Mitred corner splines - Why?

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by KnickKnack posted 08-11-2012 04:19 PM 1885 views 0 times favorited 7 replies Add to Favorites Watch
View KnickKnack's profile


1094 posts in 3772 days

08-11-2012 04:19 PM

Topic tags/keywords: splines question

I’m building my very first “thing” (it’s not a box, but if you think box you’ll be fine) using pure 45° joints. And, of course, I’m thinking of deploying splines like this…

(this image nothing to do with me, just copied from here)

I understand the need for, and the potential beauty of, the splines – this isn’t my question.

Every video I’ve ever seen, every book I’ve ever read, every blog I’ve ever digested, every jig I’ve seen about adding these splines consists of …
  1. Glue box together
  2. Holding your piece at 45° with some form of jig, cut the slots for the splines
  3. Add splines

I don’t have a table saw, and, even if I did, us Europeans aren’t supposed to make that kid of cut, so I’m going to be doing it with my 45° jig on the router table – basically a similar idea as with a table saw.

I can, and have, loaded the two pieces that will go together into my jig, before I’ve glued the thing together. Applying only brain cells and zero actual experience to this problem, I can’t see what might be wrong with cutting the slots first. If anything, it seems this will help me when I glue the things together – at least the joints won’t be able to slide sideways.

However, it’s late so “work” is suspended for today, and I thought I’d ask – any reasons not to cut the spline slots first?

Thanks in advance.

-- "Do not speak – unless it improves on silence." --- "Following the rules and protecting the regulations is binding oneself without rope."

7 replies so far

View ShaneA's profile (online now)


7055 posts in 2804 days

#1 posted 08-11-2012 04:34 PM

I have only done it on a TS with the joint(s) already glued, I have seen it done with a hand saw as well. Never tried it before gluing, but I guess if you keep everything perfectly aligned, you would be ok, but it would have to be dead on.

View Nicky's profile


695 posts in 4297 days

#2 posted 08-11-2012 04:41 PM

Cutting the slots first can be done, just need to be very precise. You also risk a greater chance for tear-out of the end grain fibers.

Cutting slots after the miter is glued gives you a better chance at a perfect fit for your splines and less of a chance for tear-out.

I’ve installed the splines with nothing more then a small handsaw.

-- Nicky

View Woodwrecker's profile


4203 posts in 3781 days

#3 posted 08-11-2012 05:20 PM

Shane & Nicky have both hit the high points.
(Plus, I think it’s just easier doing it after the glue up.)

View NormG's profile


6283 posts in 3209 days

#4 posted 08-11-2012 05:28 PM

They may not line up and then you have additional choices to make

-- Norman - I never never make a mistake, I just change the design.

View Gene Howe's profile

Gene Howe

11079 posts in 3634 days

#5 posted 08-11-2012 06:05 PM

Why not use a dovetail bit to cut your slots?
As to cutting them first, I see no advantage.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View a1Jim's profile


117342 posts in 3783 days

#6 posted 08-11-2012 06:13 PM

We all do things in our own way so get it a try and see what you think. My guess is it’s easier once the boxes are put
together. That’s the way I have done it, but what ever floats your boat.:)) You are great at making very unique projects so I anxious to see what you come up with.

-- wood crafting & woodworking classes

View Dustmite97's profile


439 posts in 3426 days

#7 posted 08-11-2012 10:37 PM

I have had my nightmares with splines. I have tried cutting them first but wasn’t careful enough and wrecked the wood. I have only ever completed one box with splines. I cut them with the miter joints already made. They can be done first but I agree with Nicky, you have to be very careful. Good luck and I’m looking forward to see how it all turns out :)

Have your say...

You must be signed in to reply.

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