A method of mortising

[Jim Koepke]

Very Nice

jtk

[Rob Luter]

Completed 8 hand chopped mortises, then 8 hand sawed tenons. Edge jointed top for 36 by 48 table in Pennsylvania cherry. Donated table to Landis Valley Museum Harvest Days Auction coming October 7 & 8 near Lancaster Pennsylvania.

Attachment 507473Attachment 507474

Showoff.

Just kidding. That is really nice.

[Mark Rainey]

Very Nice

jtk

Thanks Jim!

Showoff.

Just kidding. That is really nice.

Thanks Rob!

[Mark Rainey]

Hand chopping more mortises. Sometimes, even when I stay exactly between my mortise gauge lines, I can get tearout along the edge. I tried knifing the lines but still I can get tearout. Usually the shoulders will hide the tearout. Perhaps I am chopping too aggressively. Does any else experience this & are there any solutions❓

IMG_5166.jpegGood


IMG_5167.jpgBad

[Jim Koepke]

That looks like it has more to do with the wood's grain than it does technique.

jtk

[Warren Mickley]

Hand chopping more mortises. Sometimes, even when I stay exactly between my mortise gauge lines, I can get tearout along the edge. I tried knifing the lines but still I can get tearout. Usually the shoulders will hide the tearout. Perhaps I am chopping too aggressively. Does any else experience this & are there any solutions❓

When we make a mortise we cut the fibers across the grain and depend on the fibers on the side walls to slide along the grain to complete the cut. We don't really cut the sidewalls. Because we cut bevel down, the chisel also slides along the side grain and, if the corners are sharp, will scrape the side walls and tidy them up a bit,
.
If the grain is somewhat crooked, the slippage at the sides does not work so well. Usually we take considerably smaller bites when chopping, which helps a lot.

The straightness of the grain is a consideration when choosing stock for members to mortised. Sometimes, as for a table leg, we position things so the section with the mortise is particularly straight grain. Sometimes we might choose curly grain for the stiles of a frame, knowing that the mortising will be more work. The straightness of the grain also affects the strength of the joint: the mortise and tenon joint is designed with grain orientation in mind. Grin runout can result in joint failure many years later.

[Mark Rainey]

That looks like it has more to do with the wood's grain than it does technique.

jtk

Thanks Jim, I think you are right

[Mark Rainey]

When we make a mortise we cut the fibers across the grain and depend on the fibers on the side walls to slide along the grain to complete the cut. We don't really cut the sidewalls. Because we cut bevel down, the chisel also slides along the side grain and, if the corners are sharp, will scrape the side walls and tidy them up a bit,
.
If the grain is somewhat crooked, the slippage at the sides does not work so well. Usually we take considerably smaller bites when chopping, which helps a lot.

The straightness of the grain is a consideration when choosing stock for members to mortised. Sometimes, as for a table leg, we position things so the section with the mortise is particularly straight grain. Sometimes we might choose curly grain for the stiles of a frame, knowing that the mortising will be more work. The straightness of the grain also affects the strength of the joint: the mortise and tenon joint is designed with grain orientation in mind. Grin runout can result in joint failure many years later.

Thanks Warren. Grain selection is important. I will try smaller chops when dealing with crooked grain.

[steven c newman]

I usually hit the chisel 1-3 times, depending on the wood being mortised. The only time I have that sort of tear-out...is when I am clearing the chips out.
A Chopping Day, 5 done .JPG

Now, IF the grain is turning across the mortise....I will take a wider chisel and do a tap or 2 on the wall's lay-out line..cutting the grain's path across the mortise. Does not take much, other than the wise chisel being sharp

A Chopping Day, 1st one done.JPG

[Mark Rainey]

I usually hit the chisel 1-3 times, depending on the wood being mortised. The only time I have that sort of tear-out...is when I am clearing the chips out.
A Chopping Day, 5 done .JPG

Now, IF the grain is turning across the mortise....I will take a wider chisel and do a tap or 2 on the wall's lay-out line..cutting the grain's path across the mortise. Does not take much, other than the wise chisel being sharp

A Chopping Day, 1st one done.JPG

Good suggestion Steve…I also get the problem mostly when leveraging the chips out.

[Jim Koepke]

Good suggestion Steve…I also get the problem mostly when leveraging the chips out.

That is where a lock mortise chisel comes in handy. Use a size smaller than the mortise if available.

Swan Neck:Lock Mortise Chisels.jpg

A sharp edge at the end helps to clean up the bottom of a mortise.

jtk

[Mark Rainey]

That is where a lock mortise chisel comes in handy. Use a size smaller than the mortise if available.

Swan Neck:Lock Mortise Chisels.jpg

A sharp edge at the end helps to clean up the bottom of a mortise.

jtk

those are nice Jim - I will keep my eyes open for a reasonably priced used one.

[Jim Koepke]

those are nice Jim - I will keep my eyes open for a reasonably priced used one.

The small one is ~1/8" and may have come in a Buck Bros. carving kit. They show up occasionally at yard sales.

The other was purchased from another SMC member. There is also a 1/2" Marples made one in the shop for big work.

jtk

[Christopher Charles]

Great looking table Mark. I agree that hand mortising for a table is nothing to be afraid of and can be faster (and less scary) than mortising with, say, a router.

A bit off-subject, but how did you attach the top to your table(s)?

[Mark Rainey]

Thanks Chris! I used the figure 8 table top connectors. I really like them. Not historically accurate, but very convenient. Are you familiar with them?

Great looking table Mark. I agree that hand mortising for a table is nothing to be afraid of and can be faster (and less scary) than mortising with, say, a router.

A bit off-subject, but how did you attach the top to your table(s)?