My husband and I have been working on refinishing our oak floors. We took material off first with a drum sander and then used an orbital sander up through 100 grit. We started staining yesterday and the stain is extremely uneven and blotchy. It also looks a lot lighter than we expected.

Is this an issue with the stain? Did we have to water pop? Did we just not sand enough?

We looked through multiple forums and can't seem to find another issue that looks close to ours.

Link to the picture: http://i.imgur.com/rHa3VC2.jpg

Water-popping will definitely give you a darker stain, since it opens up the grain of the wood and lets it accept more of the stain. It will also help make the stain more consistent.

I don't know whether you'll get that consistency if you stop at 100 grit, though. We use a buffer to do the final sanding, using 120 to 150 grit screens. (Screens are black carbon discs) The buffer covers every bit of the floor--both the edger areas and the big machine areas.

Using a buffer is something that was never mentioned in the homeowner articles and books, or in the rental machine brochures. I know--I was self-taught at the beginning, and those books just didn't cut it. In those articles, flooring sanding always stopped at 100 grit on both machines, and then a natural sealer. You can get away with not buffing if it's just a sealer. As you found out, a stain is not so forgiving. It shows every machine mark and all the uneven sanding.

It's harder to use a buffer without some practice. I briefly looked at Youtube, and the videos titled "Using a buffer" are mainly about using one for polishing, waxing, and so on. You might learn technique from those videos, but I'd look for a video on doing floors that specifically talks about using the buffer for screening a hardwood floor.

For a stain, we use 120 paper on the edger, and 100 or 120 paper on the big machine. We scrape all the end walls out about a foot--that gets rid of any marks that the edger leaves. Then we use an orbital sander with 150 grit paper, or hand-sand all the end walls with 120. After that, we apply water evenly with a wrung-out rag, and let it dry for a few hours.

You can walk on the water-treated floor, but you need to be careful of scuffing it with your toes while you're applying the stain, or wiping it off. The scuffs will show.

If you don't care to use a buffer, you have other options. I've not used them, but the square-buff machines at the rental places may be useful for getting an even sanding, with 120 or 150. They're easy to use.



Was this a small, hand-held orbital, or some type of stand-up rental machine? If it was a stand-up machine, going to a finer grit and using water treatment should make the floor appearance more even. If you don't want to scrape end walls, you can spend more time sanding out edger marks with a 100 grit paper on the orbital. Then hand-sand them with 120--it doesn't have to be heavy sanding, but enough to take out the small squiggles that 100 grit paper leaves.

The main thing here is that you want consistency. Some combination of more even sanding and water application will help you get that. What I'm describing above is the pooled experience of three different floor companies, and we're always trying new techniques. But this is tried-and-true stuff.

the stain is uneven due to uneven sanding .

the floor is lighter in color becausr you used an orbital sander with a fine grit and closed up the grain too much.

you can use an orbital after you sand correctly with a drum machine if at least 2 cuts..

you must use a rougher grit on the orbital to compensate or it will be fine.

when we use an orbital we put a 60 frit paper on it.

I find this keeps the original sanding consistent without closing up the grain to tightly.

water popping wont help inconsistent sanding deficiencies.

.


for staining anything over 100 grit is too high and will alter color considerably.

Thank you, Alloy7 and JamesTRD, so much for your inputs! We used a 12" x 18" Orbital Sander for the final passes with the 100 grit paper. We also scraped the edges and the corners to get rid of the swirl marks before trying to even everything out with the Orbital. The bathroom which we tried staining first does have the roughest finish because we had a hard time getting large equipment into such a small space.
Surprisingly, even though some scratches and marks got revealed by the stain they are not as bad and multiple as we were fearing. The stain just did not go on evenly.
After the bathroom fiasco, we were too afraid to try staining any other rooms which we are hoping we sanded a lot better because we had more room to turn around in.

For the rooms where we have not tried staining yet, should we try doing more passes with the Orbital and water pop before staining? If the problem is that we closed off the grain, can we go a lower grit on the Orbital? Or do we need to start over and go back to the drum sander to make sure we remove enough material and ensure our later passes result in even and consistent sanding? Because our floors were in pretty good shape, we only did a couple passes with 36 grit on the drum sander in the areas with most wear and 60 grit on the drum sander in the bedrooms. Did we not remove enough material to begin with?

I cant properly advise you from a forum.

I would say starting over is your best chance..if you use the oribital don't go higher than a 60 grit on it. let the stain penetrate some then wipe excess.

Zhenya wrote:


I'd say that you need to get the drum sander grit to at least 80 before you use the orbital. It's too big a jump to go from 36 drum to 100 on the orbital, and it's better if all the rooms are sanded with the same grit on the drum.

James wrote:


As long as you water pop the floor, Zhenya, then you'll open up the grain again, and the color will be dark. Our 150 screening is probably overkill, but it gets rid of any marks, and once we water-pop, the floor opens up and the stain takes dark. We did a Duraseal ebony stain the other day, and it was nearly black. Without water treatment, it comes out gray.

James wrote:


With buffing the floor, we don't leave it to chance. I used to not water-treat, and the 120 screens would make everything smooth and even. The stain took well enough that the floor matched the samples, and the customers were happy.

I was leery of water treating for many years, and only used it a few times. For one thing, I was told it had to dry overnight. This messed with the schedule. Then I teamed up with guys who used water-popping all the time, and I got familiar with it. Seeing that it only needed a hour or so to dry made a big difference.

But since I started out not relying on water treatment, I had to make sure I had sanding consistency every time on stains.


Whatever grit you end up with on the orbital, it's the consistency that's important--make sure the orbital goes everywhere, and use a hand-held orbital for tight places like the bathroom.