Flush trimming hardwood edging

[FS7]

Previously on FS7's shop: I'm in the middle of building a desk for my wife, who abuses her things. I decided to make the bulk of the top replaceable plywood. There are three panels in an L shape, with the hardwood edging being 3" thick in a pseudo-rail-and-stile configuration. I used lap joints on both sides to create an inset (with a 3/4" rabbet all around) for the plywood to screw into. I did my best to make the actual dado depth 23/32",  but there are always imperfections.

It looks pretty good at this point, but I'd like to flush the hardwood with the plywood surface. This is a careful operation, since the veneer (like any other) is about 1/40" thick. The hardwood is the proud surface, which is good, but I'm wondering what my options are. Flush trimming with a router bit isn't going to work, though it might work really well. I can't move the giant piece on the table. I tried masking the plywood with painter's tape and sanding the hardwood with 60 grit, which worked, but was slow going. Also, the heat mangled the tape and it didn't come off clean, plus I had to deal with the thickness of the tape. What's worked the best so far is the plane - I don't have many hand planes, just a small block plane and a regular bench plane, but despite being entry-level tools they work well enough. 

I imagine most people would be OK with the wood being off by about 1/64" or so, but not me. Is there a better way that I'm missing? Different type of hand plane? Some sort of shop-made contraption? I saw a "flush trimming" plane made with an old iron, but I'm not sure that would work here. 

Presently my thought is to clamp a guide along the plywood that's about the distance from the edge of the bench plane sole to the iron and just be more aggressive with the hand plane. This would theoretically spare the plywood. Not sure that's worth the effort though and if I'm off, one good pass and there goes the veneer.

I am aware that I started with the fact that my wife abuses things and I'm definitely overthinking and overengineering something that will be abused, more or less, but I like to try anyway. If nothing else it will make for good pictures for my business.

[cputnam]

Do you have a flush trim base for your trim router? That is one option. I would use a shoulder plane and a fence to get that last /64" reduced.

[Bill_de]

Previously on FS7's shop: I'm in the middle of building a desk for my wife, who abuses her things. I decided to make the bulk of the top replaceable plywood. There are three panels in an L shape, with the hardwood edging being 3" thick in a pseudo-rail-and-stile configuration. I used lap joints on both sides to create an inset (with a 3/4" rabbet all around) for the plywood to screw into. I did my best to make the actual dado depth 23/32",  but there are always imperfections.

It looks pretty good at this point, but I'd like to flush the hardwood with the plywood surface. This is a careful operation, since the veneer (like any other) is about 1/40" thick. The hardwood is the proud surface, which is good, but I'm wondering what my options are. Flush trimming with a router bit isn't going to work, though it might work really well. I can't move the giant piece on the table. I tried masking the plywood with painter's tape and sanding the hardwood with 60 grit, which worked, but was slow going. Also, the heat mangled the tape and it didn't come off clean, plus I had to deal with the thickness of the tape. What's worked the best so far is the plane - I don't have many hand planes, just a small block plane and a regular bench plane, but despite being entry-level tools they work well enough. 

I imagine most people would be OK with the wood being off by about 1/64" or so, but not me. Is there a better way that I'm missing? Different type of hand plane? Some sort of shop-made contraption? I saw a "flush trimming" plane made with an old iron, but I'm not sure that would work here. 

Presently my thought is to clamp a guide along the plywood that's about the distance from the edge of the bench plane sole to the iron and just be more aggressive with the hand plane. This would theoretically spare the plywood. Not sure that's worth the effort though and if I'm off, one good pass and there goes the veneer.

I am aware that I started with the fact that my wife abuses things and I'm definitely overthinking and overengineering something that will be abused, more or less, but I like to try anyway. If nothing else it will make for good pictures for my business.

I like the V groove

https://www.amazon.com/Freud-Flush-Groov...uage=en_US

--

[JohnnyEgo]

Hand plane seems fine. Won't take long to knock a 64th off the edge. When you get close, just position it so the edge of the plane body just to the side of the mouth is over the plywood. Then you will have nothing to worry about cutting the plywood veneer. This is the way I usually flush up edge trim on ply. If you really want to be sure you keep the blade off the ply, then sure, a fence is a fine solution, but I have gone this route plenty of times with nothing more than a little patience and attention to the task.

If you do want to go the trim router path, there is a gadget I love for flush trimming, although it is not without it's dangers and detractors. It is called the 'Little Lipper', it's made by Fast Cap, and it runs about $40. It gives you a much larger bearing surface that is much easier to keep the router at a 90° angle on edge than relying on your good balance and the bit bearing to do it. The danger is that you are putting a hand close to the spinning bit, and it does not reward inattention. But as long as you are paying good attention, I have found it to be very effective in edge trimming without getting a bunch of dips and gouges.

[iclark]

You said that the plywood top is replaceable.

That means that the next plywood top may be thinner or thicker than this one.

Do not flush the hardwood.

Shim the plywood so that it is flush with the hardwood edging.

A strip or 2 of veneer under the plywood in the rabbit ought to do it.

[FS7]

You said that the plywood top is replaceable.

That means that the next plywood top may be thinner or thicker than this one.

Do not flush the hardwood.

Shim the plywood so that it is flush with the hardwood edging.

A strip or 2 of veneer under the plywood in the rabbit ought to do it.

That is not a bad idea and I had considered the possibility of potentially thicker plywood in the future. I did make this with 1/2 MDF and 1/4 nominal plywood, so they should be fairly consistent in thickness.

I think the V-groove is a good solution, though a bit like that wouldn't work in this case. A very light pass with a clamped fence would let me try this.

[jteneyck]

You said that the plywood top is replaceable.

That means that the next plywood top may be thinner or thicker than this one.

Do not flush the hardwood.

Shim the plywood so that it is flush with the hardwood edging.

A strip or 2 of veneer under the plywood in the rabbit ought to do it.

This.  ^^^

John

[Willyou]

What you are trying to do is very difficult due to the thin veneer. Also, that thin veneer won't last long with abusive use. Have you considered using plastic laminate instead of or on top of the thin veneer you have now? It will take a lot of abuse and it comes in many nice wood grain patterns. Also, edge treatment is a whole lot easier to deal with. If the laminate does become so damaged or worn that it needs replacing, it is easy to layer another sheet over the old one without the need to replace the whole plywood top. I did this many years ago in my wife's sewing room. It still looks good.
Another alternative would be to cover the thin veneer with a thicker one that you can deal with.
I also like the idea above of getting the hardwood edge as close to even as possible and then create a shallow v-groove along the joint line.

[Cooler]

There are two approaches, the first using a flush trim bit.



The second using a dado bit:


I do like the second method even if it does require precise depth of cut adjustment.  Full plans here:

https://www.canadianwoodworking.com/plan...router-jig

[FS7]

Typical flush trimming won't work because the edging is three inches wide. Planing and sanding worked well enough, though I did sand through the veneer in one spot (I had forgotten that the screw caused some bulging from underneath, and when that was smoothed that area was crowned and the veneer much thinner). No margin for error there, so I put in an accent strip. Looks like a random design feature now.