Fuzzy edge on routed dado

[bigsteel15]

I just finished routing some 1/8" deep dados in birch ply (not Baltic Birch, the cheaper shop grade stuff) and notice there is a considerable "fuzzy" edge of slivers (more on the one side than the other). I don't remember it being as severe last time is did this.
The speed setting, depth and bit are the same. I am using the 23/32" dado bit from Holbren.

Is this normal?
Do I need to hone the bit possibly?

Tried going with slower speed setting but that seems to make it worse.
Feed rate doesn't seem to affect it at all.

[LCHIEN]

When i get those I just hit it with a quick pass of a sanding block.

[Tom Miller]

I wouldn't exactly call it abnormal. You can take steps to mitigate it (search for "avoid tearout", e.g.). Otherwise, do like Loring and I do -- hit it with a sanding block.

Regards,
Tom

[Wood_workur]

Make a light "scoring pass"- no less than 1/64" to no more that 1/32" deep, to score the wood fibers first. That helps a lot.


But yeah, those are normal, as mentioned above.

[JimD]

Takes less time to hit it with sandpaper than to make an extra cut. Happens in baltic birch too. Happens on solid wood. Not a big deal

Jim

[guycox]

I've been thinking about trying a technique that the scroll sawers use -- run a strip of packing tape down the seam before making the cut..

[drumpriest]

Spiral downcut bits don't have this problem. One other way to avoid it is to scrore the dado layout with a sharp knife before making your cut.

[Holbren]

I did some this weekend on the router table 3/8" deep, single pass with the 15/32" bit on 3/4" ply and some had the fuzzies. Think it was part due to my feed rate and maybe grain direction.

I know when I cut ply accross the grain with the tablesaw I always score the cut first or else I get tearout. Might be worth a try on the dado.

Either way, like Loring said, if it is too much just hit it with some sandpaper.

[Wood_workur]

Takes less time to hit it with sandpaper than to make an extra cut. Happens in baltic birch too. Happens on solid wood. Not a big deal

Jim

yeah, its all a function of how bad the tearout is. sometime, you will want to take the extra times. Most time, its not worth it, becaus4e you willn't see the fuzzies/tearout.