CLEAR hardwood finishes? -- moisture cure, etc.

[JayB]

I now have a new unfinished red oak hardwood floor installed in an apartment that I will be renting out.

What I want is a truly *CLEAR* finish to put down on the new unfinished flooring.

I have extra flooring that I have set up so I can test various finishes. I have already tested a number of stains and, if I have to, I will go with one of those. But, what I really want is to be able to put a completely clear finish over the new unfinished hardwood flooring. I like the way it looks now and I would like to be able to keep that look and coloration. All of the so-called "clear" polyurethane finishes I have tried so far are not really clear. They are amber color, and they also stain and darken the wood grain.

Here are my two questions:

1) I am interested in clear Moisture Cure Urethane (one brand is made by Garco) -- but I can't find anywhere to buy it. It is supposed to be truly clear. I know it is super volatile and maybe that's why it is not easily available. I can apparently buy it online, but then I have to wait 4 to 14 days for it to arrive. Does anyone know where I can go in person and buy this stuff? I am in New Jersey near Philadelphia, PA.

2) I haven't tested out water-based polyurethane products yet. I get the impression that they can be more clear than oil-based polyurethane. MinWax sells a clear water-based base coat and a clear water-based polyurethane that goes over the base coat. The clear base coat is supposed to seal the tannins (or something like that) in the wood so it doesn't darken, and then hopefully the top coat won't darken the wood when it is applied.

Are water-based polyurethane finishes okay for hardwood floors? Are they durable enough compared to oil-based polyurethanes? Are there any special cleaning requirements or instructions for water-based finishes that are different than for oil-based polyurethane finishes?

Can I later cover a water-based polyurethane finish with an oil-based polyurethane finish? I think the answer to that one is "no", but I thought I would ask anyway.

[charlie]

water based are more clear than oil based, and have a slightly blue tint rather than yellow. they do use water based for floors, but you may have to recoat more often as they may not be as hard.

ask the rest of your questions on rec.woodworking.

[jamesgangnc]

You need to use water based if you wish to avoid yellowing. Most people never really notice the yellowing though and oil based coating have been used for a really long time.

[salty]

In a rental, the primary consideration should be durability, not slight yellowing. What will it look like in 5 years?

[norminn]

I don't know of a clear coat that doesn't darken wood to some extend. Of course, a very light wood like maple will darken the least. I've refinished lots of wood and have not used sealers (only stain and varnish). What kind of wood is it? Pine and oak yellow considerably exposed to sunlight, regardless of whether water or solvent based finish.

Sealing in the tannins applies to color that bleeds through and stains a painted finish ... cedar, redwood have more tannins.

The main thing about oil and water is that they do not mix when liquid. An old finish, if properly prepared, can generally be covered with the other type as long as instructions are followed for the product.

[JayB]

Thanks. I'll have to see how the water-based stuff looks, and see if it is clear enough and doesn't darken the wood grain like the so-called "clear" oil-based stuff does..

And, thanks for the tip about rec.woodworking. I'll post my questions there. Hopefully that group is as good as this one in terms of people providing answers and trying to help.

[JayB]

Thanks. It's not really the slight yellowing that I am concerned about. It's the way it really darkens the grain of the unfinished hardwood -- almost like a stain -- that is what I am trying to avoid.

[JayB]

The wood is unfinished, #2 red oak.

Yep, it's red oak.

That's interesting. "Maybe" that means that I can do the job with clear water-based base coat and top coats for now. And then, sometime later on maybe cover that with clear oil-based polyurethane for more durability.

[ransley]

You want durability its a rental that will be abused, not your living room. Gloss is clearest and most durable , what makes a lower sheen makes finishes softer and cloudy. Water base is not as durable from what I have been told but has no color and doesnt amber like oil. dont bother staining you are making more work for yourself and oil poly ambers nicely. A few coats of gloss oil followed by a finish coat of satin looks great. With a rental more coats is better I try to get

3-4. If you stain then recoating in a few years if there is damage might mean sanding to wood, with no stain recoating is much easier when there is damage

[jamesgangnc]

I'm thinking any red oak is going to darken a good bit when covered with oil or water based clears. You should choose the wood based on the finished appearance you are seeking.

Perhaps you can try white washing it a bit before sealing. I have some cabinets that are oak and have that finish. Basically just wipe down with a cloth and some white paint. Wipe as much paint off as you can. What's left will be in the grain. Let dry. When covered with clear coat the results are pretty light.

[dadiOH]

They are amber because they are oil based. They don't stain the wood, they wet it. Most people like that because it accentuates the grain. If you put oil base poly (3-4 coats) on a light wood the wood will be noticeably yellower.

Water base polys are white when liquid, clear when dry; however, they too wet the wood just much less than oil poly.

Someone told you about using a wiped off wash of white paint to avoid the penetration of the clear top coat. That works and will give you an appearance pretty close to the raw wood. Best to dilute the oil paint about

50/50 with thinner. The downside is that the non-penetration of the top coat means it is stuck to the residual paint, not the wood; however, I have never had any problem doing it...all my now 14 year old butternut kitchen cabinets are white washed.

You should be aware that regardless of what clear top coat you use the wood is going to change color over time and exposure to light. Generally, that change is darker.

_____________

Lots of luck with that. What happens if the wood has no tannins? Many don't.

__________________

Yes

Yes

None I know of. Most important thing is to keep grit swept up. Polys resist scratches well but grit will eventually get them too. Especially if you used glossy rather than semi-gloss (more noticeable on gloss).

Yes. And vice versa assuming the one being covered is totally dry and/or fully cured. However, unless the old surface is pretty worn it needs to be lightly sanded to promote adhesion.

[JayB]

....If you stain then recoating in a few years if there is damage might mean sanding to wood, with no stain recoating is much easier when there is damage....

Yes, that's one of the reasons that I was thinking of just using a clear finish and no staining. Unfortunately, the "clear" polyurethane finishes makes the wood look bad -- as if it was poorly stained.

[norminn]

Can you elaborate on how it looks "bad"? Geesh...red oak should be beautiful! I don't know flooring or wood grades involved in new mfg. flooring, just lots of old furniture. Is the flooring a brand name?

[JayB]

I bought it at Lumber Liquidators (

). It's unfinished #2 Red Oak (with their product number of RO22, I think). The way it looks bad is that the grain absorbs the clear polyurethane and what started out as a very light colored wood becomes dark, blotchy, grainy, junky-looking wood. When I apply any color of oil-based stain, the stain absorbs in a way that the wood grain looks and is whatever color the stain makes it. But applying clear polyurethane doesn't do the same thing.

[JayB]

My latest frustration is that I went to 3 stores (Home Depot, Lowes, and Ace Hardware) to find Minwax® Water Based Polyurethane for Floors Professional Formula and Minwax® Water Based Polyurethane for Floors Base Coat, and none of the 3 stores had it.

[norminn]

With clear finish, oak generally is a mid-tone to deep brown, even without any stain. And it is very "grainy". It might help if you upload some pix and post a link, at least for the areas you consider problems. A good way to get a close idea of how wood will look with a clear finish is to simply wet it with solvent. Any chance you can replace some of the worst looking boards?

I took a look at the link you provided and went to the product...RO22 is called "rustic", as opposed to other red oak called "select" and some called "natural". If some of the wood is much harder, accounting for the very light look, you can blend them using stain if you apply the stain and don't wipe it off the light spots. I haven't done flooring, but lots of furniture, and have mixed my own stains. If you apply half-strength stain to the entire floor, you can help blend very light spots by brushing on same stain, full-strength and not wiping it off. Sort of a half-assed way of fixing something you apparently didn't expect when you purchased. I'll cross-post this and see if woodworkers have some better ideas.

I assume you wipe the stain?

[salty]

Whatever you do, don't go to a PAINT store!

[hrhofmann]

What about using a wood filler that is supposed to reduce stain absorbtion and reduce blotchiness?

[JayB]

Maybe that's the problem. I was hoping to be able to apply a completely clear finish and have it look pretty much the way it looks now unfinished, but with a clear finsih on top. I guess that won't happen.

In my original post, I was also asking about clear Moisture Cure Urethane. The impression I got is that when it goes on it doesn't really change the color or look of the wood. I think they said that is what is used on bowling alleys. I don't know if all of that is true, but it doesn't matter anyway because I can't find any places to buy the stuff other than online.

Replacing boards won't be a realsitic option at this point. And, I don't think I'll get to do the picture idea. Since today is Saturday, I need to figure out something and get this done this weekend.

I have a hunch that what I am going to end up doing is picking one of the stains that I already tested and go with that. The stains all darken and even out the color variations, and some of them look okay enough to go with (I'm leaning toward Colonial Maple or Golden Pecan). Maybe it won't be exactly what I was hoping for -- just a clear finish over the unfinished wood -- but it will be done.

Yes, I did do what the instructions said about applying the stain, leaving it there for a certain amount of time, and then wiping it. I thought it was fairly interesting the way the stains worked and looked by doing that. Earlier I had tried MinWax "Polyshades" which is a combination of stain and polyurethane in one. That was okay, and it would be a lot easier, but then I read that Polyshades is not supposed to be used on floors -- I am not sure why -- so I guess that's out.

Thanks for all of your help and suggestions. It does appear that you know a lot about all of this and have a lot of experience with it.

[norminn]

Most good paint stores ... Sherwin Williams, Ben Moore...carry Minwax products. A real paint store is a good place to make friends:o) The issue you are dealing with is a less than ideal selection of wood....if you read the details of each type of red oak on the website, you will see that. The "rustic" grade is the leftovers, with knots, less-than-desireable grain, etc. Always a good learning experience :o) You still have a good solid floor that will take lots of wear and tear

- unless there is a flood or animals toileting on oak floors, it is hard to damage it. Done properly, it is also pretty easy to maintain. Taking off shoes at the door will help :o) I'd take solid oak before pergo-type c=== any day.

I stripped oak kitchen cabinets for a friend once because I was out of work and needed money. Only after I slathered on paint remover did I realize the end panels of the cabinets were not solid oak like rest of the cabinet...they were particle board with printed grain. I was already on the verge of nervous breakdown and that almost put me over the edge. I got out my art stuff and between wood stain and a few brush strokes with oil paint I was able to fake the grain pretty well. Not obvious. I also painted fake woodgrain on floor boards for a doll house. If you have spots that really stick out like a sore thumb, you can paint in - with a light touch - enough grain to camouflage the spots before you do final finish.