Cedar Siding restain

1

Our home has around 2000 sq ft of cedar siding, that was stained 4-6 yrs ago, not sure what was used as we are the new owners.
I would like to understand what is the best option to remove all existing stain, so we can apply new oil based penetrating stain.

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2

Your best option is to call a professional.

1 Like
3

Lols :slight_smile: thanks, yes ofcourse, that is the best options. Maybe i was not clear, I am looking for DIY options.

What would you reccommend to use to remove the existing coating on the siding. I was thinking of

  1. Potassium hydroxide (what would the maximum concentration per gallon of water)
  2. Some neutrializer (like to know what best that’s available in canada).

Thxs

4

I wouldn’t use more than 12 oz per gallon but start at 8. Neutralize with either Citric or Oxalic acid. @anon37135677 can probably tell you where to get them in Canada.

5

Thanks this helps. Will wait for Max1 to provide some direction on procuring in canada (GTA ).

I had just used the Sansin Wood strip on my deck, sprayed with hand pump, kept it wet for the dwell time of 20 odd minutes and power washed it, worked great, I am waiting for a day to dry and apply their neutralizer. The cost was $60 a gl, so i checked the SDS sheet and found Pottasium Hydroxide as the only chemical, searched Potassium hydroxide and landed on this portal and have been reading through it for the last couple of days, good infromation thanks to you all.

I also learnt of the “donwstream” method so will use that to spray the stripper, will tape of and cover all exposed metal with plastic (not much around anyways).

thxs

6

You won’t be able to downstream the hydroxide as it will dilute it down too much. Let’s say when you mix 12 oz of hydroxide in a gallon of water that puts you at a 10% mixture or so. When you downstream it will mix with the pressure washer water and will drop it down to like 1% or even less. A pump up or 12v is the best way to apply.

If you can’t find potassium hydroxide you can use sodium hydroxide. It’s cheaper and probably easy to find. They both have their place but won’t matter so much for stripping. They do attack grease stains a little different though.

7

Understood, cant use the downstream due to extra dilution.
I take it that an airless sprayer is not an option too even if I flush with water & vineger immediately, after as the stripper is corrosive ? (Dont want to risk damage to the pump.
Will look at the 12V or pump up.

8

I’m afraid I have to agree with @DisplacedTexan on this one. Reason being is that it’s your home and causing irreversible damage would suck. As for oxalic acid, you can get it off of Amazon or a place out of Quebec www.Ardec.ca
Best of luck

9

Thanks Max1 will check Amazon, any idea where i can source potassium h ?

Yes i agree to on the risk and that it would suck if there is irreversible damage, I am willing to take the risk, but would like to mitigate it by getting some sound adivise, and then perfomring the job slowly but correctly, i have the time so no rush. I can try on the rear side which is not visible first and then move to the front.
If you don’t mind can you share what would you as a professional do ? What are the details that i need to be aware ? The stain on the rough swan cedar probably is a oil based stain i can tell should i be evaluating other chemicals ? Sanding is out of question as these are rough swan, i know i will have to be carefull with the pressure washer. Any and all tips suggestions are welcome and yes i have and am reading extensively on this portal.