In my opinion, one of the most difficult joints to make is a miter joint. Although they are very attractive, they have almost no inherent strength, and require a high degree of accuracy to get all four corners of a box or frame to meet without gaps. To ensure that they remain closed, I use a spline of some design to strengthen the joint.
A number requested additional information on the Miter Spline Jig I use when making boxes. I can’t take credit for the design of this jig, but for the life of me, I can’t remember where I got the idea; perhaps a magazine or maybe a woodworking buddy.
It’s very simple in concept; a carrier that allows me to pass the mitered corner of a box or box lid over the table saw blade at 45 degrees. I think the close-up pictures speak for themselves. The jig is crudely made, but the right-angle is dead accurate. I’ve been using this for about four years. Perhaps someday I will make one that looks like it belongs in Shop Notes; NOT. LOL



Here I have just cut two spline slots in the four corners of the previously glued up box body. The blade is tilted to ten degrees and the box was flipped so that the slots angled in opposite directions. The splines will be cut from American Maple and will be one saw curf wide. I will also use American Maple to make the trays that will fit into the box – but that’s a few blogs away yet.

A close-up of the spline slots.

-- CanuckDon "I just love small wooden boxes!" http://www.hillsbiblechurch.org/

















25 comments so far
MsDebbieP
home | projects | blog
18328 posts in 2356 days
#1 posted 2135 days ago
it looks so simple
-- ~ Debbie, Canada (http://www.execulink.com/~yohan)
Lee A. Jesberger
home | projects | blog
6524 posts in 2175 days
#2 posted 2135 days ago
Don;
From these angles, it’s easy to see. In the earlier photo, it looked like the box would be several inches from the saw table. Had me bewildered.
Thanks for posting this!
Lee
-- by Lee A. Jesberger http://www.prowoodworkingtips.com http://www.ezee-feed.com
TomFran
home | projects | blog
2934 posts in 2190 days
#3 posted 2135 days ago
Don,
Thanks a lot for your willingness to share your knowledge. The pictures are very helpful.
Isn’t it amazing that some of our jigs, although not very attactive, do an amazing job at their intended purpose?
-- Tom, Surfside Beach, SC - Romans 8:28
PanamaJack
home | projects | blog
4472 posts in 2273 days
#4 posted 2135 days ago
Great pictorial Don. Another great blog.
-- Carpe Lignum; Tornare Lignum (Seize the wood, to Turn the wood)
Thos. Angle
home | projects | blog
4400 posts in 2158 days
#5 posted 2135 days ago
Don, Thanks for sharing. Seems the first of these I saw was in R. J. DeChristophoro’s Book “The Complete Book of Power Tools” I see no reason that our jigs need to look like our furniture. They only need to be functional. Most I use once or twice and that’s it. Your box works very well and that is what you expect from it. Keep going with these boxes, Don, because I just happen to LIKE little wooden boxes alot too.
-- Thos. Angle, Jordan Valley, Oregon
Joel Tille
home | projects | blog
213 posts in 2440 days
#6 posted 2135 days ago
thanks for the closeups. This could be in shop notes, in the shop it’s all about fuctionality not the beauty, that is what should be the end product. Of which you have many great examples.
-- Joel Tille
mot
home | projects | blog
4912 posts in 2232 days
#7 posted 2128 days ago
Well, that clears that up! Thanks for the post Don! Great tutorial. (subliminal CSS plug being sent down under)
-- You can discover more about a person in an hour of play than in a year of conversation. (Plato)
Brad_Nailor
home | projects | blog
2450 posts in 2153 days
#8 posted 2117 days ago
Great jig. Who cares what it looks like..if it does what its supposed to do its awesome! I am going to build one just like it! I love miters and I like the splines for decorative more than structural purposes. I love the angled effect too..a little tweak that makes all the differance in the beauty of the finneshed piece!
-- http://www.facebook.com/pages/DSO-Designs/297237806954248
Hawgnutz
home | projects | blog
526 posts in 2272 days
#9 posted 2107 days ago
Very nice jig, Don. Looks better than soem of my jigs….LOL As long as they get eth job done, who is gonna look at em, anyways!
Gonna have to make me one, too.
God Bless,
Hawg
-- Saving barnwood from the scrapyards
Andy
home | projects | blog
1337 posts in 2104 days
#10 posted 2096 days ago
Don, what type of blade do you use for cutting splines slots? I use a standard ATB saw blade which means the bottom of the kerf is not flat.I then use the edge of a file to clean them up. Tedious and not consistant results. I am thinking about getting a flat top grind ripping blade which will make a perfectly flat bottomed kerf.Whats your thoughts.Thanks in advance.
-- If I can do it, so can you. www.artboxesbyandy.com
CharlieM1958
home | projects | blog
14932 posts in 2414 days
#11 posted 2096 days ago
So many jigs…..so little time.
-- Charlie M. "Woodworking - patience = firewood"
CharlieM1958
home | projects | blog
14932 posts in 2414 days
#12 posted 2096 days ago
BTW, this may be (read: probably is) a dumb question, but I noticed the spline cuts don’t seem to be perpendicular to the box side. Is this an appearance choice, or is that part of what adds extra strength to the joint?
-- Charlie M. "Woodworking - patience = firewood"
Don
home | projects | blog
2592 posts in 2373 days
#13 posted 2096 days ago
Charlie, there are no dumb questions, only dumb answers. I hope this answer doesn’t sound too dumb.
It’s simply a design choice. I like the look, but my wife doesn’t. I can only hope that my client does.
-- CanuckDon "I just love small wooden boxes!" http://www.hillsbiblechurch.org/
Don
home | projects | blog
2592 posts in 2373 days
#14 posted 2096 days ago
Quote Andy: ”Don, what type of blade do you use for cutting splines slots?”
Andy, I have the same problem. I use a very narrow and sharp chisel to flatten out the bottom of the slot.
I, too, find this less than fully satisfactory. I plan to purchase a cheap saw blade and have it ground flat for this purpose. It will only get occasional use, so I don’t think that I should be necessary to spend good money for the blade.
-- CanuckDon "I just love small wooden boxes!" http://www.hillsbiblechurch.org/
Krisztian
home | projects | blog
89 posts in 2095 days
#15 posted 2093 days ago
Very nice jig,Don.I need to make one,just like yours.
-- Krisztian VA My website: www.vacarpentry.com
View all comments »
showing 1 through 15 of 25 comments
Have your say...