Where is all this dust in my finish coming from?!

[Linnea Lahlum]

I am mystified. After a very light sanding with 400 grit, wiping down with a cloth, then using a can of pressurized air to dust off, I left the room for several hours so it would not be floating around. Then came back with a tack cloth right before finishing.

I am using oil based poly diluted 30% with mineral spirits,which I have successfully done many times before to minimize the amount of dust that would fall on a piece while the layer was drying. Fresh poly, fresh mineral spirits.

3 coats was the plan. But at this rate my final coat will have so much dust in it I know I will be unhappy with it.

But even right after applying, there is so much visible dust I might as well have shaken a rag over it.

I tried taking a photo, but it did not come across.

Ideas come to mind:

I am working in the same basement room as many times before. This is my basement and it would be impossible to make it dust-free. It is the furnace room and it is winter. But I am turning off the furnace right before finishing, and leaving it off til it sets. Avoid scuffing the floor, shaking anything. I also leave the room as soon as I finish and shut the door.

I am NOT using a fresh brand new brush for each coat. Should I be? The brush is washed out with mineral spirits after each coat, then left to dry.

Should I sand and finish in 2 separate rooms? Any other room I can use for finishing is carpeted. I can protect the carpet, but I figured any carpeted room will kick up just as much dust as I walk across.

Should I wipe on the finish? What would I use, that would not have plenty of dust in it to begin with? I have never wiped before, just brushed, and thinly with the dilution of 30% as above, or 50%.

Dilute more?

I would appreciate your help. Thanks.

[Andy Giddings]

Can't help with where the dust is coming from but wiping oil based is a lot easier than brushing IMO. I use General Finishes Arm R Seal and wipe it on with the blue disposable shop towels, never had a problem with dust but its not normally an issue in my workspace for any finish, fortunately. I would also vacuum the dust off rather than using air, or just use tack cloth

[Prashun Patel]

Like Andy, I prefer to wipe on. However, I brush occasionally in my dusty basement with a re-used brush that is not top of the line. The results are usually good to great. The fact that you have done it successfully many times before leads me to think there's something special about this project.

Are you certain it is dust settling on the surface and not debris in your brush? Are you also certain the problem is not contamination on the surface causing the finish to ripple and bubble? It is definitely dust nibs, right?

[Robert Engel]

Its probably coming from above. If you're in a basement there's movement as people walk on the floor.

Try stapling some plastic sheeting tot he bottom of the floor joists above your finishing area.

[Anthony Holohan]

You could try making a dust free area by hanging slightly damp sheets around your work and boxing it in. This will attract and trap most of the dust out of the immediate atmosphere.

If I'm French polishing a piece of furniture to a piano-finish standard, I still use this simple method I learned many years ago.