Floor air return grates

[HarmsWay]

That's stronger and much nicer visually than any commercial ones I've seen.

I attached the outer frame (which has a 3/4" x 1/4" rabbet to keep it from sliding around in the hole) to the grid with splines and glue. The frame itself is mortise-and-tenon. The grid pieces are 1/2" x 3/4" (the 3/4" dimension is vertical). The opening are about 3/4" square.

And yeah, I can stand on it (160 lbs), though it does flex slightly. I wouldn't place a piece of furniture on top of it, but walking across it doesn't seem to be a problem. The many, many half-lap joints seem to make it pretty strong.

[gerti]

Great idea, I need to make some of those. Sounds like a lot of work though :-(

[cobob]

Sanding & Finishing had to have been a tedious nightmare. I assume you sprayed it lightly & repeatedly?? It looks 'grate' though. You do 'grate' work. Hope my rambling isn't too 'grateing'.

[pecker]

It's a shame you didn't have some of the original flooring to make these with. It might have been interesting to construct it in such a way that the frame blended in with the floor. The "horizontal" portions of the frame could have been assembled sort of "butcher block" style to have the lines in the floor replicated in the lines of the frame.

Regardless, good job!

[JR]

Beautful job! I'm surprised you don't like working with oak. You sure did a good job with it.

I wonder if you considered any different techniques for construction? For instance an alternative might have been to use a single glue-up of solid wood, then run alternating routed grooves on each side. I suppose you probably thought of this and a dozen other ideas, but I was just wondering. LOML wants a solution for the return grate in our house, so this could be part of my future.

Congratulations on a job well done.

JR

[jlm]

I thought about the solid wood technique (kind of like cutting waffle fries!), but in the end I figured that a hunk of wood that big would cost a lot more, and was a little worried about making a single mistake and ruining the whole piece. Also, I wasn't sure how a big slab like that would react once you started cutting slots out of it - would it warp or twist, etc... In the end, I figured this was the safest and least expensive way to go.

As for my dislike of working with oak, there are two things I don't like about it: the smell of cut oak is kind of unpleasant to me, and the splintering when routing is annoying. I love the way quartersawn white oak looks, but this project was just plain ol' red oak, which I don't think is anyone's favorite wood...

As for the original flooring, that would have been a cool way to go. Not really an option, though, since the house is 80 years old, and those are the original floors. When I refinished them, I went through a LOT of sandpaper. Those old floorboards are harder than rock! There were a couple of places where I had to cut off old nails that were sticking up because I couldn't get them to pull out, and couldn't hammer them further in, either.

[newood2]

Nobody does it better. And those unseen flaws you talk about are secret marks of ownership. A beauty.

[mschrank]

I need to make a couple of these, and I'm hoping you can give a bit of insight. I'm not sure how I'm going to go about applying the finish. Did you fully assemble the unit and then stain/varnish? Seems like it would be really hard getting into all those corners, and it would be hard to keep the interior parts of the slats smooth between coats (if they are left rough, I think they would be a real dust trap). But if you apply finish before assembly, how would you keep stain/varnish off of the glue-up points?

How did you cut the half-laps? Did you use a TS with a dado blade, or did you use a router? I'm thinking I'll use the TS and set it up similar to the way I would for cutting box joints.

You did a really great job, and I'm hoping I can make mine look as good. I know what you mean about the expense of buying them pre-made...I need two relatively large ones and they would put me out close to $500

[jlm]

I used a router to make them, but the procedure would be basically the same on the table saw. I used planks that were about 6" wide, and cut them to a little longer than what I would need to make them easier to handle. Then I cut evenly-spaced grooves across the width of the planks (perpendicular to the long dimension of the board) with a router (I made an auxilliary base out of plywood that had a "key" to fit in the previous groove - very similar to the idea behind finger joints). The depth of the grooves are exactly half the board's thickness. Once I had all the boards dado'ed, I ripped them into strips on the table saw exactly the width of the grooves, and they snapped together pretty easily.

I did test this procedure with some pine scrap first to make sure I had it all figured out in my head and that it would produce good-fitting joints. I used a router because my dado blades were in another state at the time, but the procedure would be pretty much the same with that method.

Once I had the grid section all glued up, I cleaned up the edges and used it to measure for the frame. The frame parts are mortise-and-tenoned together and joined to the grid with splines. The frame joinery is very similar to a raised-panel cabinet door - the pieces have a groove (for the spline) cut all the way down the length, and the tenons fit into that groove.

Once the whole thing was all glued together, I ran the whole assembly across the table saw vertically (against a tall auxiliary fence - like making a raised panel) to cut the angled edges and the rabbet on the underside that keeps it from sliding around in the vent. I suppose you could cut those two features before the glue-up, but I wasn't sure what kind of edge treatment I was going to use until the whole thing was glued up. You could also use a roundover or chamfer bit in a router if you wanted a blunter look, I guess.

I assembled the whole thing before finishing. You could mask off the glue joints and pre-finish, but there are a LOT of glue joints...

For finishing, I used wipe-on poly for the first two coats (easier to get into the nooks and crannies without drips) and sprayed the last two coats. The last two coats I didn't worry too much about getting into the holes, I was more concerned about putting a heavier film finish on the top surface, since it's likely to get much more abuse than the vertical surfaces inside the holes. It came out good - at least as good as the finish on the floor itself, which was basically what I was hoping for. I had to keep reminding myself that it's not fine furniture, it's something people will be walking on!

Let me know if you'd like more photos or more detail on these. I looked around considerably before starting and couldn't find any plans or ideas, so I know how it feels to be flying blind on this particular project!

[mschrank]

Great detailed write-up! Thanks!

I'll hopefully get started on mine this weekend and post up some pics when they're done.