White film on wood deck

I just finished a wooden deck an hour ago for my brother. I DS 12.5% I had a half OZ of Elemonator per gal. and half OZ of Gain Per gal. As the deck was drying there was a white film/residue left behind. What could have caused this and how can I get rid of it?

We’re you just rinsing dirt off or doing a throughout cleaning? Downstreaming is not strong enough to do decks. I use my chemical pump and spray 2-4% on it. Rinse with 40 degree tip at 700-800 psi and repeat.

Some guys will even suggest that 700 psi is too high but I’ve never fitted wood at that psi.

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Hey Chris:
I was trying to give it a good cleaning and brighten it up a bit. Its never been water proofed or stained. Its about 3 years old.

I tried a little pressure with the white tip in a small area and the white film comes off but I wanted to get some opinions her before proceeding tomorrow.

Gain does not belong in any mix that is sprayed on the exterior of a house or decks

Use a pump sprayer or chemical pump and spray about 3% on it. Let dwell and rinse with a wide angle fan tip at no more than 800psi. if you see it furring either spray further away or move up a tip and down psi

What detergent should I be using if any?

Just a little eleminator.

OK sounds good! Thanks

Make sure that deck doesn’t dry out when you apply the mix. If it dries out it’s bad news bears working double time

The way @SchertzServicesLLC explained it is the only way I’ve had any luck doing decks.

Don’t forget to use oxalic after rinsing the SH thoroughly. It makes quite the difference.


Depends on what your using my 4/4 with straight SH will clean one in a hurry.

Did a nasty epee deck with it too. Only deck I’ve had to pull out the 12v for was a trex composite that hadn’t been washed for a decade.


I like using a adjustable wand for doing wood to find the sweet spot on pressure. Northern tool sells them if you have one close by. Turn the pressure all the way down and ease it on till you see it start taking off the “film”. I use a white tip and usaully do 2 boards at a time over lapping the previous boad as a go along.


Two things it can be…algae that is partially dead and didn’t come off while rinsing…or mill glaze…google it. Don’t worry, wait a few days and you won’t notice it