Edge Jointing Heresy!

[BradNaylor]

I've been glueing up a desk top from three boards of 1 1/2" oak this afternoon, and as is my normal procedure I assembled them straight off the table saw with Dominos for alignment - I never bother planing the edges.

As always, the joins were perfect and from rough sawn boards to clamped up panel took no more than 45 minutes. It got me thinking, though.

Every text book I've ever read goes into great detail about planing the edges of boards before glueing them up, whether with a hand plane or on a jointer (planer).

Why?

I've always found it totally unneccessary, so long as the saw blade is sharp and you get a straight cut.

I appreciate that some people like to have slightly concave edges, the idea being that the ends are less likely to seperate due to shrinkage, but plenty of text books recommend completely straight edges. Surely this is more accurately achieved straight off the saw.

I've discussed this with my mate Phil who considers me a complete heretic. Nowt wrong with my joints, though!

So can anyone give me a good reason why I should plane the edges of my boards before glueing them together?

Cheers
Brad

 

[Mr Ed]

I suspect it depends greatly on the quality and accuracy of the saw you cut the boards on. I know that on my small Kity saw the edges will be broadly straight, but far from suitable for edge gluing. I don't really mind that as a couple of runs with a plane takes a matter of minutes.

I have no doubt that with a quality saw and the right blade that gluing straight off the saw is a practical reality.

Cheers, Ed

 

[xy mosian]

Hi Brad

I agree. I have found similar results when straightening edges with the router. My table saw is very rudimentary as I do not often need one. However if relying on a 'rubbed joint', rather than biscuits, dominos or loose tongue with clamping, it is not quite so easy to achieve the 'rubbing' action with two machined surfaces. I have successfully edge jointed boards using a rubbed joint technique and no across the joint clamping at all.

xy

 

[Doctor]

Burn him; he's a witch.

 

[SBJ]

We dont like your sort round 'ere. Where's my pitchfork?

 

[Ross K]

"So can anyone give me a good reason why I should plane the edges of my boards before glueing them together?"

Is this what is known as a "troll" posting? If you have such consistent success with edge jointing straight off the saw then why ask the question?

I would say carry on doing what you're doing if you believe it works for you.

Personally I'll not go down your time-saving method but will continue to finish all my edges on a surface planer, alternating the direction of planing on each edge to cancel out any minute errors in squareness of the planer fence. If you want your customers to not come back with table tops falling apart I'd recommend this method.

 

[woodbloke]

DanBrad :lol: - see my witterings here on machine accuracy. Ed's right though, the small K419 is simply not accurate enough to joint boards straight from the c/s. I'd usually skim them on the p/t and then run a try plane over them to make them concave (fag paper thickness in the middle) before gluing, no Domino's though Swiss biscuits only - Rob

 

[Doctor]

I'd like to see you do this one off the saw

 

[mailee]

My saw is good but not that good. Even with a new blade in it I still have to run the edges over a jointer or router and straight edge before jointing them. Sounds like your saw is a great time saver Brad. If my saw was as good I would do the same saving time. :wink:

 

[Sgian Dubh]

So can anyone give me a good reason why I should plane the edges of my boards before glueing them together?
Cheers
Brad

I can give you some reasons in a discussion I wrote on the subject here, http://www.richardjonesfurniture.com/Ar ... inery_Text but I suspect you'll remain unconvinced, ha, ha.

In contrast to your experience I can say that over the last 35 years in the business I have seen many failed joints in panels joined just as you describe, and a much smaller percentage of failures in panels joined with a well prepared and assembled sprung joint. My experience is of course only anecdotal for I have never systematically collected and analysed data to determine the failure rate of one method of joinery over another.

Still, as long as you never experience failure using your method I'd say carry on as you are; but if you start to experience failure on a fairly regular basis it might be time to look at and analyse the cause and to perhaps change your methodolgy. Slainte.

 

[brianhabby]

I've wondered about this myself. Also being a 'Norm Student' so to speak, he always insists on planing or jointing the edges of boards before glueing.

However, I'm sure I've seen someone on the box say that a sawn edge is actually better than a planed edge because the slightly rougher finish gives the glue more grip. I think it was Rico Daniels (Salvager) but don't quote me.

As others have said though Brad, if it's working then carry on with what you're doing

regards

Brian

 

[Doctor]

However, I'm sure I've seen someone on the box say that a sawn edge is actually better than a planed edge because the slightly rougher finish gives the glue more grip.

This is a myth, modern glues work better on smooth edges.

 

[Night Train]

If the sawn edge is absolutely spot on then gluing it as is would be fine for basic joinery work.

For fine work a planed edge gives a better and stronger glue join because that is the way modern glues work. Also there is significantly less chance of a glue line being visible if the edges are planed flat.

A rough surface will allow glue pockets to remain that that not only weakens the joint but can show through when finishing the surface.

 

[RogerS]

Slight digression but apposite, I think.

What gives greater holding power?

1) A nail driven into timber

2) A nail driven into a drilled slightly undersized hole?

 

[BradNaylor]

Personally I'll not go down your time-saving method but will continue to finish all my edges on a surface planer, alternating the direction of planing on each edge to cancel out any minute errors in squareness of the planer fence.

That's the thing.

The edge I get off my table saw is every bit as good as I can get on my planer. Look closely at the edge produced by any planer and there are slight ripples caused by the blades, not to mention the possibility of snipe on even the best set up machine. Edge jointing long heavy boards on a planer is always a somewhat awkward procedure, leading to the likelyhood of slight imperfections.

A hand plane will produce a smoother finish, but even the most skilled craftsman cannot guarantee a perfectly square and straight edge

A good quality table saw with a sharp finely toothed blade however, produces a surface as true as the planer but with more consistancy and accuracy.

I take the point about lower end machines but any properly set up industrial quality cast iron TS with a decent blade on it will give a surface suitable for edge jointing IMO

I've certainly never had one fail.


Incidentally Doc, how DID you joint the edges of those railway sleepers?

Cheers
Brad

 

[SBJ]

Theres a full description here.

I think it looks great, amazing what you can pick up at B&Q these days.[/url]

 

[9fingers]

Theres a full description here.

I think it looks great, amazing what you can pick up at B&Q these days.[/url]

Has this turned into a competition to find the link between Stu's response and the rest of the thread?

I know you were going to have to work the weekend but maybe you have been overdoing it?

Lol

Bob

 

[dennis]

You probably use the grain effect try to hide the joint.

Dennis

 

[FogggyTown]

I've wondered about this myself. Also being a 'Norm Student' so to speak, he always insists on planing or jointing the edges of boards before glueing.

However, I'm sure I've seen someone on the box say that a sawn edge is actually better than a planed edge because the slightly rougher finish gives the glue more grip. I think it was Rico Daniels (Salvager) but don't quote me.

Ah, Rico. The ultimate authority on fine woodcraft.

 

[Mr T]

Hi

What make and model of saw do you have Mr Naylor, I could do with one of those!

Chris