[bluefoxicy]

1500PSI at 1.3GPM, though hooked up to a kitchen sink.

So I started with a mess...

And it can clean that up...

But in the end, there's still a lot of black stuff left behind, some dark areas, and general dirtiness that I can't even remove at point-blank range with a 0 degree spread!

The pressure washer was capable of damaging the workpiece if used carelessly--I even tore up some of the railing by coming from the wrong direction, against the grain, which lifted and stripped off bits of wood. Not capable of entirely cleaning the workpiece, though.

This was a Greenworks $100 1500PSI 1.3GPM pressure washer, not the most powerful machine I've ever used but seems very sturdy and well made. The fit and finish is excellent, which I hope reflects the overall build quality.

 

[Wandererone]

Had the same problem with terracotta tiles that were stained by a vine.
Ended up mopping with a VERY strong bleach solution that I let sit for an hour or two.
Blasted again and Bingo! 90% of it disappeared.
Worth a try.

 

[joecaption]

Is that mold or old stain your trying to get off?

 

[Fix'n it]

see what it looks like after it is dry.

 

[bluefoxicy]

Is that mold or old stain your trying to get off?

I think mold.

see what it looks like after it is dry.

 

[Thurman]

"1500PSI at 1.3GPM, hooked up to a kitchen sink." You're trying to get 1.3 GPM through a kitchen sink connection. I'd say you have a 3/8" line feeding each of the cold and hot water sides of a faucet. This would not be enough to furnish 1.3 GPM to your unit. Unless-you disconnect your supply line to the sink and tap straight onto a 1/2" feed line. I'd say you are not getting even close to 1500 PSI right at the nozzle of the pressure washer.

 

[bluefoxicy]

Aha. Good point. I'll have to drill the wall and add a hose line fed straight from the 3/4 CPVC feed. Not enough water to drive the unit.

 

[DexterII]

I agree with Thurman; you are not going to get enough water the way that you have it hooked up. But, as you have already witnessed, more volume, and particularly more pressure, is not necessarily the entire answer either, as you have to be careful not to damage the wood, and many of us have seen the sad results of well intended persons attacking a previously good deck with a high pressure washer. And, for some reason that I have never fully understood, pressure washers are the one thing that people expect to clean something all by itself. For example, you don't jack up the pressure to the house and elinminate the use of soap, shampoo, or laundry detergent, right? Nor do you expect to remove the grime form a car or truck by simply using a high pressure rinse. There are a lot of opinions on technique, so it is likely that some will disagree, but I have found Krud Kutter to work well in the injector in my pressure washer. But not all pressure washers have an injector system, and some that do have them don't always work the best, so something as simple as prewashing with **** and Span or a similar product and a stiff brush can provide good results. Will all of the black come off? Hard to say as it may be into the grain, but something to break the tension between the wood and the mold, grime, old stain, or whatever else you may be dealing with will go a long way toward having something that you can stain or paint after it has dried. I always check under the deck as well, to make sure that water is not able to stand there, and that leaves and other bebris is not accumulating, as they will hasten the return of mold and mildew.

 

[Fix'n it]

I think mold.

looks a heck of a lot better than it did. those 2 bottom steps, are those stains or wood grain ?

 

[bluefoxicy]

looks a heck of a lot better than it did. those 2 bottom steps, are those stains or wood grain ?

black crap is staining from rotted mold. The whole thing was coated in a black/green layer that became slick as all hell when wet... doesn't bother me, but is a hazard for anyone whose balance isn't trained. Looked ugly, too.

I'm guessing the material here is wood.

Probably standard pine.

 

[bluefoxicy]

But not all pressure washers have an injector system, and some that do have them don't always work the best, so something as simple as prewashing with **** and Span or a similar product and a stiff brush can provide good results. Will all of the black come off? Hard to say as it may be into the grain, but something to break the tension between the wood and the mold, grime, old stain, or whatever else you may be dealing with will go a long way toward having something that you can stain or paint after it has dried.

I actually used the detergent bottle (a low-pressure attachment that dilutes--assuming 7:1--a detergent into the stream) to spray a 4:1 dilution of Simple Green on the deck first (that's 28:1 overall... recommended dilution for this application is 30:1, so slightly strong).

This pressure washer doesn't inject detergent into the high-pressure stream. It has a soap bottle appropriate for applying detergents to cars, decks, siding, and the like.

Perhaps I should get out the Drill Brush?

 

[CaptRandy]

First off; get the proper feed for the machine.
second; let a cleaning agent do the work and Simple Green is not an acceptable cleaner. Go to a paint store and get some Wolmans Deck Bightener. Mix it up with warm water and apply with a pump up sprayer. Let it dwell for about 10-15 minutes. Then power wash off the mole, mildew and dirt properly. You are trying to kill the mold and mildew not just remove it. Can't get deck brightener get some wood bleach.
Last; NEVER USE ZERO TIP ON WOOD. Not even a 5 degree tip is acceptable; min 15 degrees at least.

 

[Windows on Wash]

+1

Wolmans works pretty well and too aggressive a tip will raise the grain and damage the wood like Capt mentioned. Let the cleaner do the work and not the pressure washer.

 

[pfunkmd]

I have used deck cleaner and it works wonders.