I'm not crazy about the stain-poly combos. I haven't heard a lot of praise for them. Doesn't the finish look less "deep" or cloudy somehow?

Thanks all. This forum is an awesome resource.

 

a - you can clean off any contaminants by washing with mineral spirits. As long as the thinner has evaporated well - it won't hurt anything, if you stain too soon - it might lighten/thin the stain some.

b - just wipe off the excess

c - I've never used the wipe on poly. IMO it doesn't give enough film thickness to offer the protection and finished look I want. Drying times vary. Cool temps and/or high humidity can slow down drying times. If the stain hasn't sufficiently dried, the poly can rewet it and lift it off of the wood.

I've never had any issues with Minwax products. There are some better stains/polys but there are also worse ones.

 

In my opinion, the Minwax stains are very oily and make it very user friendly for someone who doesn't have a lot of experience applying stain. It's more difficult to get lap marks with Minwax than with a more professional stain. I have also found it takes a long time to dry. Especially with oak because of the reasons mentioned earlier. The open pores of the oak hold a lot of stain and it can come out even after you have wiped. For this reason I would give it at least 24 hours or longer before you top coat with poly. Be sure to hang your stain rags to dry. Leaving them bunched up in a ball can start a fire.

 

I agree with drooplug 100%... wait at least 24 hrs to poly. The darker colors take longer to dry, esp on oak. I wouldn't clean the wood at all with mineral spirits, never have- no reason to. I could see how the mineral spirits could soak into the wood, almost like a wood conditioner... so IMO, I would skip that. Maybe if you wait long enough it would have no effect but I wouldn't risk it.

I don't care for Minwax poly much at all. It's very thin and doesn't build a thick coat fast enough to suit me. As for the Minwax polyshades products, many don't have good results with it. IMO it is best when sprayed. When brushing it, a novice can make some bad looking brush strokes that are then permanently in the finish. I rarely recommend it. I suppose a lot of it depends on your technique as to how it turns out.

 

I appreciate all the staining advice and will follow it.

As for the minwax wipe-on, a friend of mine who refinishes furniture professionally suggested it. He told me to use a small (3" square) t-shirt rag and apply the first coat, wait a full day, then add another and so on expecting to end up with 4-5 coats. He only recommended I sand prior to the last coat using 4 ought steel wool, then tact cloth, then final coat. These instructions might have been tailor made for my amateur attempts, but if anyone has a better product or procedure to recommend, I'm all ears. Thanks.

 

Not a fan of steel wool at all. It creates a lot of fine steel fibers that are hard to completely remove. If you do use it, then his method is probably best because you are only doing it once. Steel wool and water based polyurethanes definitely should not be used together. Miss one fiber in the pores of your wood and it can rust when it contacts the water based poly. Hopefully you are using an oil based poly and that won't be an issue.

I'd suggest very light sanding between each coat using 220 grit sandpaper or the "fine" 180 grit 3M sandblaster sanding sponge. Cleaning after each sanding with a tack cloth, lightly moistened with a bit of thinner. The sanding between coats is meant to remove any impurities like dust that settle on the still wet finish, or debris that got in the brush and poly. Sanding between coats also helps with the adhesion of the following coats. Waiting until the final coat to sand would mean you've just embedded 4 coats worth of junk in your finish. If you were working in a really clean environment with negative pressure and exhaust hoods... maybe. For most of the rest of us, I'd suggest light sanding between coats. And I mean "light". You don't need to abrade every square inch. If it feels smooth it probably is, and there's no need to sand more than you have to. Your tack cloth will snag on anything you've missed.

Definitely don't put a fan on your project to help it dry. All that does is blow crap at your wet finish. Do it in an area that is calm and still. (not in the garage with the garage door open!... unless there is absolutely no wind) I will usually have a clamp on work lite and a 300 watt bulb above me, to cast plenty of light on the subject.

 

Got my stain on the new board and it turned out great! Thanks everyone for the help.


xsleeper,
That's good advice although in the past I have tended to oversand between coats despite my best intentions which is a particular problem when putting on several thin coats. Could you use finer sand paper like 400? What about wet/dry sandpaper like they use for automotive? If the finish was totally dry could you use water with the paper or is that just asking for trouble with an oil based finish? I'm surprised steel wool poses a problem if you are actually waiting a full day between coats. You'd think the surface would be hard enough to not allow bits of the wool to stick in it.

Oh, and what about the final coat. I'm actually building this desk in components so I can fit it through an office door. After it's all done should I wait a few days before re-assembly or it is pretty much good to go 24 hours after the final coat?

I'm not using water based poly. I tried that many years ago on a kitchen table and found it harder to work with. Also, it clouds up when damp. Now years later, it's breaking down and some things like envelopes or magazines are starting to stick to it.

 

Ya, oil base coatings generally dry to a harder film than their water based counterpart.

I've never seen a reason to use sandpaper finer than 220 grit on wood finishes. I wouldn't wet sand. It generally takes oil base coatings 72 hrs to cure so it would be best to wait a few days. You can do it after 24 hrs but you need to be more careful.

 

You don't need to sand that much with the 220. Just enough to knock down any nibs and to scuff the surface a bit for adhesion.

 

drooplug,

I guess I was more worried about dust than adhesion, but I'll tread super lightly.

marksr,

Thanks for all your posts here. 72 huh? I'll wait that long after the final coat and before reassembly. I'll wait overnight in between coats along the way. I have the time so best to play it safe and make sure it's dry.

 

I think you could assemble it 24 hrs after the final coat without any problems... you would just be careful with the pieces so as not to scratch them or slide them one on the other. One thing you don't want to do is stack the pieces. They may seem dry, but when you stack freshly finished wood together and let it sit for a while, the polyurethane will stick one piece to the next. As Marksr said, poly takes a long time to cure... I have heard up to 30 days actually. One article I read talked about how the poly continues to form molecular bonds with itself (which is why the finish is so hard) and gets harder and harder during that cure time. Surprisingly, that means it will want to molecularly bond with the next piece if stacked together. I guess maybe "molecularly bond" is just a fancy way of saying it wants to "stick together". LOL

The place the steel wool fibers will want to stick is in the pores of the oak. Oak plywood may not be as bad as solid oak, because the pores on solid oak are pretty deep, and even the poly doesn't fully fill those pores, so debris can settle down in there that your tack cloth might miss.

 

xsleeper,

Good to know. In my case it's three components that sit underneath a desktop. Two of the components are bolted together, then all of it it bolted up into the desktop. Does this mean if I don't wait 30 days it's likely the thing will fuse together in such a way as to not be able to ever take it apart again without the finish looking terrible?

 

I think that when the time comes I'll just put a little parchment paper in places where the components will touch after being bolted together. I probably won't even notice it, but if I do, I can just remove it after a month. That should head off any molecular bonding, I hope.

Thanks again everyone for the nuanced advice. Much appreciated.