I just finished putting laminate flooring on our stairs and used 3/8" birch plywood for the stair risers. I have quite a bit left over and thought I could use to build the walls of some scratch buildings I hope to get started on. What is your opinion about this? Will it hold up in the weather? During really inclement weather I would bring the buildings inside for added protection. But we typically have mild winters and hot summers here in the Central Valley of California.

I also thought of using for shelving to put the engines and rolling stock on attached to the garage walls.

Thanks,

Richard

Here’s a reasonable discussion regarding Baltic birch plywood. While I have used it for cabinet building, I would never use it outside for something that I cared about, no matter how well I protected it.

There are also discussions regarding cheap Chinese versions of the product so I would be especially wary if it is purchased from one of the big box retailers.

Why not just make a very simple structure, finish it and then treat it as you would if it was one that you spent considerable effort on? That might give you some real world experience for your environment and climate.

Good luck and let use know your experiences.

Thanks Mark for the link. Very informative!! And I like the idea of creating a simple structure for testing purposes.

Richard

I’d add that you should ensure to use the same construction methods, fasteners, glues and finishes that you expect use when you make the “real” structures. This will ensure that your test is as close as possible of an actual structure.

While I have never made an outdoor model structure out of MDO, I’ve always thought that it might be a reasonable material of choice. I have used it in a couple of outdoor projects, such as bins for a potting bench and it has held up pretty much intact over 10 years. While the bench is outside against a building with little overhang the bins aren’t exposed to direct sun but they do get wet during the winters. They were just painted with high quality exterior primer and paint. I might just make something for a friend who has an outdoor RR but I don’t currently need another project; it’s on the “round to it” list.

Good luck.

In the Construction Industry we use MDO and HDO Plywood for concrete forms. We can usually get 10+ reuses of the MDO (pouring concrete into the MDO forms) and up to 50 reuses for the HDO. I have used 3/8" MDO, but have not seen anything thinner. Be sure to seal the edges after cutting so that it does not de-laminate when left out in the weather. MDO has a nice smooth surface that can be painted easily. Keep us posted if you are able to find MDO in thinner than 3/8 inch.

I would treat both inside and out and everywhere. The thing is the glue. Its not waterpoof on interior grade plywood so it can delaminate. I like the test idea and then just seal the heck out of it.

Has anyone used poly based fiberglass resin to seal wood then paint? I have often wondered.

Best ply to use outside is Aviation Grade ply. Darn expensive…but still needs treatment against inclement weather.

Devon Sinsley said:

I would treat both inside and out and everywhere. The thing is the glue. Its not waterpoof on interior grade plywood so it can delaminate. I like the test idea and then just seal the heck out of it.

Has anyone used poly based fiberglass resin to seal wood then paint? I have often wondered.

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There used to be (years ago) a bottled 2 part 1:1 liquid used to coat coffee tables after staining, called FURNIGLASS in the UK.

I reckon it was fibreglass resin. Tough as old boots. Similarly there is also some stuff now available sold to pour or brush on to rotten wood that hardens it. Fibreglass resin??

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No resin (sic) it should not work and it can be thinned.

The stuff you pour onto rotten wood is an expoy resin I believe not poly. Not that it matters. I am sure somerhing like that would work as well. Many of those products are not UV stable so I would be careful in clear coating but as a base to seal wood then painting over I would think would seal up any plywood structure and poly glass resin is fairly cheap.