Cedar planter tech

[AK_F250]

I made a planter box out of steel and 1/4" t&g cedar and I'd like it to survive more than a couple years. I know a plastic or rubber membrane is an option, but I was also thinking about coating the inside with some sort of epoxy or resin to keep the moisture out of the wood. There are 3 3/4" drain holes in the bottom so it won't be watertight. Am I better off with a 10mil trash bag every season or is there a coating that will work for what I want? The exterior is sloped and has about 6 coats of helmsman spar urethane on it, not sure if it's the right product for the job but I had some left over from another project.

Sorry in advance for the potato photos...

 

[SLOWPOKE693]

DIY truck bed liner?

 

[AK_F250]

DIY truck bed liner?

Damn that's a great idea. I have cans of it that I use for bumpers and sliders, no idea why I didn't think of that.

 

[Add]

Rubberized undercoating.

Go get 2 or 3 cans at Napa and be done

 

[Pt_Ranger_v8]

better make the holes a little bigger if you're going to line them.

Is the inside sloped at all to make water go out instead of sitting on the bottom?

 

[Santa]

Why? It should last 10+ years as is

 

[AK_F250]

better make the holes a little bigger if you're going to line them.

Is the inside sloped at all to make water go out instead of sitting on the bottom?

Yep I cross broke the base

 

[AK_F250]

Why? It should last 10+ years as is

I haven't messed with cedar much other than 5/8 fence and being so thin packed with soil I'm worried it wont last that long. It's a gift for my mom and I don't want a maintenance headache for her. I'm probably over thinking it though.

 

[Santa]

I haven't messed with cedar much other than 5/8 fence and being so thin packed with soil I'm worried it wont last that long. It's a gift for my mom and I don't want a maintenance headache for her. I'm probably over thinking it though.

Probably. But if it's for your mom, coating the inside won't hurt.

Also looks like you're in AK, so I bet things get a little more wear and tear than here in CA. we have 10 year old redwood planter boxes that other than oxidation look new. Granted they are also 2 x 12.

 

[Dethmachinefab]

I'd line it with a drain board membrane. Thats how it's done on the jobs I've been involved with.

 

[Tell_Sackett]

My grandpa made some planters out of redwood probably 25 or 30 years ago for my mom. No lining, no finish and the just started failing a couple years ago. If say don't over think it and you'll be fine.

 

[SomeGuy]

Are you using it for anything edible or just decorative? If you're going to plant anything you will eat, you want to use non-toxic coatings or better to stick to a plastic liner.