First attempt - Thru Mortise (I stink at it)

  • Advertise with us

« back to Joinery forum

Forum topic by JP4LSU posted 04-17-2018 10:34 PM 2837 views 0 times favorited 7 replies Add to Favorites Watch
View JP4LSU's profile


89 posts in 755 days

04-17-2018 10:34 PM

Topic tags/keywords: mortise

So I attempted a thru mortise in some 3/4 red oak. I made a 5/16” tenon and used my dual wheel marking gage to mark out the mortise.

I chopped the mortise using a 5/16” mortise chisel. I attacked it from both sides, which is hard to screw up on 3/4” stock. The problem came when cleaning up the mortise with a bevel chisel. I wasn’t careful enough when doing this and over did it.

So now i have a red oak mortise practice piece of wood. I guess my technique on chopping needs to improve so there isn’t so much clean up to do. Then be more careful on clean up and pairing.

Also on clean up with the bevel chisel I was blowing the bottom edge out of the mortise. I’m thinking the clean up need to be attacked from both ends to keep this from happening.
Anyway. I enjoyed it and will keep at it.

7 replies so far

View Woodknack's profile


13017 posts in 2988 days

#1 posted 04-18-2018 12:02 AM

There shouldn’t be a bottom edge to chip out if you chopped from both sides. All the clean up should be inside.

-- Rick M,

View BFamous's profile


336 posts in 728 days

#2 posted 04-18-2018 01:05 AM

Practice brings you closer to perfection, but practicing on the material for your final piece brings you closer to broke…
Get some scraps and actually practice your chisel work. But first, make certain your chisels are sharp – I mean like you can see yourself in them just like a mirror, sharp. If your chisels aren’t sharp you’re going to have to put a lot of extra effort into your cuts and will be more likely to tear the wood instead of cut it.

-- Brian Famous :: Charlotte, NC ::

View chrisstef's profile


18029 posts in 3614 days

#3 posted 04-18-2018 01:05 AM

The only part that needs to look good is the first 1/8” of the mortise. Everything else can look like a beaver chewed it.

I like to take a shallow cut all the way around the edge to define the layout then pare away at it a lil bit. This will create a wall and give your chisel something to register against. Dont wail on that thing or the bevel of your chisel will push it back againt the wall you just created. Take it easy for the first little bit.

I also like to run a smaller chisel than the one thats the exact size of the mortise. Use the exact width chisel for final clean up.

-- Its not a crack, its a casting imperfection.

View JP4LSU's profile


89 posts in 755 days

#4 posted 04-18-2018 11:52 AM

Thanks guys for the tips. My bevel chisel is sharp sharp. The mortise chisel is so so. I’ll go through and sharpen my mortise chisels real good.
Chris, good idea on the wall and paring away at the lines a bit. I think Paul Sellers calls it a knife wall. He actually doesn’t even bother with a mortise chisel. He uses a bevel chisel exclusively.

I’ll keep practicing and keep at it. Having fun doing it. It will be more fun when I get a woodworking bench built.

View Robert's profile


3602 posts in 2088 days

#5 posted 04-18-2018 01:28 PM

Yes, attack from both ends. Slightly over 90° toward middle.

Establish mortise, then adjust tenon to fit, not vice versa.

You’ll get it.

-- Everything is a prototype thats why its one of a kind!!

View Stowerscw's profile


25 posts in 738 days

#6 posted 04-18-2018 02:04 PM

I agree.

There shouldn t be a bottom edge to chip out if you chopped from both sides. All the clean up should be inside.

- Woodknack

View JP4LSU's profile


89 posts in 755 days

#7 posted 04-18-2018 02:28 PM

Thanks rwe2156, that’s good advice. I think my next try will be much better if I follow everyones advice. Growing pains.

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