Thread: Suitability of CD plywood?

is that because the glue isn't waterproof?

Yes. It will fall apart fairly quickly unless you seal it very well, especially the edges. My kids' cubby house is made from it and I have painted it with water-based acrylic and it has lasted OK. The bits that I didn't paint quick enough had started to de-laminate.

Form work ply will last a lot longer or you could buy marine ply but if I was making it, I would use hardwood decking.

You're right of course. I have mental images of the edges all curling up. I was hoping for an easy fix.

I can make the whole thing out of decking, including the tapered 'joists'. It will just require a little more dedication on my part.

Well, keep in mind that boats are often made from ply, so it's not entirely infeasible. But I think by the time you mess about with sealers etc, you could make something suitable and better looking out of decking. If you get the grooved stuff you can put the grooves up to give you more traction.

If you look around, you might even be able to source some off-cuts, since you probably only need 900mm long. I pulled a stack of them out of the neighbour's skip when they had a new deck built.

Most CD ply sold in Australia has a waterproof bond - Resorcinol - its the black/red coloured stuff - also called A or AA bond, which is different to the ply grading, the other common glue is Urea-Formaldehyde which is not considered waterproof, and is a 'C' bond - most US ply is 'C' bond by Australian standards. However the plantation grown pine they make the laminations from is cr@p.

One other possibility is to ask around companies that do concrete form work - do you best 'I'm feeble' act - and see if they will rip a sheet of formply to size for you or have some useful offcuts. Its pricey, heavy, waterproof, is roughly BB grade on the faces & has a plastic laminated face both sides & used to be made with hardwood laminations but I think some is now softwood/pine.

That would be so much simpler than me stuffing around with little tapered joists and bits of treated pine. It's such a paltry little ramp that it annoys me having to think about constructing something.

I'll look into that form ply (I've seen sheets of it somewhere; black in colour IIRC). Where do the road authorities get their green-stained (presumably H4 treated) ply that the new freeway walls are made of? An off-cut of that would be suitable too.

bunnies had some formply a few weeks ago

What part of Melbourne are you in?

There is a reasonable chance I will be in Melbourne with my ute early next week if you are stuck and if you don't live too far out of my way.

If you do end up using formply you'll need to paint it with some non-skid deck paint as it's extemely slippery. Don't want to end up rolling or flipping your wheel chair.

Mick

Originally Posted by Wood Borer

What part of Melbourne are you in?

There is a reasonable chance I will be in Melbourne with my ute early next week if you are stuck and if you don't live too far out of my way.

Thank you for the exceedingly generous offer, but I'm well and truly not on the route between Tolmie and Melbourne. What's more, I can't justify the cost of a sheet of formply for my piddling little ramp.

Having said that, if you're touring around Melbourne's East with time on your hands, drop me a PM and come on over for a visit.

Originally Posted by journeyman Mick

If you do end up using formply you'll need to paint it with some non-skid deck paint as it's extemely slippery. Don't want to end up rolling or flipping your wheel chair.

Mick

If I break, I'll mend; I would be more concerned about my precious bandsaw or thicknesser getting away from me on the ramp! But thanks for the advice nonetheless!

I built a ramp in the form of a torsion box, two sheets of 3 ply and an internal frame about 30mm deep. It was strong enough to take the weight of a mobility scooter which weighs a whole lot more than a wheel chair. it also had the advantage of being very light.

That sounds like a good practical solution.

The ramp I'm considering is so small that it's really not worth putting that much though into. The slab that my new shed sits on is 110mm thick and the upper surface is 70mm above the surrounding paving.

I've mounted my bandsaw and thicknesser on 4" castors so I can wheel them out when working with longer pieces of timber. The 70mm step down is proving more difficult to overcome than if it was a 700mm drop. At least if it were a larger drop I could build something more substantial.

I think I'll just use a pre-cut (900 x 600 x 19) piece of CD ply from Bunny's and seal it as best I can. If it lasts a couple of years, then fine. Who knows, my ashes may be scatered to the four winds by then.