Hi Patrick,
There are many possible reasons for streak marks on your floor. It is pretty unlikely but it could be that your flooring contractor did an uneven sanding job. That would mean that he may have actually removed all of the old sealer in some places and left remnant of it in other spots.
He could have also applied the mineral spirits unevenly. Certain spots would be darker than others if some of the old sealer was still on some areas of the floor.
The most important thing is THREE coast of oil modified polyurethane. This ensures even coats and no streaking. If you have streak marks, it means that certain spots on your floor probably have more finish than other spots. If your floor finish is uneven, he may have done all of the right steps but if he never went over the finish, there very well could be streak marks left behind.
The solution to your streaky floor is to invite your flooring contractor back and get him to do another 2 coats of oil modified polyurethane.
The sanding job was done slightly incorrectly. You must screen the bare wood with 100 grit sandpaper before doing your staining job. 180 grit sandpaper is actually too high. Keep that in mind for the future. If you say your floor is smooth, that is great.
The most probable reason that you have streak marks is caused by either trowel marks or brush marks (depending what your floor contractor used as an applicator). This is what I do: I like to apply my first coat of polyurethane with a 12" drywall trowel. I usually thin the finish I use (Fabulon Brand heavy-duty poly satin but Duraseal is good too) about 3-5% when I am troweling it. This particular brand has a bit too much body for troweling. In my case want to slow the drying down on this first coat, so I add odorless mineral spirits. I want to prevent trowel marks. I pour a puddle of this slightly thinned finish on the floor, and work it back and forth (just like glue troweling).
Make sure he gives the surface a light sand only. He should only sand with 100 grit screen paper. This will bring him back to the bare wood. Make sure he does the entire floor if you want your finish to look even.
Good luck!
FOLLOW UP: Doc, I think we solved our problem. My contractor decided to try to buff out the streaks, and it works. Yeah!!!
You may also find these articles helpful:
1. Floor Types And Finishes
2. How To Apply Oil Based Polyurethane WITHOUT The Pits And Bubbles
3. Custom Staining Wood Floors Without The Blotchy Effect
4. Laquer Finish Floor Fires
5. How To Take Care Of Your Health And Safety when Installing, Finishing, Repairing or Cleaning your wood floors
I have 2,000 square ft. of 3 x 3 mesquite end
grain tiles. We have other hardwood floors in our house that
needed some attention, so we decided to reseal the mesquite why we
were at it. I used the same person who originally installed the
floors. When we first put them in 5 years ago we used satin
Duraseal to coat the floors with. They looked absolutely
beautiful. He has screened the floors with a 180 and 120 grit
paper to remove the old sealer and vacuumed the remnants up. He
then wiped the floors down with mineral spirits. Once the floors
were completely decontaminated he applied his Duraseal. After 24
hrs of drying the floors felt smooth but had the appearance of
streaks. He has now repeated the same process three more times
with the same results. Our last try we used a matte finish to see
if it helped. The floors have the same streaky appearance again.
How do we get rid of these streaks. PLEASE HELP, we want our pretty
floors back.
