using routing or cutting tools for insetting accoustic ceiling tile edges

[bent]

You know the regular Armstrong, the ones that fit into the track rather than on top of it. I am now cutting the non-inset 2'x4' type to fit all my openings.. I have about 65 tiles total, average about 3'x2' in 4 rooms with not perfect, but simple boundaries. If I could rabbett or straight bit the edge, or use a TS is this possible? They are white, and I could spray the edge if I can make a deent profile. Is this too much hassles/impossible. I am thinking I COULD pencil along the panel as it sits on top like it was meant to stay, then tool it to the T-bar, minus a little for play .

[DT]

I've never done this to ceiling tiles, but I bet a router would chew up on the edges. Couple of cuts with a table saw should do it. You can probably just cut the face the proper depth, and then slice off the waste from the side with a razor knife. In fact, depending on how tough these particular ones are, you might be able to just cut everything with a knife. Draw your line, use a straight edge and cut part way through with the knife on the face, then part off the waste from the side. Make up a block the correct depth so you can set your tile on a table, then use the block to hold the knife at the right height to slice the sides.

[Matt Whiting]

I did my basement last year with this style panel and just cut the rabbitt by hand with a utility knife. Use a new blade and a straight-edge to cut the finished side of the panel (set the blade depth so you don't cut too deep) and then just lay the panel on a flat surface, lay the knife on the same surface and you may find, as I did with my knife, that the height of the blade is almost exactly the same as the factory "ledges" on the panels. Just slide it along the edge a couple of times until you reach the depth that intersects with your first cut and you are done.

It is a little time consuming, but it makes a nice clean cut. I think a saw of any kind would likely make a mess of the edge and would throw dust everywhere so you'd want to do this outside.

Matt

[bent]

What about overcutting either the depth or the sides with the blade, will you notice any, iow, do you have to try to be perfect any more than just efficient? Did you paint them after, and did the paint match, or did you paint it all? Latex?. I don't think the fact that everything isn't square is much of an argument against doing this, but what about trying to get the layout just right. I can see this as the biggest concern/timeconsumer. Did you use a pencil, or measurements? What about keeping the amount resting over the T-track at a minimum, or centering it, keeping it even? How did that go, and what were the results. Is there a best, std., of factory gap (play) - you know extra from the inside edge to cut off. Don't know if I'll have any chance to ask anyone else who's done this. Wha, wha, waaa. Thx.

[bent]

Oh, after i read your post a second time, I realized maybe you bought this type, and just trimmed the cut sides' edges to match. 2'x2' are this type I am starting with 2' x 4' tiles that start with NO such edge, and am thinking of turning all four sides of all tiles into this type.

[Matt Whiting]

As long as you don't overcut so far as to weaken the "ledge" that you want to hold up the edge of the panel, there is no need for real precision.

I didn't paint mine as the were almost all against an outside wall and thus not noticeable. And the one edge that was visible wasn't noticeable enough to bother with paint. I think matching the paint color might be tricky and a botched paint job would look worse than the light gray panel material.

I basically measured the width with my tape and subtracted 1/8" or so. That is about how much play the factory panels had when in place so I just mimiced them.

Matt

[Matt Whiting]

OK, I didn't catch what you were doing. Yes, I bought the type of panel that drops 1/4" or so below the grid-work and only had to deal with the panels around the room perimeter that had to be cut to size. And I only had to deal with one edge most of the time, and two edges for the corner panels that were cut on two sides.

I'd had to do all edges of every panel in a room. Personally, I'd spring for new panels of drop-down variety.

Matt

[David Merrill]

I also did ceilings with 2x2' tiles which already had the drop edge and had to do the single cut edge of tiles that had to be cut for the periphery of the room. Following a tip in an old Fine Homebuilding magazine, I made a couple of cutters from 2x2x3/4-inch block of scrap wood. Cut a 3/8x3/8-inch rabbet on one edge of the block and attach a SHARP utility knife blade with round head screws to the face of the block so that it's cutting tip protrudes about 3/16-inch into the rabbet. To aid in holding the blade, I had first routed a 1/32-inch deep dado into the face of the block at a

50-degree angle to the rabbet.

I found the 2x2' acoustic tiles to be crumbly and had to regularly re-sharpen the blade to get a halfway clean cut. It was adequate since the cut edge faces the nearby wall making it inconspicuous. I wouldn't suggest trying to cut all four edges of a tile; it'll look like hell.

David Merrill

[mattyp]

Doing this with a router works amazing, about 10x faster than trying to do it by hand with a knife. The edges turn out MUCH better as well. If you have an adjustable speed router turn the rpms up as fast as it will go, have a good table, and a shopvac handy. You will not be disappointed.