fence panel knots and cracks

Just replace the wood. You can really fill it. If the wood is falling a part it's not treated or low quality. Has to be replaced

Hi, you can buy knotting. It's a treatment for knots. You simply brush it over the knots and it seals them to stop the sap from seeping out. After brushing away the dust simply prime it, and double undercoat it if you want a finish of paint on the timbers. Next, you can fill the knots and other imperfections with a two part filler with hardener and sand off. Finally, add gloss to finish. If you are looking for a natural wood finish, simply apply the knotting to treat the sap. *Update about your painted panels.* You can scrape off or sand down those areas. Apply the knotting and touch up with paint. If you have use stain, just sand the areas where the imperfections are and simply apply knotting and retouch with stain. Good luck with your project!

My suggestion would be to replace as and where is necessary, treatments and solutions will work but for long term I’m not sure how long before you would need to replace anyway, hope this helps.

Treatments are ok for the short term, a temporary fix, a bit like an exhaust bandage on a car, considering they have only been up a while, it has to be a bit of a worry, personally, I would replace them, as soon as you can afford it, but, wood knot filler will work in the interim.