# How do I cut full blind splined mitres?



## rolandstronghammer (Jan 15, 2016)

The title says it all. I dont have a Festool Domino so im not sure how to do this otherwise and accurately. It needs to be precise so that the mitre edge is clean.

Something like this










The only thing I can find is this jig which is something that could be manipulated so that the router bit cuts into the center of the miter. Then I can clean up the edges with a chisel and install the spline.


----------



## Picklehead (Feb 12, 2013)

Biscuit joiner.


----------



## rolandstronghammer (Jan 15, 2016)

> Biscuit joiner.
> 
> - Picklehead


I'd prefer a spline because biscuits are a bit weak for the application. Not to mention a biscuit joiner is $100.


----------



## bandit571 (Jan 20, 2011)

Hammer and chisel..









Closed up to make this..









Top and bottom of the joint look like a simple miter joint…









Full Blind mitered Finger Joints…


----------



## rolandstronghammer (Jan 15, 2016)

> - bandit571


That would be perfect but i don't have the skills to do something like that at this point. Also, the miter has to be perfect and i think in order for this to come out clean you need to have done it plenty of times. Perhaps this is easier than it looks because it looks quite hard.


----------



## johnstoneb (Jun 14, 2012)

I understand you don't have a biscuit joiner but biscuits in this application would be just as strong as a spline. a router would probably do what you want, Can you use dowels?


----------



## rolandstronghammer (Jan 15, 2016)

> I understand you don t have a biscuit joiner but biscuits in this application would be just as strong as a spline. a router would probably do what you want, Can you use dowels?
> 
> - johnstoneb


Yes dowels would work but how do I drill them at a 45 degree angle.


----------



## builtinbkyn (Oct 29, 2015)

You can make that cut on your table saw. However it obviously needs to pass thru the top and bottom edges of the boards, which will expose the miter. I guess it would be possible to use the same species for the spline and that would somewhat camouflage the spline. The alternative would be to band the top and bottom edges with the same species, to conceal the spline.


----------



## rolandstronghammer (Jan 15, 2016)

> You can make that cut on your table saw. However it obviously needs to pass thru the top and bottom edges of the boards, which will expose the miter. I guess it would be possible to use the same species for the spline and that would somewhat camouflage the spline. The alternative would be to band the top and bottom edges with the same species, to conceal the spline.
> 
> - builtinbkyn


I'd like it to be hidden. This would definitely work but i really do want it fully blind.


----------



## bandit571 (Jan 20, 2011)

That WAS the first time I tried that joint.

I did post a blog about it, BTW. "Hidden Finger Joints" I think was the title…

Really not that hard to do, depends on how well you can handle a small saw, a chisel or two, and do a layout.


----------



## 000 (Dec 9, 2015)

I didn't see how wide your piece is?
You could clamp the piece to your table saw fence and raise the blade, making sure the piece is centered so that you don't come out the front or back. Move the fence and do it a second time if you want a fatter cut.
Then make 1 big football/sawblade shaped spline to fill it.

*NOTE: My saw doesn't come straight up. 
You would have to raise the blade to the height you want, and then make your marks where to put the piece on your fence.


----------



## duckmilk (Oct 10, 2014)

> You can make that cut on your table saw. However it obviously needs to pass thru the top and bottom edges of the boards, which will expose the miter. I guess it would be possible to use the same species for the spline and that would somewhat camouflage the spline. The alternative would be to band the top and bottom edges with the same species, to conceal the spline.
> 
> - builtinbkyn


This would work. Mill the pieces slightly wider than needed, rip a thin veneer off of each edge, cut the slot on the table saw, glue the cut off veneer pieces back on. Should be virtually invisible.


----------



## bandit571 (Jan 20, 2011)

Router table?

Cut your miters first. Install a bit the correct size for the spline. Establish a start and stop point on the fence, set the fence to where the slot is centered in the end of the board. Cut will be a plunge cut. Plunge down at the start point, slide over to the stop point.

You might rig up a sled to hold the piece at the 45 degrees needed, and have it so you can slide the part onto the bit to start the cut. When you reach the end of the cut, you can slide the piece either back a bit, or shut off the router, and remove the finished piece.


----------



## rolandstronghammer (Jan 15, 2016)

> I didn t see how wide your piece is?
> You could clamp the piece to your table saw fence and raise the blade, making sure the piece is centered so that you don t come out the front or back. Move the fence and do it a second time if you want a fatter cut.
> Then make 1 big football/sawblade shaped spline to fill it.
> 
> ...


Its roughly 2ft wide so this would work. not sure how to control the height of the blade so that the depth is consistent on both cuts.


----------



## rolandstronghammer (Jan 15, 2016)

> Router table?
> 
> Cut your miters first. Install a bit the correct size for the spline. Establish a start and stop point on the fence, set the fence to where the slot is centered in the end of the board. Cut will be a plunge cut. Plunge down at the start point, slide over to the stop point.
> 
> ...


That's what i was thinking except the pieces are too large to be held up at a 45 degree angle. I think i'd need to hold the router at a 45 degree angle and use a template and a straight bit to cut the spline slot.


----------



## builtinbkyn (Oct 29, 2015)

If the pieces are that wide, you can make the cut on your TS with stops. Then you have two choices as I see it - 1. make a spline and then taper the ends to match the blade cut. 2. clean out the rest of the cut with a chisel. Obviously you'll need to test this all on scrap


----------



## Loren (May 30, 2008)

There's no easy way to do it on a 2' wide
workpiece I know of. You're better bets
are an elaborate router jig or the table saw.

If you can accept ripping the ends off
and regluing them back on after cutting
a through slot on the table saw, then the
problem of how to make a stopped cut
on the saw is not a problem.


----------



## TungOil (Jan 16, 2017)

A hollow chisel mortiser with a tilting table, or a JDS multi-router would be my choice for that cut. Both are really expensive. Perhaps one of your WW buddies has a mortiser you can get some time on? Short of those tools, I think your original idea is likely the best bet to get an accurate, clean mortise.


----------



## Loren (May 30, 2008)

Also, a 24" wide miter on end grain can be
really tricky to get fit right. If you're supposing
you can just tilt your table saw blade and 
use a cut off box to cut them and it will
all go together nicely, you may be surprised.


----------



## BLarge (Aug 29, 2011)

> Router table?
> 
> Cut your miters first. Install a bit the correct size for the spline. Establish a start and stop point on the fence, set the fence to where the slot is centered in the end of the board. Cut will be a plunge cut. Plunge down at the start point, slide over to the stop point.
> 
> ...


Yep, I'd rig up a 45 degree jig with handles toward the back (to protect the hands), with a few sturdy hold-down clamps, maybe glue some sandpaper where the piece will sit to insure it doesn't move. I'd put in start and stop blocks to safely enter the cut, and use a simple 1/4 slot cutter to pop in the slots. The jig will take a while to design and build, and the cuts should be really quick. Good news is, this jig can be stored and used for years.

you could also rig up a jig for a plunge router and collett- I honestly hate using a router free hand, but this depends on your comfort level- but I would make that jig very study and well thought out- safety first.


----------



## builtinbkyn (Oct 29, 2015)

This seems to be way overthought. It's a shallow cut that can be accomplished with a single dado blade on the table saw. If the boards are 2' wide, cut them oversized - maybe 26". Make a plunge cut to start the kerf and run it to an equal distance at the other end. Mark those start and stop points on the fence. Do all four the same then cut the boards to the 24" size leaving the ends intact. Square up the kerf with a chisel or router plane. Not knowing the thickness of the stock, the kerf more than likely won't be deeper than 1/2". Not a lot of clearing out to do. Obviously test this method to ensure you can get good alignment of the splines and tight miters.


----------



## runswithscissors (Nov 8, 2012)

If you do decide to make the mortises with a router, why bother to square up the corners of the mortise? Much easier to simply round the edges of the spline. It's not going to show.


----------

