Steel Wool and Water-based Poly

[Matt O'Driscoll]

First time posting, and I'm hoping you can help me fix this before it becomes a problem...

I'm building a king size bed made from Ash and Walnut.

For finishing the Ash, I selected MinWax's "Water-based oil-modified polyurethane".
For finishing the Walnut, I selected BLO with a Shellac top-coat.

I have started the finishing process prior to assembly since the Ash and Walnut are receiving different finishing techniques.

While I researched and tested many finishes before selecting the water-based Poly, I neglected to research the Do's and Don'ts for water-based Poly. I sanded the Ash with 180 grit sandpaper, wiped off the dust with a damp towel, and then applied the first coat of Water-based Poly. After letting let it dry, I then started using #0000 Steel Wool to sand out the first coat (my mistake). I only got through about half the pieces before abandoning the steel wool due to the mess and switched to 600 grit wet-dry sandpaper. Later, as I was reading on the web, I learned that using Steel Wool on Water-based Poly is a No-No due to potential for rust. (makes sense...)

I'm hoping I am OK here since the first coat of poly was down before I used any steel wool, which means it won't be caught in the wood grain/fibers; however, I thought I'd ask here before I moved on to the second coat.

My Question:
Is there a way to positively remove all the Steel Wool dust before I apply the second coat of Water-based Poly? A rag soaked in something tacky, or maybe a magnet?
I'm willing to use something that inadvertently strips the first coat of poly, so long as it doesn't prevent a re-coat of water-based poly to adhere. Acetone?

I'm hoping there is a way to remove all traces of the steel wool so that I don't have any black oxidation spots on the wood (rust).

Thanks for any help you can provide.

Matt O'Driscoll
Barboursville, VA

[scott vroom]

Assuming the initial coat of poly filled the pores, I think a quick wipe down with a damp cloth would remove any residual steel wool fibers.

I typically sand between poly coats with 220 or 320 grit. No need for 600 grit...the purpose of sanding between poly coats is to knock down any bumps and rough up the surface for the next coat.

[Rich Engelhardt]

You also need to use some type of detergent wash to remove the oil deposit the steel wool left.
Steel wool is loaded with oil to keep it from rusting.

I'd avoid a solvent since that may leave an oily deposit of it's own.


Acetone?
Nooooo!!!

Much too sharp a solvent. It'll tear up the WB poly something fierce.

[Matt O'Driscoll]

Thanks for the quick replies!
I'll wipe off with a damp cloth moistened with a mixture of water and Dawn dish detergent to remove any oils left behind by the steel wool.
I'll also lower my grit count for between-coat sanding. I have a couple of those 3M foam pads in 320 grit that should work well.

Appreciate the help!
Matt

[Howard Acheson]

>>>> hich means it won't be caught in the wood grain/fibers;

The steel wool shed shards of metal as you use it. These shards end up getting embedded into the finish you are abrading. They may also get into the underlying wood if you are too aggressive and sand-thru the finish film. Any moisture that remains in the finish you are abrading will cause the shards to rust.

Steel wool is not good to use for between coat abrading. One thing you want to do with between coat abrading is to flatten the finish. Steel wool, or non-woven abrasion pads (Scotchbrite) ride up and down over the uneven surface without flattening it. So, if you have Non-flat surface (rounded etc) use a non-woven pad which will not shed rustable shards or use 320 sandpaper on a sanding block for flat surfaces.

To remove any existing finish that may contain rustable shards use a chemical paint stripper containing methylene chloride.