repair advice for busted up miter keys

[earnest nacelle]

Hello folks - new here, enjoying reading through everyone's questions and good advice! I could use some...

I did a suboptimal job paring down the cherry miter keys (on a clear maple decorative painting frame) with my bench chisel - went for too much too fast - and now the corners of my keys are varying degrees of chewed and not flush with the outside of the miter.

Any tips for fixing/patching/masking the outside (corner) of a miter key?

I've patched miter keys before using the sawdust and glue mixture method, but for a few reasonsI don't think this will work for these corners.

Conversely, there's potentially too little material to patch with a supplemental key, though I suppose if I cleaned up the chewed up fibers and make a flat edge for the new key to adhere to this might actually be a clean solution, albeit a time consuming one.

I will share some photos in the morning but wanted to get this out while it's top of mind.

Thanks very much in advance...

[crimson terrace]

Have you got:
1- A photo or two
2- An indication of what tools you have available
3- An idea of how experienced you are so folks don't confuse/patronise by mistake! 🙂

I likely can't help you, but the above will certainly help someone who can.

[carmine grove]

By "keyed miter joint" are you referring to cutting a slot through the corner and inserting a spline?

If yes - and assuming you cut your slots with a table saw and jig - if you really messed up trimming the spline you can always re-cut them and put a whole new spline in. You may need to make it a little wider to make sure you get rid of all of the old spline.

If no - pictures would help a lot. 🙂

[earnest nacelle]

Yes!

Here is each corner roughly worst to least bad

[carmine grove]

Well then, my advice stands... just remove the broken splines with the same tool you used to make the grooves in the first place - I'm assuming table saw and jig - then replace them.

I trim mine using a flush cut saw taking my time to not break them. I then sand the remaining nub flush. If you use a hand plane or a chisel make sure they're super sharp and the force you are putting on the spline doesn't go towards the "open" end so your cuts are back up by wood.

Other people with more experience may offer you better/different advice but this would be my approach.

[earnest nacelle]

Appreciate it @carmine grove !

I need to pick up a flush cut daw. I used a ryoba saw and was trying to avoid cutting in to the maple so I left the remainder way too proud!

So getting this back onto the table saw is not optimal. I live and work at a shop in Brooklyn and want to avoid lugging the frame back and forth from the shop on the subway again

But it's an option!

Any thoughts on smoothing down the corners with a bench chisel and just adding another mini-spline? I guess the downside could be a weird visual effect. Anything else I'm not seeing of as to why this wouldn't be a workable solution?

[crimson terrace]

A ryoba will flush cut ok but I think you overlooked your grain direction and got hasty

No pressure when sawing, basically :/

[carmine grove]

Well... I suppose it should be theoretically possible to shave down your splines and clean up the glue if you have a narrow enough chisel and are super careful.

My concerns with that approach would be:

• damaging the frame
• the new spline being too fragile and also breaking
• weird gaps in fitment
• the weird visual effect you mentioned

Unfortunately I don't have any other ideas for you.

Well, that's not exactly true... You could use an Uber or taxi to avoid taking the subway. 😉

Hopefully someone else on here will have a better solution and we will both learn something.

[bold cosmos]

What’s the goal? The “outside corner” bit I’m not quite tracking. There’s issue in the poplar (?) and the splines, just trying to make sure we’re on the same page for objective

[earnest nacelle]

The splines are the primary issue - how best to repair the corners so they are 90. The damage to the maple is a separate issue I'll have to solve next !