Ripping a Glue Line on Site

Have to glue boards edge to edge on the job site? Here are a couple of tips on preparing the edges for a satisfactory match.January 23, 2014

Question (WOODWEB Member) :
I need to edge glue a tabletop on the job site. The boards are 1 -1/2" yellow pine. The tabletop needs to be a little over 12' long. The boards have acclimated for two months. I have a portable planer on site.How can I straighten these boards for gluing? I'm thinking a straight edge and either a circular saw or a router. Keep in mind this table can be rustic looking.

Forum Responses
(Cabinet and Millwork Installation Forum)
From contributor T:
Use a Festo first, then power plane and edge if desired.

From contributor M:
A bench top jointer would do the job. Or you could invest on a Festool plunge cut saw.

From Contributor N:
Why can't you take the lumber to a shop that has the equipment to do the job right?

From contributor K:
To the original questioner: Get yourself a jointer hand plane, some winding sticks, and a couple of days (weeks), if you've never done it before. No matter what the pitch is, rustic only means sloppy until you get a call-back.

From contributor K:
To the original questioner: I saw your other post, and it looks like you're on that call back - bummer. There is no insult intended here, but perhaps it's time to look honestly at your capacity. Building a tabletop that doesn't crack to pieces is pretty basic furniture making skills. Finding the least expensive responsible way out should be your focus now. Learn to build tables later.

From Contributor I:
I agree with Contributor O that you should bring the stock to a shop with the proper equipment to prepare and glue up the top.

From contributor F:
Nobody's trying to beat you up but one has to conclude that you are in over your head. First 6/4 construction grade pine bought at Home Depot was kiln dried way too fast to avoid face checking (elementary), and second the MC is still way too high to use in furniture construction without splitting. The way out is to build your tops like a deck and leave a gap of 3/16 between each board and call them picnic tables.

From Contributor C:
I would say use a cleat underneath the ends. Bevel the ends so legs donít get banged and so that they are less noticeable. If the table is going to be rustic this should not be a problem. Use either one screw in the center or a slot to allow for expansion and contraction. This way there is no need for glue - just leave a 3/16" gap like Contributor F suggests. Donít forget to drill a pilot hole for the screws as pine can split. If you have to finish them do so on both sides and before you add the cleats.

From contributor B:
Use a straight edge to guide a router and put the two boards to be joined 3/8" apart. Then run a 1/2" bit down the middle. Any variation will be mirrored in the opposite board and if done correctly you will get a perfect joint. Be aware of rotation so the bit does not try and run down the joint.

From contributor F:
Don't glue boards together, space them 3/16" apart and use breadboard ends and cleats underneath every two-three feet. Look up harvest tables.

From contributor Y:
A straight edge and circle saw or router won't work unless the flat side of the boards is truly flat all in one plane. I doubt that it is. You will be referencing from a crooked surface expecting to get a straight cut. Did you order in kiln dried pine at 11% or did you get construction lumber from Home Depot? Even if it has lain around for two months it won't be stable and will likely crack. Biscuits won't add any strength to an edge to edge joint, might help you align during glue up. I don't want to sound too critical of your skill level but you need to learn more about furniture making and wood working before you get a really bum reputation and can't get these jobs in the future. Wood moves with changes in moisture, always! Learn how to accommodate it.

From Contributor J:
I just did a bunch of this and I purchased the Festool plunge saw with an extension rail to rip 12' material. Circumstances forced me to make some field glue up's and I discovered this setup beats any shop rig I know. Lay out the two pieces as they will be joined edge to edge. Flip one over on to the other face to face with the uneven edges as close to even and flush as possible. Then set up the rail on this stack, and rip both of these edges together at once just enough to clean them both off. Once cut, flip the top piece back over. The glue line is amazingly clean and straight, and ready to glue and clamp.

From the original questioner:
To contributor J: Your advice is some of the most helpful so far. I have a Festool saw and guide but opted for a straight edge made from two strips of 1/4" MDF and router and a straight bit. This method and yours will only work if the surfaces of the boards are planed first. Anyway, the job is completed the client is very happy and my reputation is intact.

From Contributor J:
Thanks. I should have mentioned that the wood was western red cedar, smooth on back and rough faced. Anyone that has used this stuff knows it is very uneven, yet the method worked.