Thin plywood dado help

[Robert Hayward]

What should I use to cut a dado that fits the thin plywood pictured? Normal 1/8" blade kerf produces a way too sloppy fit. I am making pencil boxes and using the thin plywood for the bottoms.

[Richard Coers]

Metric router bit

[Brian Tymchak]

You could use a thin kerf blade in the TS. My freud thin kerfs It will cut about .090 grooves. Make 1 pass then bump the fence out a touch to fit. Use test cuts to dial it in.

[Lee Schierer]

I recently purchased a sheet of 1/8" plywood from Woodcraft and made an egg crate for a chess set and for a tea caddy. The plywood measures exactly 1/8" thick on my Harbor Freight digital calipers. My Freud cross cut blade cut a groove that cut the slots in the plywood for the egg crate and they fit perfectly. No slop in the joints.
498759
If the bottom is contained on four sides, a tiny bit of play is no problem, it can't get out. You could also glue it in place.
Or.....
You could use a thin kerf blade that cuts 3/32 kerf and make two passes if needed.

[Kent A Bathurst]

I recently purchased a sheet of 1/8" plywood from Woodcraft.....measures exactly 1/8" thick.......

We have a winner. Stroll over to the Tampa Woodcraft and get some 1/8" Baltic Birch plywood. Can't need much for pencil boxes.

OR - take a narrow [1/2"] strip of your plywood, glue it along one side/edge of the target plywood to double the thickness, and make the groove to fit.

Get wood to fit the available tooling.

[Patrick Varley]

You could also get 1/4" plywood and rabbet the edges to fit the 1/8" dado.

[Rich Engelhardt]

Sounds like a perfect place to use a thin kerf blade along with a kerf maker.
https://www.youtube.com/watch?v=SOTqqSEtvng

[Robert Hayward]

Metric router bits also have metric shanks from my experience. I have 1/4" and 1/2" collets only. Do not own a thin kerf blade. These are the reasons I posted here.

I had no idea the Woodcraft 1/8" ply actually measured 1/8". With the exception of the aircraft grade ply I use for my RC airplanes which is priced like the plys are gold leaf I thought all 1/8" ply was undersized these days. 22 miles each way to Woodcraft in battlefield conditions traffic is worth the drive tomorrow I think. Cheaper than a new thin kerf blade or a metric bit and collet.

Lee, nice egg crate box. What style hinges are on that box? I am going to try a hinged lid on at least one pencil box with 3/8" thick wood sides. The thin ply bottom is contained on all four sides by the way. Still I do not like the loose 1/8" / 3mm fit.

Thank you everyone for the suggestions.

[Earl McLain]

I have a few circular saw blades i use to make Celtic Knots in turning blanks. One is a 7.25" with i think like a .08" or or so kerf, another 6.5" that is right at 1/16", both offer a fine cut. Lose some cutting depth compared to a 10" blade, but not of consequence in a 9/16" deep kerf cut. Long as you have a 5/8" arbor, don't overlook smaller diameter blades. (SawStop users will likely have to use their bypass, or switch to a very fragile router bit.)

[Kris Cook]

3mm blade for your router plane is $19.50 at LV.

[Steve Eure]

Check the kerf size of a 7 1/2" circ. saw blade. You can use it in you TS if the bore size is the same.

[Robert Hayward]

Do not know why I never gave a thought to a 7 1/4" circular saw blade. I spent a lot of years of my life in construction and probably have 20 7 1/4" blades stored hear and there. In new condition to useless and I have no idea why they are hanging on the pegboard. One of them surely has a thinner than 1/8" kerf.

[Rod Sheridan]

What should I use to cut a dado that fits the thin plywood pictured? Normal 1/8" blade kerf produces a way too sloppy fit. I am making pencil boxes and using the thin plywood for the bottoms.

I use a 1/16” slotting blade in my shaper for narrow slots, it’s a saw blade so you could get in any bore you want, mine is 30mm, use it in your saw.

Regards, Rod

[Ron Selzer]

Without going to the shop to check, I bet a steel blade would work for you. The old fashioned blade we had before carbide tipped came along

[Vince Shriver]

I've been thinking of using 1/8" B/B plywood for miter joint splines. Anyone do that?

[Robert Hayward]

I've been thinking of using 1/8" B/B plywood for miter joint splines. Anyone do that?

If you decide to try it see if you can get 1/8" aircraft grade birch ply in 5 or 6 ply. Not even close to being cheap but the edge grain looks a whole lot prettier than 3 ply BB 1/8".

[Jim Becker]

As long as the arbor hole matches your saw, you can use a variety of smaller diameter blades designed for hand-held saws to get creative with kerf width when grooving.

[Patrick Varley]

I've been thinking of using 1/8" B/B plywood for miter joint splines. Anyone do that?

I've not used plywood, but I have laminated veneer to make splines. Essentially DIY plywood. Nice because you can use contrasting woods to get creative. You can also do something as simple as veneering a piece of solid wood with contrasting veneer to get a striped appearance. All essentially a derivative of making inlay banding.