Lightening treated wood.

[Poppy]

Hi I’ve bought some nice shiplap wood it’s been treated in a tank. Is meant in general for shed building use.
I’m using it inside in a utility / stable type area.
Because of the treatment it’s darkened considerably and there are some green spots on some of the wood.
I’d like to lighten it up a bit and then use Osmo oil on it to protect.

Any ideas on this ? I’d thought of using oxalic acid maybe but haven’t done this before will it bring it up lighter than is ?

Thanks for any experience and ideas.

 

[Jameshow]

Bleach?

Why not just use as is. You don't want to remove the treatment and adding osmo seems a waste of osmo??

Cheers James

 

[Poppy]

Hi James

Thanks for responding, I'd definitely use the Osmo oil (Polyx) post whatever I do as it will nicely protect the wood and make water repellent as I'm using it in a damp ish area. I find it really gives longevity to the wood and have never had an issue with it.

I hadn't considered to use just bleach as my understanding is that it won't bring the colour of the wood back up, I have tried bleach in the past on a couple of small projects without success and Rustins A and B was recommended to me, however I haven't used that as yet.

I was really wondering if anyone had any experience of using Oxalic Acid themselves and how they'd found the process

 

[AJB Temple]

I use oxalic on untreated oak. I buy it in 10kg tubs in powder form.

It will require a miracle to lighten your tanalised shiplap without sanding down past the impregnated surface. Oxalic acid will not do it.

 

[Poppy]

Ah ok I did wonder if that might be the case Never mind I might rethink - thanks for your input AJB Temple

 

[Poppy]

Well I've tried some bar keepers friend which has a small amount of Oxalic acid in and it's made a good difference on the wood. SO I've ordered some O Acid and will try it properly at the weekend.

Photos will follow - phone not working at mo!

 

[Krome10]

Looking forward to seeing your photos and how things progress for you. Good luck

 

[Poppy]

Thanks I have taken a few photos of the lightening process it was a considerable success - I’m really pleased.
You can see from the photos the wood was pretty dark, now it’s a golden blonde. Really nice, not yet oiled to finish as I will sand a little bit first. But I’m very pleased with the results

 

[mrpercysnodgrass]

Take great care with the finishing process. Rinse the Oxalic off with plenty of fresh water, if you need to sand it after this make sure you have a good mask, allow the dust to settle then vacuum before proceeding with any other work.

 

[Poppy]

Yes thanks I worked with a mask at all times. Washed off let dry then neutralised with vinegar & water. Only had a little sanding to do and then oiled it’s looking and smelling good