Widening a groove

[SawDustB]

Although I haven't posted in a while, I'm slowly making progress in the hand tool cabinet. I'm dry fitting the doors and plywood panels, and I've come to the conclusion that my grooves are just too tight. I can get the doors together, but it involves clamps and a mallet, and that's before I add glue to the mix.

The grooves for the ply are right around 7/16, and I need to make them just a bit wider (1/32 at most). The easy solution I can think of is to go back to the router table, which would work but I also worry about taking it too far. It's there any kind of easy solution I'm missing? What I want is to be able to plane or scrape the side of the groove, while keeping it square.

I know Lee Valley has a side rabbet plane for this purpose, but spending that much for all unnecessary tool seems silly. 

[riqmar]

There is another way to solve your problem: it is often helpful to cut a kerf in the center of each edge of the panel.  Said groove would be 1/2", or maybe 3/4", deep..............

[Mark J]

I agree if you need a mallet for dry fitting your grooves are too tight.  You can try coarse sandpaper on sanding block and run this on the inside of the groove.  You can also sand down the edge of the plywood that will be going into the groove. 

I've used rubber cement to glue the sand paper to the block.  This seemed to hold the sand paper well enough and then it was easy to remove the sandpaper.  

I think a plane blade is going dull on plywood really fast.  

You mentioned an "unnecessary tool",  what's that?  Is that like a unicorn?

[Tom King]

side rabbet plane.  i use an old stanley that i bought new, but would buy the LV ones if I didn't already have the Stanley.  Plywood probably will dull it faster than just wood, but they're not hard to sharpen.  I've used mine plenty of times for tuning a too tight rabbeted plywood cabinet door.

[RichardA]

Sanding the panel edge is the most sensible way to solve the problem.

[SawDustB]

Sorry, I wasn't clear on the construction. The grooves are in solid wood frame pieces, that a plywood panel goes into. If it was a solid wood panel, I'd make my adjustment there but it's maple cabinet ply with nice looking but very thin veneer. I don't think I could sand enough to make a difference without burning through.

Obviously the side rabbet plane would be nice to have.  I just figured I'd ask if there's an easier way. The specialized sanding block is an interesting thought. I could probably make one that had a large reference face that had a thinner part to go into the groove. The other thought that occurred to me was to make a reference block to hold my Japanese milled tooth file at a right angle at the correct depth. That might do the trick.

[wtnhighlander]

The saw kerf around the edge of the ply, mentioned by @riqmar above, would allow the ply panel to compress into the groove, keeping a friction fit, but with springiness that wouldn't split the rails & stiles. I'd use an inexpensive circular saw ripping blade for its narrower kerf, and disposability.  A very thin slot cutter on the router table would be easier to use, if you can find one.

Cut into the panel edge a little deeper than the groove, so the solid panel isn't driving in at the last bit.

[Coop]

Me, I’d go back to the router table and finesse it.

[SawDustB]

8 hours ago, K Cooper said:

Me, I’d go back to the router table and finesse it.

Yeah, that's the default option and I think I may fall back to it. I just find it's so easy to overshoot, so that my grooves will then all be too loose. I have to do 16 grooves to the right width, so there's an attraction to going through it quickly.

9 hours ago, wtnhighlander said:

The saw kerf around the edge of the ply, mentioned by @riqmar above, would allow the ply panel to compress into the groove, keeping a friction fit, but with springiness that wouldn't split the rails & stiles. I'd use an inexpensive circular saw ripping blade for its narrower kerf, and disposability.  A very thin slot cutter on the router table would be easier to use, if you can find one.

Cut into the panel edge a little deeper than the groove, so the solid panel isn't driving in at the last bit.

Using a slot cutter for it seems like the way to go for this technique. I couldn't picture how to safely run the panels over the table saw to do it. The panels are supposed to be glued in for tools to hang on. Do you think this would compromise the strength of that bond at all?

[Mick S]

I'd set up the router table for the same exact cut I had it before, test it and when it's dialed in perfectly then run painter's tape the length of the fence top and bottom (if the panels were originally cut vertically) or just along the bearing surface if they were cut with a horizontal slot cutter. The thickness of the painter's tape should open the groove for a good fit.

[Tpt life]

There is a chance no painters tape will be needed. Sometimes the exact “same” pass a second time will create the breathing room you need. That said, I like Mick’s path for efficient and Tom’s for picky. 

[wtnhighlander]

1 hour ago, SawDustB said:

 The panels are supposed to be glued in for tools to hang on. Do you think this would compromise the strength of that bond at all?

If they are glued in, I would favor enlarging the groove to fit. But I doubt the kerf method would affect the joint adversly, anyway.

[Dave H]

I had a similar problem with some cabinets for my kitchen I glued a sanding belt for my belt sander to some ply wood scrap with a straight edge then I brad nailed a scrap wood fence to the sanding block to the depth of the groove and used this to sand the ply until it fit into the groove without beating the sh_t out of it. Good luck

[SawDustB]

In the end I went with Coop's suggestion and used the router table. I lined up the fence with the previous groove, then used paper to space it over 10 thou. That made all the difference to the fit. It only took me about 20 minutes to set up and run them all through. I also added a tiny chamfer on the edge of the panel going in the groove, so they'd slide in easier.

[Elizabeth.B]

Hey SawDustB,

You have use routertable. Please guide me in buying one all-in-one routertable for my workshop.

[Mark J]

Welcome to the forum Elizabeth.B.  

I assume by all in one you mean a table + lift + router?  If I were looking today I would start with the SawStop table and lift and compare others to it.  For a router I suggest the big Porter Cable.  

[SawDustB]

I think for a router table it really depends on your budget, your space, and what you want to do with it. @Mark J has suggested an excellent setup if you want to go with a higher end (and is probably what I would do if space and budget weren't a concern). For me personally, I have the fixed base from my Porter Cable 1 3/4 HP variable speed router attached to a Kreg plate in the wing of my table saw. It gets the job done, and having it on the table saw saves space and helps with stability (as compared to a small bench top router table). Even a cheap and simple router table, which can be as crude as a piece of plywood with your router bolted to it on a couple of sawhorses and a piece of wood for a fence, is extremely useful.

You can see mine here in my table saw wing with a flush trim bit in it:

[Immortan D]

Glad you solved the problem.

As a side note, I have the LN pair of side rabbet planes and I've found them very difficult to use on grooves. On dadoes I was unable to make a cut with them at all. I'm sure it's me and not the tool, I just couldn't get the hang of those planes.

[Tom King]

If the irons are sharp enough, and not projected out too far, it should be really easy to use.  Were they just not cutting, or grabbing and too hard to push.  There is no faster, and easier way to do it if the plane is properly set up.

18 minutes ago, Immortan D said:

Glad you solved the problem.

As a side note, I have the LN pair of side rabbet planes and I've found them very difficult to use on grooves. On dadoes I was unable to make a cut with them at all. I'm sure it's me and not the tool, I just couldn't get the hang of those planes.

 

[DerekMPBS]

10 hours ago, Elizabeth.B said:

Hey SawDustB,

You have use routertable. Please guide me in buying one all-in-one routertable for my workshop.

Hi Elizabeth,

Welcome to the forums.  I have the Kreg router table, with casters for mobility.  I haven't added a lift yet.  If I had known when I was looking at router tables that I would be buying a Sawstop cabinet saw, I would have foregone the table and bought the router wing for the Sawstop.  I may do that anyway at some point - one can never have too many routers, or tables.....or something like that.

[Elizabeth.B]

Thanks Mark J and SawDustB.

I would like to tell you that dont worry about price. I just want to buy a high featured routertable.

[Immortan D]

20 hours ago, Tom King said:

If the irons are sharp enough, and not projected out too far, it should be really easy to use.  Were they just not cutting, or grabbing and too hard to push.  There is no faster, and easier way to do it if the plane is properly set up.

 

The planes cut fine when I use them on an edge, just to try the setup, but when I try to cut dado walls I find it very difficult. Maybe I should set the fence a bit lower, so as to prevent the base of the plane from touching the bottom of the dado if you know what I mean. I will try that next time.