How do I stop pine timber boards weeping resin?

[Skatelea]

We recently replaced the pine timber boards on the flooring of our deck. We didn’t realise you need to wait before painting. It is now weeping a thick sticky resin out of all the knot holes. We tried to clean it off with turpentine then sanded it back but the resin just came back. Any tips on what we can do to fix this?

[MitchellMc]

Welcome to the Bunnings Workshop community @Skatelea. It's wonderful to have you join us, and many thanks for your question about preventing Pine knots from oozing sap.

It might be an idea to allow the timber a couple of weeks to continue expelling the excess sap. Remove it periodically with turps and sand back the surface. You can then apply a couple of coats of Zinsser 946ml B-I-N Primer Sealer Stain Killer as a spot undercoat. One of its uses is for sealing knots and sap streaks. After that, apply your topcoat. Using an undercoat like this is your best bet in sealing that sap inside the timber. 

If this issue is isolated to one of two boards, you might like to consider removing them and replacing with boards that don't have as many visible knots on the top side.

Please let me know if you have any questions.

Mitchell
 

[Skatelea]

 

 

Thanks for the advice. I wish it was only a couple of boards so we could just replace them but it is every board in the deck! It is going to be a huge job to treat it all. We never imagined that this would be the outcome of replacing the original timber.

[MitchellMc]

Were these boards from Bunnings @Skatelea? If so, I'd be happy to contact the manufacturer to discuss the best steps from here, whether there were any special preparation steps needed before painting, and to find out if this level of resin seepage would be considered normal.

Mitchell

[Skatelea]

Hi Mitchell,  Yes, they were from the Coffs Harbour Bunnings, treated pine decking. The paint was too, Cabot's timber colour self priming deck and exterior paint.

Any help would be really appreciated. Please let me know if you need any more photos or info.

[EricL]

Hello @Skatelea 

Can you please tell me when the pine boards were installed? Generally, pine decking timber will take anywhere from 8 to 12 weeks of seasoning sometimes longer depending on the weather. If the surface is painted too soon the tannins and preservatives pumped into the wood will push the paint right off the surface or will sometime pass right through them. 

However, allow me to make some inquiries for you regarding the pine you've installed. As soon as I have more information, I'll get back to you.

Thanks for your patience.

Eric

[Skatelea]

Hi Eric,

Installed the 9th of Nov.

[EricL]

Hi @Skatelea 

Thanks for that information. I'm afraid the paint was applied too soon and now the tannins are trapped inside timber decking panels. I propose sanding the surface of the panels back to wood and allowing the pine to season some more. I usually suggest using Feast Watson 1L Woodclean to accelerate the process. 

But in this instance, I suggest letting it season properly just to be on the safe side. You'll notice the panels will be ready as they will stop sweating and will constantly remain dry. There will be no more tannins or preservatives leaking out.

If you have any other questions we can help with, please let us know.

Eric

[Skatelea]

Thanks EricL so just checking,  it's normal to install a timber deck, leave it unsealed from the elements for 3 months and not use it all that time because it's covered in patches of sticky resin? 😮

[EricL]

Hi @Skatelea 

Yes, its ok to leave the panels exposed to the elements. The preservatives and tannins will then come out and get washed off in the rain. If you feel that the surface of the panels are a bit sticky, I suggest washing it with water and detergent in combination with a stiff bristle broom. This will temporarily clean the surface of the timber so that it does not feel sticky. But as I mentioned, it needs to be given time to sweat out the tannins and once it stops you can then paint or seal it.

Eric