Mortise wall smoothness question

[Phil Mueller]

Thank you for sharing that link, Stewie. It seems nothing has changed much in the exchange of opinions...just the medium.

[Brent Cutshall]

Now, as for QUIET, I think mortising is the most neighbor-annyoing operation you could perform, power and hand tool ops inclusive.

Dern mortises, noise makin' critters. My brother always finds somewhere else to work when I'm mortising (auto-correct keeps trying to replace my words). Plus one on drilling the mortise, that's what I do.

[Prashun Patel]

Sorry Stewie, I forgot about through mortises.

[Patrick Chase]

Although PVA glues are not "gap" filling, one has to define exactly what is a "gap". IMO you would have to have an extremely loose very poorly made joint for the glue to fail.

IIRC (though I can't find a reference) PVA wood glue retains a decent fraction of maximum strength up to about 10 mils (~0.25 mm) of clearance. It goes downhill rapidly from there, though.

EDIT: Franklin recommends 2-6 mils of clearance for "commonly used wood adhesives", which is broadly consistent with my recollection.

[Patrick Chase]

Could it be that something machined like domino mortise would make a stronger joint because of the smooth surfaces? Still debating internally power/hand tools dilemma.

If you look closely at Dominos you'll notice that their surfaces are intentionally patterned to prevent squeeze-out and allow air to escape from the joint when it's assembled. Ditto for biscuits and most joinery dowels. Smoothness is unneccessary and can be a liability.

[steven c newman]

About like those videos from GE HONG? He sit on a sawbench. Or rather sits the board on the bench, adds a towel to sit on the wood with. Can chop a through mortise in about the time it took to type this out...

[Brian Holcombe]

I can chop a normal mortise in hardwood in about 4 minutes, taking an easy pace....but I can't do that quietly which is the problem at hand.

[glenn bradley]

Could it be that something machined like domino mortise would make a stronger joint because of the smooth surfaces? Still debating internally power/hand tools dilemma.

If you look closely at Dominos you'll notice that their surfaces are intentionally patterned to prevent squeeze-out and allow air to escape from the joint when it's assembled. Ditto for biscuits and most joinery dowels. Smoothness is unneccessary and can be a liability.

Lots of room for opinions on this. If you talk to PVA adhesive makers (a pretty common glue for many of us), smooth mating surfaces are desired. Glues that bind by absorbing into the material work best if the materials meet well. As mentioned dowels, biscuits and dominos have texture to avoid hydraulic lock and possibly for other reasons where pro shops use HiPUR polyurethane glues and the like that gap-fill to some extent. I cut a groove on each side of the shop made floating tenon stock I make for just this reason although the great majority of the tenon is face grain to mate with the mortise walls.

Although the discussions on the validity of wood joint tests are plentiful in themselves, dowels, biscuits and dominos test to failure at lower levels than floating M&T, M&T, Bridle joints and so forth. Some tests take the time to test varying dimensions of M&T and show optimal sizes for different scenarios. The point is that you can over think a lot of things to a degree beyond the benefit of the analysis. A domino is about half the strength of a well proportioned M&T but, if the domino is plenty strong, how much does the number really matter?

[Derek Cohen]

Is this thread about making mortices as quietly as possible? Or is it about whether smooth walls are necessary?

The latter is easiest to answer - "smooth" is a relative statement anyway. Off a mortice chisel, the walls are "hairy", and this works. Off a bench chisel the walls will be smoother. This works as well.

I thought the big issue was the noise factor. If so, the last thing you want to do is wack a chisel into wood, especially a work piece clamped to a bench top. That is NOISY! I have a Thor plastic headed hammer, which is relatively quiet .... a lot quieter than my wooden mallet. I use it when I need to keep sound levels down, and my gennous are going to disturb the family. But the Thor is still too loud for neighbours in an apartment next door.

Talk about how to cut a mortice - for example, straight down vs a V - totally misses the point here. The point is that one cannot chop at all. Forget chopping.

If you have a quiet drill press, drill out the waste with a forstner bit. This is the best of all since you can overlap the holes (which you cannot do with other drill bit types). If you cannot use a drill press, use a brace-and-bit, and pare away the remainder. You will need a few chisels, working from narrow to wide. This is where paring chisels come into their own.

Regards from Perth

Derek

[Eric Brown]

If you can find a brace type Forstner bit you can overlap holes which can remove more material quietly.
After boring you can clean up with chisels.

[Brian Holcombe]

The quiet method can also make smooth walls.

[Andrey Kharitonkin]

Thank you, gentlemen! Your replies gave me several interesting ideas!

Smoothness and quietness become connected in my mind because if it appears not smooth and then not quiet then why not use not quiet power tools for shorter time and at least have smooth and perpendicular walls. Both aspects interest me. Apologies for confusing title.

Perhaps, doing some chopping outside is a good idea for summer, like Prashun suggested.

Maybe drilling out some of the waste and then using shoulder technique can give better mortise wall. What I mean is not to drill close to the walls, but more away from them. And then use chisel like there would be no holes by pushing it instead of hammering. Till now I was just trying to flatten all four sides of mortise with a chisel. I'll experiment on that.

Is anybody using skew chisel to work on the walls of a mortise? It could in theory make it more like cutting rather then chipping the fibers.

[Patrick Chase]

Is anybody using skew chisel to work on the walls of a mortise? It could in theory make it more like cutting rather then chipping the fibers.

Properly executed paring cuts with conventional chisels cut rather than chip/chop as well. That's more or less the fundamental distinction between paring and chopping. Skew adds a "slicing" component and a lower effective cutting angle, which can sometimes be useful.

I've used skew chisels to pare through mortises. They worked well, but I'm not convinced that they allowed me to do anything I couldn't have done by paring with any other suitable chisel. Skew chisels are less useful with bottomed mortises, for obvious reasons.

Full disclosure: I'm a skew nut, so if anything I probably overestimate its usefulness. I have L+R sets of 30-deg skews at 1/2 and 3/4, as well as L+R 1/4 "dovetail skews" with ~11 deg skew angle to allow them to optimally work the corners of blind DTs.

[Trevor Goodwin]

I have found skew chisels useful for smoothing the ends of the mortise where you are dealing with end grain. In soft timbers like pine, it difficult to clean up the end of mortise without tearing the end grain, so a skew does a better job by slicing on the way down. A straight chisel that matches the mortise can't be skewed so you need to take very light cuts and a have a super sharp edge.

[Stewie Simpson]

If there has been a downside to the recently discussed topic on the glue strength between 2 mated surfaces, we are seeing it in spades on this post. We are not dealing with the requirements of a gluing 2 boards together along their side edge. Were talking about an interlocking mortise and tenon joint. There is an intrinsic mechanical advantage within an m & t joint, that cant be duplicated by glue alone. The choice between a rough or smooth surface has no practical legitimacy based on the facts that your having to work the chisel in a downward direction, into cross grain fibres, to remove the remaining waste to the mortise lines. Regardless of the inherent rough surface, the applied glue will work out just fine as your not dealing with end grain. If your still having major concerns on the integrity of the stopped mortise fit, you have some additional choices available during the planning stage. You can decide to further deepen the fit of the stopped mortise and tenon, or you can bypass the whole idea of a stopped mortise and tenon, and proceed with the benefits offered within a through mortise and tenon.