How to build waterproof timber ramps?

Joey3

I am looking at making some wooden ramps for my science class to pour different liquids down to test viscosity. Every year I make these and they warp which ruins the scientific investigation so wondering how do I make these waterproof so I don't have to continue making them. I am also going to make smaller ramps with different materials on them e.g. fabric, artificial grass etc for my younger students to test friction by running toy cars down them. 

MitchellMc

Hi @Joey3,

It would be best to build the ramps out of something stable, like plywood, rather than solid boards, as plywood is far less prone to warping. To stop water getting into the timber, you’ll need to fully seal the surface. A few coats of polyurethane varnish should do the job. Alternatively, you could use a waterproofing product like Crommelin 1L Exterior Grade Brushable Waterproofer. There is also a sprayable version.

I’m presuming your ramps are simple sloped channels with raised edges to contain the liquid as it flows down. If so, it might be worth thinking beyond timber for durability. There are some ready-made products you could use instead of building from scratch, such as aluminium channel (e.g. Metal Mate 25 × 25 × 1.6mm 3m Aluminium Channel) which is lightweight, rigid, and will never warp, or furring channel (e.g. Siniat 18 × 2400mm 0.42bmt Furring Channel) which is designed for framing but could double as a trough. Another option is plastic downpipe, where you can cut one side off a rectangular section to create a perfectly uniform ramp surface.

These prefabricated channels would save you from repeated rebuilding, are naturally waterproof, and would keep your viscosity experiments consistent year after year. For your friction ramps (fabric, artificial grass, etc.), plywood panels will still be fine, since they’re not being soaked. Just give them a quick seal coat to stop them from absorbing moisture over time.

Please let me know if you have any questions.

Mitchell