Dark Spots on wood after sodium hydroxide

Im sorry if this has been asked, but i could not find an answer.
I am stripping and staining a cedar fence. The stain was half worn off, but still a large amount on big sections of the fence. I pump sprayed sodium hydroxide, rinsed with white tip, amd post treated with oxalic.
The fence has dried, and there are spots that are alot darker than the rest (predominantly in the spots where there was no old stain). Some portions are perfect. Not sure if it is hydroxide that penetrated the wood or what. I am at a loss amd am trying to avoid an angry customer.

Can you post some pictures?

I will tomorrow. I do not have any handy. I was supposed to stain saturday, bit not sure if I should of the spots are too dark. Customer just said some parts were a different color than others.

You have to be careful with cedar. It’s a little different than your average pressure treated pine.

Just for future reference if you’re going to use the same color stain or, darker, you don’t even have to strip all of the old stain off. You do want to get the loose stuff off though.You just want to test to see if it’s waterborne or oil based so you be sure to apply the same type of stain on it.

You’ll get more help once you post some pictures. You’ll also have more info since right now you’re just going off of what the homeowner is telling you. We’d basically just be guessing since you haven’t even looked at it yet.

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As @marinegrunt said we need pics but off the top of my head if it is the areas that had no stain I would try hitting the spots with oxalic again and see if that doesn’t lighten the dark spots. Where in Texas are you located?

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Ill put some up in about an hour. Im in dallas area

The wood guru @MDA1775 is definitely the one to help guide you on this one.

How dark is the new stain that you’re applying? What brand of stain?

Hard to see the first pic because of the sun coming through the fence but on the one on the driveway where it is brownish at the bottom I am almost guarantee you were holding your wand and pivoting up and down and when you got to the lower section you didn’t maintain the same distance from the fence so you end up with an uneven cleaning and it is always worse on the bottom because we naturally don’t want to bend over that much. I go through this every week with the young man that works for me. It’s also the reason there is so much junk sprayed under the fence.You’re in DFW so a couple of things 1. You can DS a light mix of SH on the parts that are still dark a. wet the wood b. DS and dwell for about 10-15 min 3. pressure rinse with about 1000 psi. 2. Re-stain using Wood Defender in one of the semi-transparent colors. That is an older fence, too old for a transparent stain to look good. It will need the additional pigment. Plan on about 110-120 sq ft per gal.

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No pics no proof…

I already posted them…

On the top pic, something didn’t go right. I’d redo those sections. It would have looked similar when wet. Letting it dry was not going to help it. Should have addressed while there. In the far right section of the fence shown, the middle clean but not the top and bottom.

How did you apply your hydroxide? Guessing with maybe a pump up and you didn’t get an even covering of your solution.

Thank you, I will attempt to do that of the customer ever responds.
I did notice this when I first started the fence, and went over it again and had the same results. The customer has not responded to any of my attempts at communication, and even ignored me when I rang the doorbell today. I saw him look through the door amd walk away so I am waiting to see where this goes.
He wasnt upset at all last I spoke to him, so not sure what the deal is. I hate leaving a job incomplete, but at this point I have wasted time, money and energy on a customer that cannot even acknowledge me. If he will not respond, amd walk off from the door before the job is complete, why should I expect he will not do something similar when it comes time to pay?

I will attempt communication for the next week, but if I have no response, I will take the loss and move on. Not what I want, but what can you do.

Sorry this took such a wild turn, but I have been very patient and communicative. I do my best to be extremely professional and friendly, but there comes a point when you should not waste any more time.

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That’s too bad, can’t stand a customer that does that, fortunately free and far between. A mechanic’s lien may be your only recourse. Good luck.

Has anyone downloaded the pics and zoomed in? The prep on it looks terrible. You were crossing over the runners/stringers going the wrong direction on the grain. Some passes you even stopped before you got to the runner. It all looks just terrible and nothing is going to cover that up unless it’s a solid stain ie acrylic. I’m almost positive he doesn’t want you to continue any type of work. Trust me, I have had customers that get real crazy about wanting the look of a new fence with a old one. I stained for three extremely large fence companies in DFW. I ran 4 trucks and had a crew of 8 and we were booked out almost 2 1/2 months. Paid another handful of guys to prep all the fences for us. Hated every minute of it!

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I sorry I’m late to this but what did you use to try and remove old stain. At what pressure did you wash the fence? Hot or cold water? What concentrate of sh and ox did you use? Did you pre wet the fence? Can you post a before picture?

I ended up speaking to the customer, he was sick and was ignoring everybody. I went and redid the whole fence cleaning today. Turned out much better and even. Ran down to the runners and went with the grain the whole time. Used SH with water and elemonator and it took out the dark areas. Post treated with oxalic.
I learned my lesson on this one… Next prep should go MUCH smoother.
Guy is pretty nice, and wasnt upset at all so I stressed myself out over nothing.

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Once I get more business i will outsource my prepwork. I can see how you hate every minute of it…

Any pictures?

I have a gutter guy now. I need to find a stain/sealer guy. Im getting to where i like to pick and choose what gutters i will do and i dont want to do staining at all anymore.

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