How would you deal with this misplaced mortise on a workbench leg?

[Karl Leboeuf]

I am trying to build the 'Woodwhisperer Hybrid Workbench' and referenced off the wrong face while routing one mortise on one of the legs, offsetting my mortise by about 1/4" toward the 'back' of the leg. I am trying to decide how to proceed and was hoping for some guidance.


The mortises are 1" wide x 3" long x 1 3/4" deep. I am excavating them with a router, 1/2" spiral bit, and edge guide. Immediately after removing the first 1/2" of a mortise for the front rail, I noticed that I referenced off the wrong side of the leg, offsetting the mortise about 1/4" towards the 'back' of the workbench.


Below is a picture of a 'back' leg with the mortise in the right position. I still need to excavate the remaining 1/2"-wide cross-hatched area to get 1"-wide mortises. The leg is 4" x 3 1/2". All parts are made of ash.
good mortise small.jpg


And here is the 'front' leg with an offset mortise for the workbench's front rail.
bad mortise small.jpg


I was writing to get some opinions on the preferred fix. I had a few ideas but I do not have the experience to know whether any of them are obviously bad or obviously correct.

1. I could offset the tenon on one end of the rail to match the offset mortise. In other words, one of the tenon's shoulders would be quite wide, and the other would be teeny (about 1/16", see picture below -- my rail stock will just barely cover the mortise). This approach wouldn't have any cosmetic impacts (same reveal for all tenons, my shame is completely hidden, etc.) Is this a bad idea for structural reasons -- does it matter if one of my rail's tenons has asymmetric shoulders?
   tenon stock small.jpg
   In case this information is relevant to the problem -- this bench design is about 35" tall, the front rail is about 5" from the floor, it's 4" tall, 45" long, and 1 3/4" thick. There is no 'top' rail, but the benchtop is going to be about 3 1/2" thick. The benchtop will be secured to the base using 4 big SPAX screws.
2. I could repair / fill the mortise and rout one where it's supposed to be. My main concern with this approach, aside from it being a bit of a hassle, is that one of the walls for the correctly located mortise will be made from the repair material. I feel like this makes it very important to get the filler piece 'just right'. I could use epoxy instead of wood glue for better gap filling.
3. I haven't excavated the 'mating' mortise on the other front leg yet. I could repeat what I did and just have an extra ~1/4" reveal on the front rail. I would lose 1/4" of potential shelf space but I am prepared to live with that. This design only has a single rail in the front and back of the bench, which could minimize how 'wrong' it looks. The side rails have a 3/8" reveal.
4. I could make a new leg. I want to avoid this because it would take quite a bit of time for me. I'd be willing to accept a slightly uglier bench (it's just a bench!) before making a new leg.
5. If anyone has any better ideas I'd love to hear them

My preference is #1 unless someone identifies that it's a bad idea. #3 would be easiest but I don't have a sense of how ugly it'll look or if it's even noticeable. I appreciate any feedback and help!

[Cameron Wood]

I would glue in a tenon from the same wood and recut- no big deal. The rest of the tenons will presumably fit tightly, right, so 'gap filling' is no different than the rest of the project.

[Thomas McCurnin]

Plug it, glue it, and re-mortise it.

[Jim Becker]

Plug and recut the mortise. If you are careful when producing your plug (same grain direction and same species preferred), it will virtually disappear even if exposed, and that's likely acceptable for this kind of project.

[Ken Fitzgerald]

I agree, plug and redo the mortise! In a good glue joint, the glue is often stronger than the wood.

[Patrick C Daugherty]

I would go with 3. It is just your own design detail. Only you, and everyone that reads this post, will ever know. It is also the simplest.

[Andrew Hughes]

I also would glue a tenon plug back in.
If you wanted to go fancy orientation of the grain to match. Even a plug with end grain on the face would still be strong
Good Luck

[John TenEyck]

You haven't cut the tenons in the other parts yet, right? If so, this is an easy decision. Do as most others recommend. Plug the mortise with a tenon with the grain running in the same direction and recut the mortise. When everything's done you'll have a joint just as strong as the others with no evidence of the initial oops. You can use epoxy if you prefer, but it's unnecessary if the joint fits well.

John

[Cameron Wood]

If the grain goes the same way as the tenon, it just becomes part of the tenon.