Q&A for How to Preserve Wood

So there are several options depending on the look and durability you want. A simple water-based option is an acrylic sealer, which works like varnish. You can brush it on, and it’ll dry clear, giving a matte or glossy finish based on your preference. Acrylic-based sealers are very easy to apply and are fast-drying. If you prefer something more heavy-duty, consider using epoxy. This is an oil-based solution that you can pour over the wood. Epoxy dries to a super hard, glossy finish, which adds a high level of protection. However, epoxy could be yellowish if it’s in a room with low light over time. If you want a straightforward and practical approach, acrylic sealers from craft stores work well, especially for smaller projects. Just brush on a few coats, let it dry, and you’re set!

Rotting wood likely needs to be replaced as it can become both unhealthy and unsafe.

Brush raw linseed oil onto planks, You should also use a mixture of used engine oil and diesel, but horses sometimes like to chew the planks, so if they will chew on it, don't use the oil.

In my opinion, wax is the ultimate preserver. There are waxes that are meant for this very purpose. Another way is to use candle wax--you can buy blocks of carnauba or soy wax. Carefully use a heat gun (wax does catch fire!) to melt the wax, and rub it in using a cloth.

Soak the bark in epoxy prior to putting any sort of top layer or sealer on the wood itself. To really preserve the entire piece, it's important to seal all of the pores in the wood to keep it from drying out or soaking up spills. A product like Bar Top (another epoxy that is poured on counter tops in bars and restaurants) will create a thick (and very noticeable) clear top layer that is waterproof as well as chemical- and abrasive-resistant - it stands up very well to hard use, and you'd still see the wood grain through it.

Buy a wood preserver, or a varnish works well, too. If you don't have these around, you can mix 1 liter of linseed oil to 25 g of beeswax to make your own wood preserver.

Cover them with polyurethane to make it hard and protect it from the elements.

Well there isn't much to salvage, in truth it's just best to get rid of them.