You could try an abrasive on a thin grinder, but it would be a miserable job and, having spent a lot of time with grinders, I would say it won't be the safest job to do. Gloves, eye protection etc a must. You could run a router down the seam but you will remove a little bit of material. Again, safety is the issue here. A multi tool with abrasives might do too. I have the Fein MT. I say it is the one tool I can't afford to use except in extreme need. The blades and abrasives are serious dough and do not last.

Just a suggestions, but imagine how pretty the contrast of the seams with the face of the boards will be!

I agree. I tried using an orbiter sander and putting it on its edge but you are right, not pleasant plus it cannot get down into the narrower cracks.

I wouldn't mess with removal. I'd just redo the face of the boards and let the seams be what they are.

Your only other real choice is to use a new stain that matches the stuff you can't get off.

Pick the lesser of the evils.

Why not try a strong paint remover. Just smear it on and wait a couple hours and smear it off. Works with paint and should remove stain. A little steel wool to rub would be even more effective. Wear solvent proof gloves.

Oscillating tool with a sanding pad attachment for the wide gaps.

Emory cloth for the tight ones if you can get under the deck and must work alone. Stick the cloth down between the cracks and then back up through another (down one side of the board and up through on the other side) then pull the cloth back and forth as you move along the board. If you have a helper. They can pull down while you pull back up working along the edge of the board.

This post was edited by hippy on Sun, Nov 9, 14 at 13:17

Thanks for the suggestions. I tried, repeatedly with stain remover, but with no luck.

Oscillating tool could work, depending on the width of that attachment. I tried an attachment to my drill but it chewed up the wood too much.

If you want to sand, I once went to a tool rental place and got an orbital, flat floor sander. The paper and fiber pads it used were pretty expensive, but I did a 12X70 deck in a day. I would not consider a drum floor sander. Too easy to scallop.

Nerdy
He/she is wants to remove the stain on the sides of the boards between the cracks. Not an easy task without pulling the decking up so that you can easily get to the edges.

Then I still think they should use a powerful PAINT remover not stain remover. A good paint remover will soften many layers of paint of any type. The chemicals are strong enough to burn skin so neoprene rubber gloves are needed. They have those at Lowes and I believe the remover too, if government regulations still let it be sold. I have used many brands, mostly gels that you apply then use steel wool or scrapers to remove paint. Stain should be duck soup.