Small radius round over - full size router or laminate trimmer?

[Greg Guarino]

Next in my continuing series of kindergarten woodworking questions:

5/32 roundover bit, oak. 72" x 30" rectangle to be rounded over. Which would you use? I'm leaning towards the smaller one. Am I wrong?

[dpb]

There's no "right or wrong" there; the trimmer would certainly handle it fine and be a little easier to handle. How much of a decision it would be would mostly depend on just how large "full size" is...that's a sizable possible variation from something not much larger than a trimmer to a 3+ hp behemoth.

IOW, suit yourself. (And, if you end up taxing the trimmer sometime you'll certainly be able to tell it and can change then.)

--

[SonomaProducts.com]

I think lam trimmers are typically hard to control for shaping ops. If you make or have a bigger base they are better. If you only have a 3hp monster then a trimmer might be a better choice. If you have a 1 3/4 hp fixed base it would be my preference.

Of course I don't follow my own advice and I have my 1 3/4 in my router table and my 2 3/4 hp as my free hand but I am looking for a trimmer and will likely get a second 1 3/4 for free handing.

[Greg Guarino]

Well, a small sample size so far, but exactly what I expected: A tossup. A matter of what feels best to the individual user. I will, as usual, abuse some of my scrap pile before working on the actual project.

So let me ask a related question. This is a 1x2 border around the edges of a desktop. Although my inexpertise may trip me up, rounding the horizontal edges seems straightforward enough. What about the vertical corners? I'd like to round those as well, But I can foresee difficulties.

Could I clamp a block both above and below to "extend" the corner, allowing the router base more "land" to sit on at the beginning and end of the cut? If so, I suppose I'd have to make these cuts first, before tackling the horizontal edges. I suppose I should also turn the desktop on its side, to allow the router to be used vertically.

Or should I just do it with a sanding block, by eye?

[SonomaProducts.com]

I suppose you could do it with a router but vertical rounding is always a difficult situation.

You sould consider that you may blow out the grain as you exit or even enter the cut and that wouldn't be nice on the tabel top. Also be careful of blow out on the ends when you do the horiz too. Maybe a backer block or do climb cuts at the exit corners.

I would sand the verts. If you want it very precise then do the vertical corners first and before you do it, draw the radius on the top of the table. This is how round overs and chamfers are done when using a hand plane in either axis. You would be surprised how nice/ precise of a large round over or chamfer you can get with a hand plane if you draw the shape first. You can do the same with a sanding block. Use a very stiff block, not rubber or felt, rather a piece of wood so you have good control. Actually 5/32 is almost 3/8's right, maybe a block plane would be a good start, that is a lot of material but could be sanded.

[SonomaProducts.com]

My first reply isn't showing up for some reason. Forgive if a repeat.

Be careful of blowing out the grain when doing horiz but especially when doing vert with router/traimmer. Use a backer block or climb cut the exits.

To do by sanding or block plane, draw the radius on the edge first, it nakes it very easy to have a precise round over or chamfer with a plane or sanding. Use a firm sanding block like wood, not felt or rubber.

[Greg Guarino]

Thanks for the advice, but I'm not clear on some of the terms. I think I can guess what a backer block would be, essentially an extension of the table top so I don't screw up the edge. But that would change the profile at the corner (I'm better at geometry than woodworking). Would you just hand sand the last little bit?

What is a "climb cut"?

You had me worried there for a second, but 5/32 is 1/32 more than 1/8, so a fairly small radius. I am thinking of hand sanding the corners. I'd rather live with a tiny bit of imprecision than an ugly gouge.

Speaking of sanding, can I assume that I'll need to hand sand the rounded edges, without a block, even? And while we're at it, would you do any coarse sanding before making the roundovers?

[SonomaProducts.com]

Yes you have backer idea correct. Routers love to blow out the grain when you hit the end grain.

Climb cutting is the tern for routing in the opposite direction. You normally cut by pusing the cutter into the material but climb cutting is moving in the same direction as the cutter so in essence the bit wants to start climbing along the wood. ZIt just means go backwards fir a while. So you rout up to about 1 inch from the end, then start your cut from outsied and come back in the wron direction to get that last inch. You can climb cut around the corner or sand it as you said.

No need to sand the sharp edge before routing. The actual proper method of rounding over is to round over slightly too much, cutting like 128th of an inch too deep and then sand off the ridge. Most people try to just barely undercut so you don't get a ridge. I actully do the later because the flatness will likely vary and you will likley tilt the router a bit and have a few sections with ridges anyway.

[dadiOH]

Here is a definitive answer: it depends.

You said elsewhere that you are putting a 1x2 - actually 3/4 x 1 1/2? - onto a piece 72" x 30"; banding a piece of ply IOW. Which way are you putting the band, vertically or horizontally? If vertically, you could use either but the easiest would be the big router riding on the top surface. If horizontally, use the big router riding on the top surface; trying to keep

*any* router vertical riding on a 3/4" surface is difficult.

If course, there are alternatives to a router...

1. Radi-Plane 2. Any small plane 3. Shoemaker's rasp. These are so handy that it is beyond my ken why anyone messing with wood doesn't have one. the corners (mitered?), forget a router. Use a rasp, sandpaper, whatever. ____________________

BTW, have you considered how you are going to get the banding flush with the ply? It isn't going to be, even if you use splines or biscuits. Of course, there is "flush" and *FLUSH*! To me, it isn't flush if I can feel it. Getting it flush will be more of a problem if - as I suspect - you plan to put the banding on horizontally simply because there is more to remove to reach the Valhalla of Flushdom.

The problem really isn't getting the banding flush, it is getting it that way without screwing up the plywood. Time was that ply face veneers were

1/20, even 1/16. No more; I find it miraculous that they can cut them as thin as they do.

Here are some conventional ways of flushing...

1. Horizontal router table with trimming bit and bearing. Good because bit is cutting with the grain resulting in a smoother cut. Bad because the workpiece has to be elevated above the table by at least as much as the amount to trim.
2. Hand held router with trimming bit and bearing horizontal to ply. Good for same reason as above, bad because the router has to ride on a narrow edge. Fix the bad part by clamping a 2x4 to the banding so you have a wider surface for the router.
3. You can also use a router either in table or by hand with the router perpendicular to the ply. That means the bit is rotating crosswise on what is being cut and the cut will be less than smooth. It also means that either the ply - in the case of a table - or the router if using by hand has to be elevated by at least as much as the amount to trim.
4. I have also used planer blades in a molding head on a radial saw to do it. Inboard edge of planer blades were just shy of the banding/ply line and the saw head was tipped slightly.
5. Sanding. Forget it.
6. Plane. Blade has to be very sharp, has to be set to take very thin shavings and you still have to be very, very careful. The banding corners will be a PITA unless you band two parallel sides and flush them before appling the other two pieces of banding.
7. Scraper if there isn't much to take off.

There are two ways to make using a plane easier...

1. Taper your band slightly outward before applying it. That means you will have to take off much less to get ply and edge of band flush.
2. Put on a piece of thin - 1/8 - 1/4 - banding, make it flush, then apply your wider band, preferably tapered. That thin band of solid wood gives you a bit more wiggle room for errors without messing up the plywood.

[Leon]

Piloted bit, I would go with which ever you prefer. Using a non piloted with a edge guide definitely the larger of the two.

[Larry Jaques]

you're ready for.

Microplanes are no slouch here, either.

3. Shoemaker's rasp. These are so handy that it is beyond my ken why

The problem with most rasps on the market is that most are at least 4x too coarse and/or 4x too expensive. I got by with a 4-in-hand for decades before finding an import #49 for 1/3 the price. They're wonderful for opening up holes to ease an oversize 120v plug thru.

To Greg, I haven't yet seen anyone mention a ROS, but fine paper on a sander is a great way to ease corners if you have a lot of them to do at once. A hand sanding block is good for just a few, as you said.

-- The ultimate result of shielding men from folly is to fill the world with fools. -- Herbert Spencer

[Greg Guarino]

OK. So here's where you get to scold me a bit. I walked around HD and decided that the most cost- and time-effective strategy (both important factors right now) for this desktop would be to start with a solid-core door. I recently finally put a finish on one I had installed in a hurry some years ago and saw how it looked on the sawhorses. An idea was born. More on the pitfalls I discovered further down.

Which way are you putting

I was thinking about that too. The door is a little thinner than the

1.5" "one-by-two". I definitely planned on rounding the top edge from the top, but I'm thinking about how to do the bottom edge. Having the router balance on the 1" edge (I put a contrasting band of thinner wood in-between) didn't sound like a good idea. I thought I might stand the desktop on its side an run the small router along the 1.5" side. Another option would be to just knock the (bottom) edge off with sandpaper, but I'm not sure that would look as nice.

again recently was determined to fool with it until it became useful. I got it a little better, but didn't really succeed.

> 3. Shoemaker's rasp. These are so handy that it is beyond my ken why

doubt my ability to do an even job over a six-foot length with either of those methods.

Not mitered. I decided I liked the look better the other way. Oh hell, here's a photo:

another:

'm sure I will get comments that the long clamps are too far apart on the short edge of the desk top. If I remember correctly, I was able to use the "bow" of the 1x2 to my advantage on that end. The other end needed some creative problem solving]

I said I'd get back to the pitfalls of using a door. The door I bought, UN-like the ones I bought some years ago, has very thin veneer indeed. That came as an unwelcome surprise. Suffice it to say that one of the spots for a large "cable grommet" has been chosen for me. Luckily it is near the rear edge of the desk, about where I might have put it anyway.

This is my first real project in quite a while, and one of the lessons learned has been to look into better materials for the next one.

I tried this (sans extension) with the lam trimmer on a test piece, but with only the inner banding in place. It worked very nicely over most of the piece, but dug in in one spot. That worries me, and I probably won't try it on the desk.

Tried that on the inner banding. See my comment above re: the cable grommet. It's a learning experience. :)

I have two ideas about this. The first is to live with the imperfection. It is pretty flush much of the way around, but you can feel the edge and even see it here and there.

The second is to use a (Stanley #78)rabbet plane. I'm missing one part, but I've found it online. I figure that I could set the "rabbet width" to the width of the banding and set the depth stop to stop the cut at the height of the door veneer. Thin as that is, though, I'm even worried about having the depth stop ride over it. (I've already done some sanding).

I may go with #1. We'll see. :)

[dadiOH]

It's still ply even if the interior is particle board or MDF. Most likely particle board with 1/8 fiber board on each side with thin wood (luan?) veneer on top of each of those. _________________

Logical, thick door. _______________

Too late now but you could have rounded it before you put it on. _________________

That's the only way you *can* rout it now. ______________

Your problem was...? ______________

>>> 3. Shoemaker's rasp. These are so handy that it is beyond my

> I doubt my ability to do an even job over a six-foot length with

No one is going to be checking the uniformity with a micrometer.

Either is easy to use and much faster than sandpaper. I once did about 40' of handrails for my sailboat...it was bandsawed as much as possible but all the rounding - LOTS of rounding - was done with a 4 in hand rasp. Didn't take all that long, 3-4 hours maybe. ________________

Those are dowels? If you had clamped, drilled at a slight angle and then insertted the dowels you wouldn't need any clamps other than 1-2 while drilling. Ditto with screws and face grain plugs. ________________

Good luck on finding them. _________________

I assume you were running the router with the base on the 1 1/2 side, right? With a trimming bit with a bearing, right? If it dug in then you had to have tipped it toward the outside. Set the cutting depth so that the cutters are at or just shy of the ply, guide the router with one hand and use the other to firmly hold the base against whatever it is riding on.

Why in the world would you bother trying to use a rabbet plane? Really unneeded complication.

If you do, no woodworking merit badge for you :)

[Greg Guarino]

Judging by the end I cut off and what I saw when I sanded too deeply in one small area, that sounds about right. Having just sanded and finished an older (also HD) door, I wasn't expecting that.

I don't have a router table, but I suppose I could have rigged something up, maybe with a second piece of 1x2 adjacent to the work piece to provide more "land" for the router to ride on. Maybe next time.

This desk is going to back up to a wall. Maybe I'll try the back edge first and then decide.

We've established that my woodworking skills are modest, but it just didn't seem possible to make a smooth cut. The cutters are made of thin material. I think this is part of the problem. They don't seem rigid enough and must flex a little during the cut. I surmised that the front cutter would need to be shallower than the rear, but could never come up with a combination that worked well. If your goal was a very very slight roundover , maybe.

>>>>> 3. Shoemaker's rasp. These are so handy that it is beyond my

>>> I doubt my ability to do an even job over a six-foot length with

Yes. The "tight" ones I mentioned elsewhere.

If you had clamped, drilled at a slight angle and then

That's very much like what I did, actually. But I used five clamps along the long sides. The 1x2s, while the best ones I could pick out of maybe

20 that I fished out of the HD rack, were not 100% true. They needed a little persuasion to straighten them out while I drilled the holes. I didn't deliberately drill them at a slight angle, but a slight angle was what I got. :)

It seemed that while the Forstner bit made a nice clean hole, it may have had a greater tendency to wander.

After I drilled the holes I took off the clamps, applied glue and put the strips back on with the dowels and clamps. Am I reading you right - with dowels I wouldn't have needed clamps for the glue-up? Really? As tight as the dowels were, and with the "slight angle", I suppose it might have held straight pieces OK. But one of my end pieces was bowed enough that I could see light through the middle section.

That was my puzzle for the day. I only had two clamps that long, and I had dowels sticking out from the holes. I cut down the dowels, but there was still maybe a sixteenth left, enough I thought to prevent me from using a piece of wood to spread out the pressure. I found three pieces of 1/8" ply and put them in the areas between the dowels, then clamped a long piece of scrap to span the whole length. (you can see this in one of the photos) That almost worked, but there was still a small gap in the middle. I took out the middle piece of 1/8" ply, put maybe 8 layers of painter's tape on it, stuck it back in and tightened the clamps again. That extra thickness did the trick.

As ass-backward as that undoubtedly was, It Ain't Comin' Off. I think it might even rate a merit badge. Perhaps the coveted "It Was All Wrong But It Worked" badge.

People have given me some good prospects nearby.

Yes

If it dug in then you had to

It seemed to "grab" all of a sudden, like "smooth, smooth, smooth, bind, DIG".

Too late for that. All four sides are on.

That's what I've got, actually. A 1/4" band and a 3/4" band.

Maybe so, but there'd be no chance of running over onto the veneer, and there'd be a set depth too. Better yet, I'd get to say I used that odd contraption for something.

In all seriousness, I'm having a good time doing this, even though I've already made a couple of significant mistakes. I figure the next project will be even better. That's enough for me. Thanks for the tips. I'm sure I'll be needing more.

[Greg Guarino]

I gave this a try last night and I have to say it worked very well. I set the fence on the rabbet plane by eye with it sitting on the edge of the work. Freed from having to worry about running over onto the veneer somewhere along the 6' length, I was able to trim down the oak nicely. Here and there I used a block plane in the corners.

Perfect? No. But pretty decent. It was pretty close before I planed it; at least half of the perimeter I left alone. I could have lived with the rest, but the "merit badge" comment shamed me into it. :)

[dadiOH]

I'm glad it worked for you. I still think it overkill but you are entitled to the merit badge :)