Edge Rounding and Corner Protectors

[Blackadder]

The ½” plywood does not seem to give a lot of room for edge rounding – the screw heads are close to the edge. I’ve tried rounding with a ¼” round over router bit, but the corner protectors commercially available leave a gap and seem to need a bigger radius round over.

What radius round over doe others use – and what do you do – just sink the screws in further? Does this not leave the wood at the corner too thin?

Thanks

[Tim A]

Plastic are 3/8"r, most metal are 1/2"r, some are 5/8"r.

Remove the screws and fill the holes. Once the PL is set the screws are useless.

[SoundInMotionDJ]

I use a 1/2" round over bit for corners, and 1/4" for freestanding edges like the mouth of a Titan.

If there are screws you should pull them before doing the round over. I'd wait to fill until after you round and sand...the remaining holes are pretty small.

I assemble cabinets with 15ga finish nails. The router goes through the nails like they are not even there. For the most part I do not even have nail holes left to fill on the edges.

As a bonus, the 1/2" round over will help to "flush trim" any slight overhangs on the panels. On future Titans, I plan to cut the sides about 1/8" oversize all round and trim it flush with the round over bit. That is *much* easier that stressing over the alignment...especially when adding the second side.

--Stan Graves

[LelandCrooks]

As a bonus, the 1/2" round over will help to "flush trim" any slight overhangs on the panels. On future Titans, I plan to cut the sides about 1/8" oversize all round and trim it flush with the round over bit. That is *much* easier that stressing over the alignment...especially when adding the second side.

--Stan Graves

I use this, and over size all exterior panels a tad. Then roundover.

[SoundInMotionDJ]

Same idea. I have one of those, but decided to just use the roundover bit...one less pass and one less bit change.

--Stan Graves

[Nordskov]

Then roundover.

Hey LeLand.

Does that 'thing' come with batteries?

[Frankenspeakers]

To quote a female acquaintance... "If it don't take D cells it's useless!"

[LelandCrooks]

[AntonZ]

Not familiar with that "roundover" position, but the device looks interesting.


I'd like to fit plastic corners to my all 9mm (3/8") T18. The roundover treatment with a 1/4" bit is not round enough for the corners. Still in doubt about another pass with the 1/2" bit. That might take a little too much off the edges. On the other hand, a scrap piece looked OK.

Anyone ever tried 1/2" roundover on 3/8" ply?

[DAVID_L_PERRY]

I use this, and over size all exterior panels a tad. Then roundover.

+1
I do exactly the same. I only overshoot the panels by the smallest fraction(just enough to feel it under the finger), but enough that it is worth while using the straight edge bit.

I used a 1/2" roundover bit on my titan 48 1/2" panels with no problems and this allowed the ugly (but necessary ) plastic corners



I recess the screw heads as far as I can.


I have found it best to use a countersink bit no bigger than the dia of the screw head.



I had a couple of screws that just got touched by the router (couple of sparks), other than that it was simple.

Dave

[LelandCrooks]

I think I have found some corner protectors that are tailor made to the 1/2 ply in Penn Elcom. METAL! I'm going to order some samples and try them out. It will be after the first of the year.

[fender3x]

I think I have found some corner protectors that are tailor made to the 1/2 ply in Penn Elcom. METAL! I'm going to order some samples and try them out. It will be after the first of the year.

I have rounded the edges of three cabs with 1/2" roundover, and I think I use the corners that Leland is ordering. I like the way they look, and they fit nicely.

I used 1/2" roundover on the back of a DR where 1/4" plywood attached to the 1/2" top and sides. No problem rounding it over with the 1/2" roundover bit. I tested first on some scrap that I glued together first. It does not take off enough wood to really effect the bond even on 1/4"

This may be the only time I disagree with Dave Perry, tho... mainly because I am cheap. I ALWAYS pull the screws, fill the holes and then rout. It takes a bit more time, but I think routing a screw by accident can cause more than sparks. I don't know about safety (I am still a tad afraid of my router), but I know for sure what a nice Freud bit costs!

[Tim A]

Again, while a 1/2" will work, all you need for a perfect fit is 3/8". Why take off more than necessary?

[AntonZ]

When the weather has become good enough again to make sawdust outside, I will try some different rounding bits on scrap corners of 9mm ply and take pics for reference.