Edge gluing

[richard b miller]

i tried my first edge glue using 15" long poplar. i'm not overly impressed. i can see the seam.
when you edge glue, should it look perfect? or am i just being a perfectionist?

thanks

[mark mcfarlane]

Do you mean 'applied edge banding to Poplar'?

[Al Launier]

If Mark has assumed correctly that you are edge banding, then my comment doesn't apply. On the other hand, if you are gluing boards together along their edges to make a "panel" of some sort, then I would ask if you are using a caul(s) to against the faces of the boards to align the faces to the same plane. The caul clamping would be in addition to clamping the edges together.

[lowell holmes]

If the faces are perfectly smooth you can glue them together by applying glue to both faces and rubbing the faces together.
This known as a rub fit. I plane the surfaces prior to applying the glue. No clamping is required.
I've never tried this with edge banding.

If joining two boards it helps to make the lengths of the joint very slightly concave so that when you apply the clamps, the surfaces will
spring together and hold tension on the joint. We are only talking about a couple of passes with a hand plane leaving translucent shavings.

[Brian Tymchak]

Depending upon how well you matched grain, the joint should be slightly noticeable. You should not see any obvious evidence of glue though. Could you post a picture of your glue up with a close up on the joint?

[David Eisenhauer]

Short answer, pretty much should be 99.99% not visible, given that the grain matches (sometimes a big given). Longer answer is that the edges to be glued need to be "joined" (or trued to match the opposite side) until the "line" disappears and there are a couple-three ways (table saw/good blade combo, power joiner, hand plane, etc) to accomplish that. In the real world, this is achievable fairly often, again given that the grain lines and/or surface coloring match.

[Prashun Patel]

Please provide more information. Best: a picture.

The seam will be near invisible after glue up if:

The boards must be jointed well.
The mating edges are perfectly square (or at least 'supplementary'; when you clamp, the faces should be coplanar).
The grain match is good.
There is even clamping pressure along the entirety of the joint.

The seam will be near invisible after a long time if:

You are lucky.

[Robert Engel]

It depends on why you are seeing the seam.

Is it because the two edges weren't jointed well or because of clashing grain patterns? The jointing is easily perfected with practice the grain matching is a visual thing. Jointing two lengths of wood from the same board or same tree helps a lot.

If its neither of the above, then yes you are being a perfectionist.

[Myk Rian]

I really doubt this is an edge banding. He said edge gluing.
I did a demo on this for our WWing group last month.
You WILL see the seam. After the glue dries, run it through a planer or sander.

[John Lankers]

Poplar is a relatively soft wood with subtle grain lines and should close tightly after proper jointing without leaving a visible seam.
Shorter boards like the ones you were working with can be clamped together in a bench vise with the edges to be glued facing up and hand planed. This produces two matching surfaces when put together - boy, this is harder to describe in words than actually doing it.

[richard b miller]

guys-
no, i'm not edge banding. i'm edge glueing.
346846

[Brad Shipton]

Look at any typical solid wood cabinet door and you should be able to replicate the joints you will see in the panels. I would look at your machining steps and equipment setup. There are a number of possible causes for the joint you have shown.

[richard b miller]

i took a piece of 8/4 poplar and resawed it in half, ran it thru my planer and tablesaw to smooth all edges. i have a $$$$ maples blade.
as you can see by the pic, i have a gap. i didn't use cauls along the body but did used them on both edges

[Chris Padilla]

How did you handle the edges that you are gluing? Hand plane? Rip on the table saw? Joint on a jointer?

[John Lankers]

Richard, to me it looks like you're facing several issues:
1. After resawing a board leave it alone for at least 24 hours (some wood species need a lot longer) so that the tension in the board
can release. In my experience resawn lumber is much more prone to warp, cup, twist or what ever you want to call it than lumber
that was left "intact".
2. Joint one face flat, the planer can not flatten a board it will only make both sides parallel to each other (banana in banana out).
3. Edge jointing can be done on the table saw but the blade must be 100% perpendicular to the table and uneven feedrate or pressure against the rip fence can introduce inaccuracy. Small boards like this can easily be jointed with a hand plane.
4. Always check with an accurate square and don't rely on machine setup only.
5. Before gluing the boards hold the edges together and see if there are any gaps, if yes joint the edges again. The strength of a glued up panel relies on a tight fitting joint, wood glue is not a gap filler. Don't rely on brute force to close any gaps, they will probably reappear or cause the panel to crack elsewhere eventually.
6. Clamping cauls over and under the board help keeping the panel flat when applying clamping pressure to the edges.

You can glue up a face and edge jointed panel and plane it to final thickness after the glue up, just try to remove equal amounts of wood from both faces.

[lowell holmes]

You can repair a glue joint by ripping down the center of the joint on a good table saw with good blade in it, leaving two edges that are flt and square to each other. Then without further ado, glue them back together again. I would use clamping cauls as previously suggested. The blade should be a Forrest or equal quality.

[Jerry Miner]

5. Before gluing the boards hold the edges together and see if there are any gaps, if yes joint the edges again. The strength of a glued up panel relies on a tight fitting joint, wood glue is not a gap filler.


^^^ This!

Great advice, John

[Erik Christensen]

while it is 'possible' according to generally accepted lore to have a 'glue ready' joint straight from the TS I have not been able to do that and I have a euro TS with 10" ridge carbide rip blade (also tried same with freud 'glue line rip')

the only way I have been able to get a perfect glue edge - defined as perfect flat & straight edge face and 2 defect free 90 degree edges - is with a jointer - either hand or powered

[richard b miller]

confucius say man who has blade tilt is off just a little bit!

from all the stuff i read, i checked my blade tilt. first off, to check tolerances, you have to have ACCURATE gauges. found my igage digital angle gauge doesn't measure accurately.
i used my drafting triangle to set the blade perpendicular to the table. when the blade was perpendicular, the digital gauge read 88.5.

i'll redo the edge gluing over the weekend and let ya'll know how it turns out.

i really want to thank all who had an input. this forum is a real lifeline! thank you.

[Tony Leonard]

Don't forget the old fashioned check too...make a cut, then flip one side and check the joint against a flat surface (like your TS). The gap is twice the "error." I'll be honest, it is rare that I depend on the TS to make edge joints. I usually run it over the jointer and sometimes touch it up with planes. The other thing you could try is flipping the faces - ie. cut one face up and one down. That sometimes works. There is a lot of good info out there on edge joining. Lots of variables here! The trick is to minimize them best you can. No such thing as perfect! Good luck with it!

Tony

[richard b miller]

SUCCESS!
tweaking my table saw did the trick!!
my fence was 0.030 off at the far end (past the blade) and was also tilted slightly. i adjusted it
to <= 0.010 and perpendicularly, i used my drafting triangle and couldn't get a 0.004 feeler gage between it!

thank you all for your input! it was greatly appreciated :)