Anywhere you'd recommend I buy from? West Marine sells a 48"x54"x1/2" for $359. I know that wouldn't cover the whole rack.
Where are you located now? U.S. Plastics has U/V stabilized, textured sheet. Pretty sure that's where I bought that piece. I have another sheet, but shipping it would be more expensive from me than it would someone who makes a business of shipping the stuff whole.
I think they're branding the stabilized sheet "Seaboard". Doesn't really matter what it's called unless it gets you two finished edges.
I personally just cut a piece for the rear and one for the front. I didn't want to have a giant, unbroken piece up there. You could do it, as this stuff can be shaped with a heat gun, but that's a lot of work and one hell of a wing.
Ive tried to break the HDPE and even folding it 180 degrees back on itself and I still cant break it or crack. Again thats 1/8". Im sure 1/4" would be more than enough. I bought mine from Piedmont Plastics. They have a warehouse down the road here in Raleigh and had 40-50 sheets in stock. They even will do straight cuts for free. They had 2 different kinds of HDPE. Cant remember the differences, but I went with the cheaper of the two. I had no issues cutting or drilling it either. Just used a jigsaw with a metal cutting blade and low speeds. Regular drill bits worked fine, and so did the countersink bits. It can be sanded and is chemical and paint resistant. Thats why I had to use screws vs adhesive. Google Piedmont plastics. They have locations around the country.
Jigsaws are about the best way to get through that stuff, but not everyone can keep them straight easily. You'll want some butch blades to ensure they don't just start drunkenly scalloping their way down the line where you can't see it happening. The Bosch units usually have enough meat in them.
HDPE is tough stuff. That's why it's used for wheel well liners and milk jugs. Hell, if you laminate it right it can help stop a bullet, but it will indeed break if it's pushed. It "work hardens" in it's own way, and becomes more sensitive after years of exposure and in cold temperatures. It's better than plywood, of course, but you can indeed crack it if the right conditions are met.
It won't tear or split from just stepping on it within it's temperature range, but it's a touch slippery. Too much flex in the rain, on something that's already a bit slick, can add up to an injury without a fun story to go with it eventually. It's not hard to walk on, but it's not chicken coop or plywood, either. That same slick factor both helps load and unload cargo, and yet makes strap positioning more important for retention.
It's a give and take.
Of course, nothing is going to beat that clean look. There are no practicality concerns, in the end. The weight won't be a problem up there, it's not too slippery to be safe (people walk on it in boats all the time), and it's got a very wide temperature range. Cut it right, and it'll absolutely out-last your interest in reaching up that high; and it'll always look new when wiped down.
As for breaking:
There's one small section I had to cut off the rack when a piece split off. I tried to fly too close to the sun when fitting that, and a stress riser caused a split when the sun caused it to expand on a cold day in the rear corner where the light tab is. Rack got smaller, sheet got bigger, and that one corner got stuck right where I thought it would; the one place that had nowhere to go. That little piece bound up and snapped right off like an ice cream bar.
Oh, well. It was worth a try. The other option was to cut it exactly where it snapped, anyway. No harm done.
It was a "Why not?" feature; about a two inch width that I figured I'd leave for aesthetics if it would stay. Didn't surprise me. The piece wasn't required, but it does illustrate the sort of conditions under which HDPE will break. A lot has to be happening at once at the right temperature.
It's certainly resistant to most chemicals. That can be a problem, at times. It's very difficult to get anything to stick to it. So far as I am aware, there is still only one product out there that will actually stick it to anything else. 3M makes it, and it's just not priced or packaged for small jobs.
Even Dynamat Extreme comes right off with no residue, and if you've ever got that soft butyl stuck on anything else in the universe shy of a Teflon frying pan, you know how impressive that is.
Truck bed liners, wheel wells, milk jugs, cutting boards, coolers, rotary molded cases... HDPE is chosen for those uses for solid reasons, but notice that every last one of them avoids sharp corners and leaves room to expand and contract.
Cheers,
Kennith
