Jointing 12 ft boards for a tabletop?

[wdwerker]

I have some heart pine planks for a tabletop. 12 ft is way too long for my 6" joiner. I have had good luck with a router and an 8 ft straight edge for big tops before but a 12 ft one piece straight edge seems hard to find .

Any approach you have used for clean tight long edge to edge glue joints?

Planks are quite straight already, they were resawn from a salvaged beam.

[Boatworks Today]

For long planks like that I've always had good luck using a jointing hand plane and winding sticks. Typically I'll snap a parallel line down both faces to help provide a visual reference then switch to the sticks when I get close. This can get a little tricky with thinner stock (4/4) but I'm guessing you're using 6/4 or better?

[Vic]

I would sandwich them together. Keep the top or the bottom facing each other, so that if you fold out from those edges, it would be the joint line. Then just use a No. 7 or No. 8 handplane and joint. Any inconsistency in bevel will be a match. Also, it'd be a good idea to slightly spring joint the edges, so pressure applied to the middle really pulls the entire edges together.

[Beechwood Chip]

Back before people could order straight edges over the web, people used to make their own. You take two pretty straight pieces, rub them together, and remove any places where they touch (high points). This will make two pieces that fit together perfectly, but they may have curves that fit together. So, you take a third piece and repeat the process with all three pairs. When done, all three will be dead straight. If you just want a glue joint and don't care if it's perfectly straight, you can stop after each pair matches.

Stone masons did this by sprinkling abrasive between the pieces and rubbing them. I was thinking you could take some sand paper, fold it over so it was rough on both sides, and put it between the boards. But you'd need 12 feet of sandpaper. It might be better to use abrasive sand.

I'm picturing a frame to hold two boards edge to edge, with one on top of the other. Sprinkle some abrasive on the bottom one, and then slide the top one back and forth.

Hey, once you've got the first three edges dead straight, you have your 12' straight edge to use with your router.

[duckkisser]

if you need a long strait edge just get a metal hollow stud or some other kind of strait edge from perhaps roofing or some other kind of construction material and use that as a strati edge.

[wdwerker]

I priced a 2" x 4" aluminum rectangular extrusion. It comes in a 24ft stick for $436

[rmac]

Here's an idea that might work and might cost less than $436.

1. Get some relatively thin monofilament fishing line. Stretch a piece tightly from one end of the board to the other. Position it back from the edge two or three inches as though you were going to use it to guide your router. It will be as straight as anything in your shop.

2. Carefully place three pencil marks on the board immediately adjacent to the string ... one on each end and one in the middle.

3. Remove the string

4. Line up your eight-foot straight edge with the middle mark and one of the end marks, then use it to guide the router to joint half the board.

5. Repeat step 4 for the other half of the board.

6. Relax with a root beer.

-- Russ

[wdwerker]

After several delays by the client we routed the 12 ft planks for the tabletop yesterday . Before I went to the effort to shift the 8 ft metal straight edge I tried using a 12 ft scrap of countertop with a laminated edge. Worked like a charm!

The frame around the tabletop is old heart pine. We used double faced tape,really thin kind (not fabric),to hold the 2x4 to the straight edge .

I still plan on making a straight edge guided base for my router. Getting the tape adhesive off the bottom of the boards was no fun. Had to use a cabinet scraper and keep pulling all the sticky blobs away.

[Guillaume Breton]

do you have any pictures of that setup i'd be interested to see. i have trouble imagining everything ! ty

[wdwerker]

Sorry this site won't let me post pictures from my iPad. I had a scrap of 1 1/8 thick particle board which is used for commercial countertops, desktops, stuff like that. One long edge had laminate on it, you know like Formica....

Clamped a 1" by 11" piece of heart pine to it, ran a router bit with a bearing on the bottom down the length of it and got a straight enough edge to glue up. We cut domino slots down the edge to help keep the boards surfaces aligned during glue up and it came out pretty nice.

We cut the breadboard ends today and sanded the top . Top came out 39" wide. Hope to get the frame built in the few days we have next week . 6 x 6 rough sawn legs in heart pine are pretty heavy .