Hand planing after machine jointing?

You forgot one.

MikeL in SoCal

>7. A power jointer takes up a lot of shop space (which is a big deal for some of us).

Cheers,

Mike

There ya go...

Scott in Douglassville, PA

>I paid $90 for my jointer, from a neighbor who was liquidating his shop. Fast.

Re: Sprung joints

Scott Post

>Lots of books mention sprung joints, but that doesn't really mean anything. How could Moxon look at a 100 year old failed joint and say that it was or wasn't sprung? Charles Hayward (my favorite WW author) says to use sprung joints then in the very next paragraph explains rubbed joints which must be dead straight.

I can't help but wonder how much of this theory sprung (sorry!) from the desire to help students avoid convex edges which are really bad. Planes naturally want to create a convex edge so perhaps instructors pushed concave edges to counteract this tendency.

Personally, I shoot for a straight edge and if I get a slight concavity I don't worry about it. Convex edges get fixed.

Re: Hand planing after machine jointing?

Sanford Levy

>Jeff, a light pass with a sharp no. 7 makes a much nicer edge, even if you do not do a "sprung" joint. A magnifying glass over a joint finished with a hand plane will look a lot nicer, especially if the machine jointers knives are not brand new. Sanford

Re: Sprung joints

Pam Niedermayer - Austin, TX

>I think the old texts would have described accepted practice, don't think they would have been overly concerned about possible student/apprentice mistakes. After all, the student had seven years to learn how to do it properly. Today? Maybe a different story.

I disagree that planes want to create convex edges. They do want to plane along whatever surface presents itself, unless it's sufficiently convex to force a dig in.

I aim for rubbed edges on panels, probably because of the short edges; but I'm no expert. Even with sprung joints I'll rub a bit before clamping, just superstition probably.

Pam

Gotta remember to change subject line when needed!

William R. Duffield, on the Cohansey

>

Sprung joint beginnings theory

Russell Seaton

>I think the idea of using a sprung joing when edge gluing borads began when the only available wood was home made and air dried. By home made I mean the cabinet makers and joiners contracted with tree cutters to cut and slab wood and then the cabinet makers air dried the wood at their shops/barns/houses. They did not go to the boutique wood store and buy 20 board feet of whichever wood they needed for that project, as you can today.

They also did not have very dry and stable kiln dried wood at 6-8% moisture content to use. Kiln dried wood gets drier than air dried wood and will not reabsorb as much water if exposed to moisture. Kiln drying hardens the lignum between the cells and prevents the board from reabsorbing as much water. Unless you live in the dessert or Antartica, your normal humidity will not allow air dried wood to get that low. Especially not in wet southern England or the vast climate fluctuations in the North East USA.

So when an old time cabinet maker was edge gluing relatively wet boards together and using less modern finishes on the end grain which do not retard water as well (shellac and non boiled oils), he had to account for the further drying of the wood which would occur throgh the end grain and had to make a sprung joint. Modern woodworkers using dessert dry and more stabilized kiln dried wood don't have to account for their wood drying much more and don't have to use a sprung joint.

Kiln Dried vs. Air Dried Wood

Don Thompson, Cutler Ridge, South of Miami FL

>Are you stating that kiln-dried wood does not reach equilibrium with its environment in the same way as does any other wood? I thought that KD wood was a cheap way to get wood dried and out the door, not something that fundamentally changed the wood, for the better.

I can find no reference in my copy of Hoadley's Understanding Wood that KD wood does not have a similar Equilibrium Moisture Content to AD wood at a given Relative Humidity level and temperature.

I quote from Hoadley: "One of the more unfortunate yet common fallacies is that kiln-drying leaves wood irreversibly dry, and that once dried the wood somehow becomes dimensionally stable."

But, I am not an expert.

That's not my experience

Scott Post

>I've got both kiln and air dried woods in my shop. For several species I have both. Right now I've got ash, walnut, red oak, poplar, and soft maple in both kiln and air dried (along with a few other species of just air dried). I just did some random checks and within a species the moisture content is the same. I get a species to species difference (1-2%) that I chaulk up to the conversion tables that came with my meter. This tells me that there's no difference between kiln and air dried when it comes to stabilization with moisture changes.

Re: Kiln vs. Air Drying, EMC and Finishes

William R. Duffield, on the Cohansey

>R. Bruce Hoadley disagrees with you. In Understanding Wood, he states, "One of the most unfortunate yet common fallacies is that kin-drying leaves wood irreversibly dry, and that once dried the wood somehow becomes dimensionally stable. In reality, if dry wood is stored under relatively moist conditions, bound water will be readsorbed to the equilibrium moisture condition."

USDA Forest Products Lab also disagrees with you on many points. Note - selecting the following link will download a large .pdf file that is over 2 Mbytes. FPL-GTR-113 Chapter 15, Finishing of Wood is worth downloading and reading.

Table 15-3 of this publication shows that shellac is marginally more effective than either polyurethane varnish or spar varnish in inhibiting moisture transport. Two-part poly (catalyzed varnish) is somewhat more effective, but it is rarely used in home shops or in the vast majority of small commercial shops.

I don't think there is any evidence that boiling or adding metalic driers affects the final polymerization of fully cured drying oils. It just increases the speed of polymerization. The table referenced above makes no distinction between raw and boiled

Some people still prefer air dried wood. Some people still prefer shellac, for good reason.

Kiln vs airdried wood

Bob Hackett

>I`ve heard similar arguements from alot of supposedly knowledgable WWers.The only real world changes that I`ve seen between kiln dried and airdried wood is that kilns change the color and workability of wood,and most times it`s not for the better IMO.The exception to this would be using a kiln to dry softwood and then stabilize the pitch at a higher temp,something which does not take place when airdrying.

It`s my understanding that the only thing that stands between any wood and moisture is the finish on it.The finish only prolongs the time it takes for the wood to meet the EMC.The EMC will be the same for either kiln or AD.

My experience also tells me that "setting the lignin" by kiln drying also makes the wood more brittle and prone to tearout.KD is also more prone to failure during steam bending.

Ask any experienced turner what he prefers and he`ll tell you AD.The color is more vibrant,it cuts cleaner,finishes better,and generally doesn`t act like it`s had all the life beaten out of it.For both turning and general WW,I far prefer AD.But then again,I also cut and mill most of my own lumber from tree to finished product.

I`d go so far as to say if you can`t successfully work with AD wood,then you really don`t understand wood as well as you should.AD opens doors other than those the lumberyards and wood merchants make available to you.I`d suggest you take another look at Hoadley`s books and stop selling yourself short.

Mainely,Bob

What he said!

Don Thompson, Cutler Ridge, South of Miami FL

>Bob,

I did not mention what you had to say about KD wood because I could not support it by reference or experience, but Kelly Mehler, in his lecture this weekend (he has a rep for making solid wood furniture) started out by telling us not to use KD wood for fine furniture. He mentioned the tearout problem, and others. He said that it can "case dry" and then when you resaw it, you get to bananas.

I have no comparitive experience with this, but I will be alert to it in the future, when possible.

Moxon

Adam Cherubini, NJ

>Pam,

No mention of sprung joints in my reading of Moxon. First page talks about just such a joint being "so exactly straight , that when set upon one another, light shall not be discern'd betwixt them."

Some may interpret this as a clear example of the opposite point of view: In this case, some indightment of those who add stuff to traditional woodworking for some purpose or simply mistakenly.

My take is that Moxon missed things. He wasn't a woodworker or tradesman of any kind. He was only an observer and as such should be respected for his detailed observations. But he confuses the distinction between try and jointer planes and contradicts himself in other areas. This is such a fine point, one can't blame Moxon for missing it, if it were a common practice.

Adam

Russ. I buy it!

Adam Cherubini, NJ

>Russell writes:

I think the idea of using a sprung joint when edge gluing boards began when the only available wood was home made and air dried.

I buy it. I think you are right on. A couple other points that shouldn't be left out:

1) Hand planes DO cause snipe like power planers. If anything, good technique is important to stop edges from going convex (especially the far edge)! The concave edge is easier to produce and the typical starting place for every straightening attempt. (This is the way to straighten a board without a straight edged ruler, for example).

2) The sprung/convex match joint needs only a single clamp. Using hide glue, this single clamp/spring joint combo allows better bondline thickness control (which is important for hide glue).

By home made I mean the cabinet makers and joiners contracted with tree cutters to cut and slab wood and then the cabinet makers air dried the wood at their shops/barns/houses. They did not go to the boutique wood store and buy 20 board feet of whichever wood they needed for that project, as you can today.

I get your meaning although this probably isn't literally true. Here's a sample, admittedly out of context:

�0-2-9 on 4/5/26 "33 foot of Goom [gumwood] Bord,

That's 1726. I read 33 foot as 33 board feet (I hav my reasons) and the price is about 40% more than the going rate. Sounds like a boutique to me, but Gum? They must have seen him coming!

As for "slab wood", I suspect the lumber industry sawed 4/4 material when consumers demanded it. I've seen no evidence of cabinetmakers or joiners resawing their own stock. Some owned their own saw mills and I regard that as different.

Kiln drying hardens the lignum between the cells...

I agree. Some mills seem to do this better than others. I have KD boards that have a thin hardened outer layer like you describe. Almost like case hardening. Suffice it to say, I don't buy their lumber anymore.

Adam

Re: Moxon

Pam Niedermayer - Austin, TX

>Thanks, Adam. Does anyone else mention sprung joints? I haven't read any of these old texts.

Pam

Re: Moxon

Adam Cherubini, NJ

>Pam,

Keep in mind, there are no 18th century wood working texts in the English Language. Moxon's was written in the 1680's. Nicholson's "The Carpenter's New Guide..." was published (repeatedly throughout the 19th c) perhaps first in 1811 or so. It may have been written before the end of the 18th so this could be the only one true 18th c text. I don't have a copy so I can't say for sure about it.

George Ellis' "Modern Practical Joinery" written in the beginning of the 20th c, talks about springing joints, as does Bernard Jones "The Complete Woodworker", written around the same time.

I have a few other texts from the industrial revolution. I would expect them all to discuss spring joints, although their methods and justifications are often funny. I get the sense that they know its the right thing to do (because it has been passed down for a centuries) but they really don't know why and their techniques may be wrong.

There's little question (not none, little) in my mind that spring joints were standard procedure in period workshops. As I stated elsewhere, they are easier to produce, require fewer clamps, provide better bondline control, etc. Its certainly not something made up in a 1975 FWW article. There just is no 18th c smoking gun.

Adam

Nicholson's "The Carpenter's New Guide

Don Thompson, Cutler Ridge, South of Miami FL

>I spotted an 1801 3rd edition for sale ($450), so I guess that the first might have been in the 1700's.

Sounds like a fascinating book.

Industrial revolution

Pam Niedermayer - Austin, TX

>Thanks, Adam. Sprung joints made sense to me on first exposure, an instant "aha" experience, for what it's worth. Not that I knew all the reasons why they're good; but I do tend to trust my intuition on mechanical issues.

Pam

Re: Hand planing after machine jointing?

R.J.Whelan

>Concur ....

Per Marc Adams

Russell Seaton

>I attended a class by Marc Adams recently. Per him, kiln drying wood hardens the lignum in the wood. Lignum is the "glue" that holds the cells together. This hardening of the lignum prevents the kiln dried wood from ever becoming as wet as it could be. The wood is chemically changed. With air dried wood the lignum is not hardened from the chemical process of being "cooked" in the kiln. Thus it can achieve a higher moisture content if you soaked it again.

To sort of prove this to yourself try carving air dried and kiln dried oak. Which carves easier? Have you ever wondered how or why the European carvers would have used such uncarveable wood as oak in many of their church carvings? Wouldn't they have used a better carving wood? Or is it because air dried oak isn't nearly as awful to carve as kiln dried oak?

Have you ever tried steam bending wood? Have you had much luck with kiln dried wood? Or better luck with air dried wood? Is this because the actual structure of the wood has been changed during the kiln drying?

How low?

Russell Seaton

>Are both your air dried and kiln dried wood at 6% moisture content? 5%? Or is your moisture meter only measuring about 10-12%? I am talking about the absolute minimum moisture content. Kiln drying can get you to a lower minimum than air dried. 8 to 10% is a fine moisture content for working the wood. Both air and kiln dried will do this. You don't need or really want much lower than 8%. But kiln drying can get you lower.

Re: Per Marc Adams

John in NY

>My experience too is that the wood is different after kiln drying compared to air drying and I would never try to steam or soak bend wood that has been kiln dried.

Re: Russ. I buy it!

Russell Seaton

>Glad to have some support. Every other responder failed to argue with my main point of why spring joints were developed. They argued against the irrelevant points and did not address the spring joint position.

I bet centuries ago woodworkers were in business to make a living. And they made do with what ever they had. And they did not have an easily obtained supply of dry ready to work wood. They had plenty of wood of varying workability.

And they probalby did not have the luxury of telling the customer that they would build the piece of furniture when the wood was as dry as they liked. They probably said I'll have it when you want it. And they probably found some wood, maybe not ideal, but usable. And put spring joints into the edges because they knew the wood was going to dry a lot more after the furniture was built.

They devised work arounds to get the job done with what was available. Spring joints were one of the useful work arounds. But that does not mean it is appropriate or useful today when the work around is no longer needed because our wood is much drier when we begin working it.

Re: How low?

Scott Post

>How low the wood is taken in the kiln is irrelevant to the moisture content when you work it. Unless you're in Arizona the wood will start to come up in moisture content the second you take it out of the kiln. Wood dried to 6% will be at 9% within a week of entering my shop this time of year. Wood air dried to 12% will likewise be down to 9% within a week in my shop. In fact, it was about a month ago that I brought a load of ash and poplar home and posted the results on this forum - the boards on the top of the piles had acclimated within 3 days. If I remember right, the ash was kiln dried and I know the poplar was air dried.

Both the kiln and air dried lumber in my shop right now are at about 9%. In the summer I run a dehumidifier but the wood will still come up to 11% or more because of ambient humidity. This isn't from a book or an instructor - these are actual measurements I've taken. I usually measure wood when I bring it into the shop and before I use it so I have a good feel for where it stabilizes at various times of the year. Kiln drying has nothing to do with stabilization.

I'm not sure what Marc Adams was trying to tell you regarding MC in kiln dried wood (he's a smart guy and great instructor) but I think you misheard him. His shop is about an hour south of mine so I know he and I will see the same seasonal changes in the wood in our shop.

On the issue of workability of air vs. kiln dried, I've never noticed a difference in hardness or propensity to tearout. That doesn't mean it isn't true - just that I haven't noticed it. I've have both air and kiln dried ash that'll be going into my next project so I'll see if I can tell. I will say that I vastly prefer air dried wood from an initial stability standpoint. In my area the majority of kiln operators are too focused on speed and induce stresses. Trying to resaw 4/4 lumber into 1/4" bookmatched panels from these guys is an exercise in frustration - the wood warps like crazy. It's also easy to tell air from kiln dried walnut. Air dried has beautiful colors while kiln dried is a uniform brown.

Re: How low?

Scott Post

>Russel - I just went back and re-read what you wrote and I think I misread your position. It looks like we agree that kiln and air dried wood will acclimate to the same level.