Boxland: Work Stations and Boxing Tips #2: Spline Making Jig

  • Advertise with us
Blog entry by Boxguy posted 05-12-2012 07:13 AM 12507 reads 42 times favorited 14 comments Add to Favorites Watch
« Part 1: The Glue Up Table Part 2 of Boxland: Work Stations and Boxing Tips series Part 3: Cutting Spline Slots »

The Spline Cutting Jig

I use this jig to make all my splines. Basically it is set up to use the band saw to cut triangles out of a long thin strip of wood. It is just a board with a runner for the guide slot and another board fastened at a 45 degree angle. Cutting small pieces on a table or radial saw is a disaster. Your fingers wind up in wrong places and the small pieces fly all over the shop (not good). This is a job for the band saw! If it is done well the splines will look like this…

A quick word about fit: Once you have cut a strip of wood to approximate size let’s say 1/4 inch thick by 1 inch wide by 18 inches long, you fine-tune the fit with the planer so that this strip will easily, but barely slip back and forth in the spline slots you have cut in the box. If you make this fit too tight you will have to fight the work and pound the splines into place in the slot. A slip fit lets the splines and wood swell a little with the glue. A thin bit of glue will not show, but a spline that doesn’t bottom out in the slot looks really bad when the box is finished.

Since splines are often made from expensive and rare woods, I try not to waste any of it. Why make a square spline for a triangular slot? So as you see in the picture you use the jig to cut a 45 across the strip and then FLIP IT OVER and make your next cut forming a triangle. The width of your strip really determines the size of the triangular spline. If you need a smaller spline, make your strip more narrow. Don’t try to cut smaller 45s it just doesn’t work. I usually push the strip a little beyond the blade before making the second cut so I get a flat spot at the point of the triangle. I use the flattened point to push the splines in place. It is easier on my fingers.

Any scrap will do when you are experimenting with a jig, but when I have perfected a jig I try to make a pretty one. It makes time in the shop more fun, and I can take pride in using it. This one is made from a scrap of bird’s eye maple and eucalyptus veneer.

This jig works better if it is thicker and allows the triangles to fall when cut and then be pushed slightly out of the way by the jig after you have cut through the strip. Don’t push too hard as you cut, let the blade do the work. Pushing makes the triangles fly and you want to keep the triangles on the table of the bandsaw. The rough edges of the bandsaw cuts don’t matter. You will just trim off the excess sticking out beyond the box edges with the bandsaw or sander anyhow. I use the hole in the end to hang the jig on the saw between uses.

Later I’ll show more about splines. Have fun, and keep boxing.

-- Big Al in IN

14 comments so far

View patron's profile


13722 posts in 4678 days

#1 posted 05-12-2012 08:12 AM

this is a BUENO JIG

and very nice looking too

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Roger's profile


21055 posts in 4141 days

#2 posted 05-13-2012 12:06 AM

Very kool Al. Thnx

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. [email protected]

View gfadvm's profile


14940 posts in 4027 days

#3 posted 05-13-2012 02:04 AM

Nice jig. I too cut triangular splines on the bandsaw but your jig would save me a lot of time as I have to mark each spline and then cut along the lines. Thanks for posting this.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View Philzoel's profile


303 posts in 3680 days

#4 posted 05-14-2012 03:48 PM

Big Al. How do you cut the slot for your spline? Before you glue or after and what type of jig????


-- Phil Zoeller louisville, KY

View dustyal's profile


1322 posts in 4812 days

#5 posted 08-28-2012 03:07 AM

well, don’t have a band saw…. I’ve been using scroll saw and that is a bit sloppy. I could build this jig and hand feed it since scroll saw does not have a miter slot…

thanks for the ideas… keep ‘em coming.

-- Al H. - small shop, small projects...

View The Box Whisperer's profile

The Box Whisperer

678 posts in 3407 days

#6 posted 12-09-2012 11:21 PM

any advice for the guy without a bandsaw or planer? or as I prefer to say, a tablesaw specialist? Ive been cutting little 1/2 X 1/2 X 1/8 squares on the tablesaw, making sure to protect my face very well and then sweeping up 50 or so splines off the floor…...a little ghetto, I know…..

-- "despite you best efforts and your confidence that your smarter and faster than a saw blade at 10k rpm…. your not …." - Charles Neil

View Ken90712's profile


18099 posts in 4526 days

#7 posted 02-17-2013 04:28 PM

Nice job, I make my splines both on the table saw and band saw. A zero clearance throat plate on the table saw is critical. I really like this band saw jig I’ll give this a try.

-- Ken, "Everyday above ground is a good day!"

View FrankSpillman's profile


7 posts in 4030 days

#8 posted 03-23-2013 12:00 AM

I agree totally about the band saw being best, but some people still don’t have one. I was very successful cutting splines on my table saw using a cross cut sled and a jig similar to yours, also making sure the blade just cleared the top of the wood. Just an alternative for those without a bandsaw yet.

View Boxguy's profile


2905 posts in 3604 days

#9 posted 03-23-2013 03:42 AM

Frank, Thanks for the comment. I would use a simple miter box and a hand saw before I tried working on such small pieces with a table saw. Wear a face shield and best of luck.

-- Big Al in IN

View Roger's profile


21055 posts in 4141 days

#10 posted 07-14-2013 12:24 PM

Quick & perfect.

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. [email protected]

View Jonathan's profile


45 posts in 3274 days

#11 posted 02-20-2015 08:43 AM

One trick I learned about keys, if they are slightly too thick,
Hit them with a flat face hammer, just lightly. This squishes the wood fibers just enough to slit the oversized key in the slot

-- Jhopewell, New Hampshire,

View Boxguy's profile


2905 posts in 3604 days

#12 posted 02-20-2015 02:32 PM

Jonathan, I used to thickness my corner splines so they were a tight fit and pound them in as you suggest. What I concluded was that I was working too hard and there was no room for glue. I also found that the moisture of the glue was enough to swell some woods and made putting in the splines too hard.

Now I thickness (plane) my corner splines so the wooden strip I cut into splines just barely slides back and forth in the spline slots of the box. It gives me room for glue, lets me bottom out the splines in the slots, and the job goes much faster. It is important to press the splines in place and hold them there for about a second to give the glue in the slot time to work its way out and let the spline really touch the bottom of the slot.

-- Big Al in IN

View ButchCassidy's profile


26 posts in 2595 days

#13 posted 02-21-2015 12:03 AM

Nice, I am just getting into Boxes and Pistol cases. I will steal this Great Idea (If OK) from you. Thanks for the Info.

-- " If you want your PRAYERS to be answered" get off your knees and go to work

View robscastle's profile


8349 posts in 3541 days

#14 posted 05-22-2018 10:58 PM

You know Big Al I went looking for a Spline for dummies type book, But I should have looked here first.

Thank You

-- Regards Rob

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics