Salt/white residue shows up after 2 months? HUH?

[B.A. 14]

Hey everybody- another problem has occurred for the A-Team.

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This project was a rescue [iN APRIL] for a homeowner that moved in and found the deck in a bad way (coatings wise). there were a few different types of stain that were on it, one of them definitely being an acrylic (possibly even sikkens dek).

We stripped it twice and got down to 5%-8% residual stain (mostly on the rails and verticals)

Sanded.

Our stain selection was A/C redwood semi. Looked good, customer happy.

Customer called a couple of days ago and sent me the pic you see above.

I know we neutralized and rinsed the hell outta this deck so ....what gives?

Also sidenote: Best way to remove stain drops from pavers after a week or two?

[seymore 90]

Looks like sap that will crystallize from the heat wipe it down with laquer thinner and touch it up. I've heard oxalic will also crystallize if not rinsed also but it's rare from what I know.

[seymore 90]

Try a strong solvent or deck stripper on the stain and it might be easier to drop in another paver than to clean it.

[Beth n Rod 1,279]

I agree, but it could be two things:

1. lack of rinsing the ox.

2. pressure treatment leaching up out of the wood. If it had a film forming coating on it before, this could be the case, since the wood is "breathing".

If it is ox, you can wipe it up with a damp rag. Be careful, you can take A/C off with just about anything on wood.

On the pavers, use a deck stripper or strong degreaser....BUT....don't to a partial paver. Do an entire paver, in case the color is effected, it will be uniform.

Beth