Despite having built our ninja course 2 years ago, we finally got around to painting the wood with a wood sealer. We happened to have two different types of this product – Thompson’s WaterSeal and Olympic WaterGuard. We didn’t have enough of either kind so we used both. This also was quite an involved project so I decided to do a little write up and comparison.
What And Why
Even though we built the ninja course out of pressure treated wood… anyone who’s worked with lumber before knows that these days pressure treated lumber just doesn’t hold up like it used to. The pressure treating goes only a millimetre or so into the wood. And while it helps – especially with insects – it just isn’t enough to withstand the harsh damage of rain, snow, sun, bugs, temperature swings and more.
We really should have done this the first year we built it – when I climbed up on top this week I was quite dismayed to find that the top sides of all the beams are grey and sun damaged already. Well, better late than never, so we made this into a family weekend project. Our 3 sons helped us with whatever they could reach, and refilling cups of sealant, taking off and putting back on the attachments, etc. The weather was perfect for this, warm but not too hot, sunny and with a couple of clear days coming after for plenty of drying time.
How
Wood sealant, even the oil based kind, we found is not thick enough to really be ‘held’ by a normal paint brush. And the sponge brushes tended to shred quickly on the rough wood. We ended up using a paint roller for large sections and flannel rags for everything else. It was a very sloppy, messy job.
It took about 2, 1-gallon jugs of sealant (we used 2 kinds), trying to be generous with the application but avoiding directly coating attachments like hooks and climbing holds.
We set up some scaffolding and ladders. It took us about 4-5 hours total (the kids abandoned us after they finished the lower parts of the poles so it was just two adults doing the remaining 3/4).
Sealant Comparison
We started with a gallon can of Thompson’s WaterSeal. This is a clear product that is oil based and doesn’t stink. We started with this product so most of the upper portions of the ninja course used it. After that ran out we switched to a jug of Olympic WaterGuard. At the time I bought it I didn’t know this would be such a different product. But it was. Water based and milky-white. It’s much thinner and doesn’t leave behind a slight shine like the WaterSeal does.
We liked the Thompson’s WaterSeal much, much more. It was thicker and felt like it would be more protective. It gave the wood a nice slightly shiny glow after it dried. And it was easy to see where you had and had not applied because of this change in look. The WaterGuard was too watery, it was making a huge mess, running down our arms and dripping down the beams. Despite being milky as you wipe it on, it soaks in fast and then it’s very hard almost impossible to tell which areas you’ve missed. After it dried, it didn’t look like we had done any thing at all.
Both products claim to protect from water and UV sun damage. Both claim to last for a long time and be low VOC (not stinky). I don’t have any feedback on these claims or their relative effectiveness, but we preferred the Thompson’s WaterSeal drastically more just based on how it went on and how it looked after. We’ll be using that in the future.
Conclusion
We plan to re-seal the ninja course every 2 years. Probably painting the wood would provide even better protection, but we like the look of wood much better and don’t want paint rubbing off the wood onto clothes and skin (the cheese walls I made and painted yellow, unfortunately turn everything they touch yellow- and I bought excellent paint).
We preferred Thompson’s WaterSeal over Olympic WaterGuard by a significant margin. The price is comparable for both of them (about $50 CAD / gallon jug).
I think the key is to make sure you use SOME kind of wood sealant on your ninja course and reapply regularly. Don’t let the sun and weather destroy your awesome project.