I'm a real gadget nut. Any new tool offered to us floor sanders, to do a better or easier job, I usually give it a try. In most cases I'm pretty disapointed by the claims of manufacturers, espesially when it comes to sanding machines . Most of the hand held random orbital sanders, for instance work well on softwoods, but don't have the power or weight to work on hardwoods. They also leave their own distinct sanding marks when you apply a stain to the wood. There have been some improvements in the big drum sanders when they moved to the sanding belt, but this has still not eliminated the chatter marks often seen on a fine sanded hardwood floor. It seems as soon as you pass a machine over a floor you can see its path. Nothing seems to disturb my customers more than to see the marks of these sanding machines once the floor is finished. You can imagine why prefinished floors have become so popular.
Well, we still have to use sanding machines on the existing hardwood floors. The rental drum sanding machines are difficult to use and are very underpowered. For best results, you really need a training session with this sander and it's not a good idea to train on your own floor. But most of the rental companies have no spare hardwood deck where you can try these machines out. So most people go home and gouge and hack at their floors until toward the end of the job, they finally get the hang of it. Unfortunetly most of the mistakes are made with the coarse paper and are just about impossible to remove with the fine paper. Then the d.i.y.'er declares after the bumpy job is finished "NEVER AGAIN".
In the early 90's the Flecto® company came out with a partial solution to this dilema with the introduction of the Squar Buff Sander ® . At first I thought it was just another gimmick to sell some more of their exellent finish. I have to admit I was somewhat afraid that this machine might take some of my floor sanding work away and put it into the hands of the ametures. Well sometimes we need to explore what we are afraid of .
I had done a major repair job on a bedroom hardwood floor for some clients in my neighbourhood about 7 years ago and just last month got call from them to see what I could do for the main floor. I remember that job, 7 years ago (I have a photographic memory for floors, not people). I thought their main floor was in good shape. It had been sanded and refinished just before they bought the house, so all my work had to do with the upstairs floors. But now, alas, the finish on the main floor was giving way to large grey patches and everytime they washed the floor it got greyer and greyer. Well this 100 year old floor was about 2" wide but only 3/8" in depth and the last time it was sanded was the last time it should have been sanded. The finish that the previous owners had used was a lacquer sealer base coat and a single thin coat of polyurethane applied without scuffing the sealer. This one day job is cheap, but as the harder polyurethane gets impacted over the softer sealer, it cracks and soon the wood is unsealed and subject to water damage. Does this sound familiar ?
What to do, what to do? Well I thought here's a chance to try out a new gadget; the orbital floor sander. I confirmed that they had never waxed this floor and the finish was brand new when they moved in 7 years ago. They never used any soap , oil or polish on it either. So here was a unique oportunity. If I used only fine 80 grit sandpaper I could gently buff out the grey spots and touch them up with 2 coats of poly, then recoat the whole floor with a final coat. The owners had actually recoated the small hallway some years before so it confirmed that the new finish would stick to the old one. Other wise I would have done a finish test patch and waited a week and razor cross hatched the spot and applied duct tape and ripped it off. This is the acid test for finish compatability and should always be done before every recoating job.
The job was priced and confirmed. In a few weeks I was off to the local Home Depot and rented an orbital floor sander by Alto ®, which is virtually identical to the Flecto Squar Buff ® machine. It was early in the morning at the store, we were all a little sleepy, and the rental salesman assumed I knew how to operate the machine, so we didn't plug it in and test it. BIG MISTAKE. I got to the job and plugged it in and it wouldn't start. I called Home Depot and talked to the rental manager and she concluded that the machine was broken. Well it wasn't. But back I went to Home Depot and in a few seconds I was shown the saftey button to press before the main switch lever is pulled. A great feature, but because I didn't have one on any of my machines, I didn't look for it. Boy, was I embarassed. The nice manager appologized and turned back the clock on my half day rental so the only loss was my pride and one hour of my time.
Back on the job, and back on the floor, everything else went swimmingly. The 80 grit sandpaper, as I predicted, easily went through the grey spots and didn't chew through the good finish too much. I waited until the machine had sanded all the grey areas, then went over the whole floor with the dull sandpaper. There was not much dust made in the whole operation but the silly little vacum on top of the machine sucked up almost nothing. After vacuming I took a good look at the floor and was happy to see most of the grey gone and not much in the way of sanding marks. I was finished with that machine, so I started up my Porter Cable ® 1/2 sheet sander and with 80 grit floor sanding paper attacked the edges where the orbital floor machine couldn't get. With a little hand pressure this little machine did about the same job as the big one but about 10 times slower !
Once I finished with both machines I vacuumed very carefully and then poured a puddle of polyurethane on the floor and using a 12" steel drywall trowel, skimmed a single coat on that room. I could see right away that my guess was correct, the grey was gone. Even though some of the deep scratches had gone very dark with the coat of poly, the overall results were good. The next day I screened the room again with my regular buffing machine. Then I brushed on another coat. Two days later I screened the whole ground floor and brushed on one final coating. Boy, did it come out beautiful, the owners thought so too.
In conclusion I would suggest in the right circumstances you might try this orbital floor sander . But I would guess it will have it's limitations. I did notice that even with 80 grit sandpaper the machine left little circular marks in the wood. If one was to pigment stain the floor, these would really show up. But I was lucky to have a clear finish to apply so my marks were not visable. I would not try to use anything coarser than 60 grit and then finish off with the 80. The marks made by the 24 or 36 grit sand paper would be so deep that this little machine wouldn't be able to take them out with the finer paper. You may not be able to tell if the floor has been fine sanded until the stain or the finish goes on and by then it is too late.
If you want to sand off the finish on an old floor, using this machine, it will take forevever and a day. Unless you were very diligent, there will be sanding marks in the wood and clouds of dust throughout the house. It also doesn't have the power to sand off the overwood of a newly installed floor . A drum sander will do both of these tasks easily and quickly. Better yet, hire a pro for these jobs, and do the finish yourself, that's the fun part anyway.