What you are trying to do is remove as much of the stain possible.
Fixing a blotchy stained floor.
If the blotching isn t too severe try using a glaze to soften the contrast between the deeply colored and lighter areas.
Clean off all dust and wet the floor with warm water.
To apply liquid stripper spread it around evenly with a chip brush to create a nice thick layer.
This will require that you again use a.
Start by making a test board with your chosen sealer concentration.
This time apply a washcoat of shellac and then the stain.
You can also choose to sand it and even do both and just start over.
Use a polisher on the main area of the floor using 80 grit screens followed by 100 grit screen to remove scratches.
Wipe the brush off frequently as you work.
If you re using an oil based stain scrub the surface while it s.
Wipe off the excess with a rag immediately.
A few dark spots on the floor can be fixed using lightening techniques but if your entire floor is blotchy and uneven consider a whole floor approach.
For water based stains use a lacquer thinner.
If the surface is very blotchy you ll have to remove the stain by stripping sanding or both and start over.
The next step is critical.
Then the only answer isto use polyshades and just paint on the stain with the poly.
If the surface that you have is very blotchy you need to make sure that you will remove the stain first by stripping it.
Leave the stripper for 30 minutes then scrape away following the wood grain.
This will also even out the irregularities that may have occurred when sanding.
Scrub out the streaks then reapply the stain liberally.
If you do have a blotching that is not too severe then you can try and glaze it.
Also with plywood justmake sure you do not over sand and get into the glue from where the plies areput together this will leave the same blotchy finish.
If i do have some spots that donot stain just sand them again and reapply the stain.
Still wet with a scotch brite pad and mineral spirits or naptha.
One sure way to fix a blotchy stain is to sand it off and start over.
Apply pre stain wood conditioner which makes the porosity of the whole piece more uniform.
Repeat this process until you get to the desired color depth.
Let it dry and add a second layer of stain to all but one section.
First strip as much of the color as possible.
Apply a wash coat of shellac and then the statement.
If you remove too much restain that area and start over.
If you need a darker glaze to cover up the blotchy areas use just the tip of a dry natural bristle brush to distribute the stain instead of wiping it off until it s an even color.