45 degree mitre joinery problem

[scott vroom]

We're having a problem solving a 45 degree miter joinery problem. We're trying to join 2 pieces of 3/4" x 2" wide x 36" long pieces of poplar, each cut at a 45 degree angle along the 36" lengths, to form a 90 degree corner. Attached is picture of some sample pieces held by my son to give you a visual idea of what we're doing. We want the outside corner join to be very tight, ideally pulled together tightly using screws. Problem is the Kreg system will not work in this application (by their own admission and our failed efforts). The trick is we're trying to avoid any evidence of joinery on the outside facing sides and are looking for a way to secure the two long boards tightly together with inside angle joinery (screws etc). Take a look at the pic and let me know of any ideas that come to mind.

Thanks!

Scott and Cory Vroom

[Brandon Weiss]

Would biscuits work in this application? The would at least guide the alignment while you either clamp and glue or install an angle with screws to the inside.

[Ken Shoemaker]

I got the same thing coming up... I think I'll try a lock miter router bit. I'm told they are a beeee aaaach to set up, but when you get it, it works well....

Ken

[Joe Leigh]

Splines cut vertically into the miters would work.

[Dan Bowman]

A spline works well and if you don't mind it showing on the ends, is real easy to cut on the table saw set at the same 45 angle.

[glenn bradley]

Splines. Splines in stopped dados if you don't want them to show.

[Vince Shriver]

MCLS has a video that shows one of their bits made for this exact application (biscuits). Also, what the guys already said about splines.

[phil harold]

I got the same thing coming up... I think I'll try a lock miter router bit. I'm told they are a beeee aaaach to set up, but when you get it, it works well....

Ken

+1 on this idea
takes little tweaking during set up but makes a breeze during glue up

[Jeff Monson]

Dont know if you have access to one but a domino cutter absolutely shines on this joint.

[scott vroom]

Splines or biscuits are a good idea to maintain alignment, but I still have the problem of how to "pull" both sticks together at the miter to form a very tght, seamless joint, keeping in mind this is a 36" long joint. Are there specialty clamps or jigs that might help?

Thanks....keep the suggestions coming!

[Mike Henderson]

I use biscuits in that application. Then, I use two clamps, one pulling each way. 36" isn't that long for clamps. Here's a bad picture of a miter joint I did with biscuits.

Just as a side note, notice how the grain runs around the corner. I point that out because no one ever seems to notice it on the finished piece.

Mike

[Larry Fox]

Dont know if you have access to one but a domino cutter absolutely shines on this joint.

+1 here.

http://www.sawmillcreek.org/showthread.php?t=125425

The cabinet in this thread has a very long miter joint running from the bottom to the top (the joint between the side and the top). If I understnad you correctly this is exactly what yo are trying to do. I shot a few Dominos into it for alignment and glued it. I used packing tape instead of clamps and it worked fantastically. Trick I have found with miters (and this sounds obvious) is to make sure that your saw is cutting dead-bang at 45-degrees. For smaller joints like the one you show in the pic you can tune them on the shooting board to get them right.

[Bill Huber]

Don't know if this will help on the glue up or not but here goes.

Lay them down on the bench with the bevel down and the edges meeting. Then use painters tape across the edge every few inches, you want the edges to be tight together.

Turn it over apply the glue and then fold the to parts together and use a clamp or more tape to hold them.

This really works great with boxes so I don't see why it would not work for this.

[Bob Lang]

Why complicate a simple process? You're trying to glue two long grain edges together, and glue alone will do. Lay the two pieces face up on a flat surface with the points of the miters touching. Place a few strips of clear packing tape across the two, and use pressure on the tape to pull them together. Run a strip of tape lengthwise along the joint, forming a hinge and flip the pieces over so they are now face down. Put some glue on the mitered surfaces and fold the joint closed, then wrap tape around the assembly to hold things together while the glue dries.

If the pieces are straight, this is quick and easy. If the pieces aren't straight, no amount of screwing, splining, dominoing or lock mitering will bring the joint closed.

Bob Lang

[Lee Schierer]

Don't know if this will help on the glue up or not but here goes.

Lay them down on the bench with the bevel down and the edges meeting. Then use painters tape across the edge every few inches, you want the edges to be tight together.

Turn it over apply the glue and then fold the to parts together and use a clamp or more tape to hold them.

This really works great with boxes so I don't see why it would not work for this.

Instead of painters tape use strips of the nylon reinforced tape perpendicular to the joint line. It hold better. Once you apply the glue and fold the joint closed you can carefully apply C-clamps running each way to pull the corner together tight. Make sure your pieces dry fit together well. If you can't close the gap with your hands you never will with tape or clamps. There is no need for screws once the glue dries as that is essentially a face grain joint and it will be stronger than the wood itself. Don't use duct tape as it may leave a residue behind if left on the wood very long.

[scott vroom]

Thanks for the great ideas.

Looks like I need to get educated on Domino joinery....seen lots of references to it on this forum but not familiar with it. One challange in clamping up a miter joint is to prevent the pieces from "slipping" as clamping pressure is applied. Seems that using biscuits or dominos(?) could provide the stability to allow clamp pressure to pull the joint tightly together while preventing the slippage.

I checked into Ken's suggestion on the Lock Miter Joint.....it looks like a pretty bullet proof method to join 2 mitered surfaces. I found this vid on Youtube...I hope zi'm not getting into trouble with SMC mgmt...I truely have no stake in the company that published the video. Ken, notice the plastic set up block the guy uses to set the router bit height. This seems to solve the "difficult setup" problem you flagged. Wow, this joinery looks awesome!

http://www.youtube.com/watch?v=POvBhQo2ivQ

Thanks to all....as always, I keep-a-learning on the 'creek.

[Rick Moyer]

Never did it yet on long stock, but I agree why complicate it; use tape as suggested above to secure and pull the seam together. I would say either the nylon strapping tape or clear packing tape. of course I don't have a lock mitre bit yet, either.

[Ken Shoemaker]

Scott,
Thanks for the video. I've never seen it before.

Just a warning. They don't mention it, but it is absolutly critical that the wood to be joined is EXACTLY the same thickness. Any deviation and your hosed.

Ken

[Dave Anthony]

I agree with what others have said - glue and tape are sufficient. As long as the stock is straight and you cut a clean 45 degree angle you should get a clean joint. You can cut 1 45 and flip one piece, or for a better grain match cut 2 45's. The front edge of the cabinets in each of these threads use this method:
http://sawmillcreek.org/showthread.php?t=112095
http://sawmillcreek.org/showthread.php?t=119905

[Chris Padilla]

Scott,

Long-grain to long-grain joints with glue are incredibly strong.

I have no issues if you want to add biscuits or splines or dowels or dominos but keep in mind that while they can be great alignment aids, they can also be frustrating MISalignment aids! :)

[Joe Wiliams]

Just as a side note, notice how the grain runs around the corner. I point that out because no one ever seems to notice it on the finished piece.

Mike
Very nice!:cool:

I'm one of those who notices and appreciates that kind of detail:)