Machine cut joints....imporantance of cleaning up with hand tools??

[George Farra]

Good Morning All,

I watch a couple of woodworking shows and like anything in life there are always differences in how things get done. Tommy McDonald emphasizes that machine cut joints need to be cleaned up with hand tools yet other show hosts do not.

So, is this one of those things where if the joint will be seen clean it up where it wont don't bother?? I can see the benefit of cleaning up a half lap, which will be seen, but not a mortise and tenon if the joint fits snug off the machines.

Thoughts??

Thanks

George

[Mel Fulks]

I can only guess he wants the joints to look entirely hand cut. I don't think its a good idea.

[Gerry Grzadzinski]

If I'm cutting joints with a machine, they're ready to go right off of the machine. What exactly needs "cleaning" up"?

[Stan Calow]

If you're talking specifically about M/T joints, I guess I have never made one that did not need tweaking with hand tools. Standard advice I've seen is always cut the tenons oversize and tweak to fit the mortise. But I also have never gotten a nice clean mortise (like you see on TV) using a hollow-chisel mortiser. They've always needed to be cleaned up by hand chiseling. The TV programs edit out a lot of the uninteresting details.

If you're talking about joints in general, I think power tools get you most of the way there, but the hand work finishes the job. The better your technique with machines, the closer you get to not needing hand tools.

[glenn bradley]

There are some machine cuts that leave a less than ideal surface. When cutting a rabbet with the tablesaw as two perpendicular cuts as opposed to using a dado stack I will sometimes leave a little ridge in the rabbet that I clean up with a shoulder plane for example. The fact that I can quickly clean it up with a shoulder plan may actually make me a little casual now and then. Unlike epoxies, PVA glues work best on smooth mating surfaces. That being said, I'll echo what Stan says in that proper machine setup and careful execution will generally leave surfaces well 'within spec' for gluing (IMHO). I do not build with any 'show' surfaces coming right off the machine but, joinery is a different matter. Different strokes . . .

[Jim Becker]

There is always a need to remove machining marks from wood components...saw blade scratches, planer/jointer knife marks, etc. How you do it is up to you. In some cases, using properly sharpened hand tools appropriate for the given job can provide a superior surface as compared to sanding, but subsequent finishing steps many or many not call out the benefit depending on choices that are made.

And since there is a learning curve to using hand tools (including the proper sharpening piece), unless one has the time to invest in that extra work, sanding may be the better choice at a given moment.

Relative to M&T, refining the fit with hand tools is a given...but while a snug fit is important, there's an advantage to an "imperfect surface" in the joint relative to glue-up. IMHO. Modern glues (PVA and it's variants) penetrate the wood for a strong joint once cured so a super slick surface might not be best for that initial penetration, especially on certain species of wood. What you actually want is "perfect shoulders" and what's inside is less critical if it fits properly.

[Alan Bienlein]

I only ever use a hand tool on a joint only if it needs some tweeking to fit otherwise it goes straight to glue up. The only exception is hot hide glue joints. We always make sure to have a smooth plane cut surface as the hide glue likes it much better.

[Frederick Skelly]

I find that my machine made dados fit better when I use a router plane to make sure I have a consistent depth. I tried a machine made mortise this morning and see some value in trimming up the very bottom of the mortise with a chisel. Works for me, anyway.
Fred

[George Farra]

thanks everyone. For me i seem to mess things up when I bring a hand tool to the party, but that is primarily due to a learning curve. I get the whole need to use hand tools to tweak parts to fit correctly. what confused me was the need for smooth mating surfaces on joints that would never been seen like a M/T joint. I cut my tongues oversized and fit the part, but I have never worried about the mortise walls.

I guess I never considered a shoulder plane to clean up a rabbet since I use a router rather than the TS. All good stuff here. Thanks for taking the time to reply

Regards

George

[Lee Schierer]

Back before I got my tenon cutting jig, I would nibble or use a dado blade to make the face cuts on half lap joints to remove the saw marks. Most dado sets cut slightly deeper with the two blades than the chippers do so some clean up would appear to be needed. With the tenon jig I make a single face cut then remove the rest of the material with the tenon jig and a ripping blade. This leaves a perfect glue surface. Router cut dadoes are usually good to go right after machining. Machine cut dovetails require little if any clean up if your set up is right.

[pat warner]

Router cut? Then don't re-tool those surfaces.
If your fixturing is on the money, and it should be (or why bother?),
then leave the work alone.
Good cutters with solid fixturing yield the best of joinery.

[Brian Tymchak]

I would think that from a "strength-of-joint" perspective, the higher amount of mating surface in an M&T joint the stronger it will be when glued. If the walls of the mortise or the faces of the tenon are milled haphazardly, that would lead to less mating surface and a weaker joint, IMO.

[George Farra]

thanks everyone. regards, george

[Robert Engel]

I've found the time it takes fiddling around to get an exact cut right off the machine is better spent fine tuning the joint with hand tools.

I can do them faster and much more accurately.

That's how I do it, others go strictly with machines.

Find what works for you. A lot of guys don't want to have several hundred $$ invested in hand planes.

But I find them worth their weight in gold!

It depends on your philosophy about ww'ing.

I decided a few years ago I wanted to be a craftsman, not a "wood machinist".

[Mel Fulks]

Robert, good points. I'm used to using machines to often make stuff in quantity ,with plenty of scrap to get machines exactly right. When using machines to make single pieces of furniture it might well be good policy to fine tune by hand instead of using inordinate time and material to adjust machine.