How do you prevent streak in poly?

[TheRic]

A co-working of mine just finished resurfacing a desk. He says that when he puts the last coat on he can see streak marks. He wants the top to look like glass.

He said he tried a foam brush and a fine paint brush. They look fine from a distance, but once you get up close you can see the streaks. Any ideas on how to eliminate this?

Thanks

[Ken Massingale]

My preference is to wipe on. Thin coats with a light touch. I suck at brushing.

[Tom Miller]

When you say "streaks" are you talking "ridges" or are the streaks whitish and otherwise smooth?

Ridges may be caused by trying to brush on a viscous finish too thin, so that you don't get an even coat. Surface tension will keep the ridges from coalescing.

I second Ken's suggestion -- wipe-on poly.

Regards,
Tom

[Mrs. Wallnut]

On the BS boxes that I have done I have been happy with wiping the poly on. Also I have done the light wet sanding paper with some finish on it and then the final coat of just lightly wiping the poly on. I know that is how Mark does most of his finishes also he has used some spray on lacquer and it has turned out good. My next project I think that I am going to try the spray lacquer and see which one I like that best.

[TheRic]

The Streaks are ridges, between the brush strokes.
Maybe trying a thicker coat would work, probably won't hurt.

Is wipe on poly a brand / type? Can it be added to the poly he has? Can you layer it? Does he still sand with 320 grit before he puts it on?

OR

Dose he use a rag to wipe on the poly he has? Same steps as before, sand with 320 grit, wipe clean with tact cloth, etc then wipe on the poly?

[WayneJ]

I would wet sand the top then wipe with mineral siprits. Then use wipe on poly, wet sand between coats. Minwax makes a wipe on poly in pint cans in satin or gloss finish. I like to use gloss for the last coat , when dry I rub it out with 0000 steel wool to look like satin. Let it set up for a week and then wax. I have had great luck doing it this way. 320 is o.k. for wet sanding. An old tee shirt works well for wipe on. HTH
Wayne

[Tom Miller]

What Wayne said....

But, I make my own wipe-on poly, since it's just regular poly thinned with something. I use naptha, some use mineral spirits. It's way cheaper, and I like to vary my mix from 50% poly to 75% poly, depending on the project and which coat I'm on.

I think a good idea is to use clear poly for all undercoats, then finish with satin if that's what you want. Or, as Wayne says, just use 0000 steel wool to tone down the gloss.

I think he'll need to flatten the ridges before continuing.

Regards,
Tom

[Wood_workur]

RUB THE POLY OUT!!! Pick up the most recent copy of American woodworker, or wood magazine, both have articles on properly using poly.