How to get straight board edges

[Michael Furey]

I'm building a table top out of 8/4 cherry and the boards are 9' long. I don't have a table saw (even if it did, it'd be a bench top one and that probably wouldn't work too well), I have a 6" bench top jointer, but that's way too small for these boards. What's the best way to get a perfectly straight edge on these boards so I can glue them up and not have any gaps? Normally I use pine that's S4S and any gaps I can clamp shut, but this wood is only S2S. I have the Kreg rip cut jig that I used on my circular and that helped get the edges pretty straight, but not good enough. I've been using my hand held power planer, but that's tough too. I was thinking of either using a straight cut router bit with a guide bearing on the end (if I go that route, what would I use for the bearing to follow to make it straight?), or I was thinking of getting a track saw. I've seen ones that have tracks that go over 100" and I know they're expensive, but I would use this a lot. Are there any other methods I'm not thinking of? Is the track saw way my best bet? If I used a track saw (never used one before), how does it get the edge straight? Do I need something that's already got a perfect straight edge to attach to the board for the track to follow? Any help is greatly appreciated!

[Wayne Lomman]

Others will advise you about a track saw. If you want to get this done, go to your timber supplier and look through the rack for a dead straight price of say 4 x 1 and use that as a router guide. Do matching edges by clamping both boards to your bench a little less than the cutter width apart. Clamp the guide piece on top. Use either a bearing cutter with the bearing on top or my preference is just a plain straight cutter and use the edge of the baseplate against the guide. Cheers

[Mel Fulks]

Get the material out a little longer than finished length. Get them out as straight as you can and a little wider than finished size. Run a router against a straight edge cutting a finished surface on two pieces at one time that are firmly fastened down about 3/8 inch apart. Use a new 1/2 inch router bit that is SINGLE FLUTE. It will cut fast enough to not glaze or burn the surfaces that will receive glue. This will work IF the boards are not twisted are pretty flat.

[Mark Carlson]

What Wayne said, router with a straight edge. Finding a 9 ft long plus straight edge will be the challenge.

[Mark Bolton]

Sheet of plywood as a straight edge and a router with a straight bit. Ditch the guide bearing/bushing. Youll have to scoot the straight edge for the 9' or put together a simple 9' straightedge (or make it 12' and save it for future)

[Ken Kortge]

The tracks sold via Eurekazone.com are self aligning - though a prudent person might run a tight string along the cut edge from end to end just to confirm this until you gather some confidence with it self aligning.

They self align because the grooves underneath the guide rails - where the connectors ride - and the connectors themselves have dovetail-like edges that force the connector to be perfectly centered with each use.

I like the 64" guide rail for cross cutting 4' plywood. If buy a 64" guide rail set with the SmartBase and buy another 54" guide rail you'll have 118" of track - plenty to provide a "launch pad" for the saw. You provide your own circular saw. Its quite easy to add the SmartBase to the bottom of your circular saw. It provides a VERY clean cut on both cut edges - using a regular blade - no need for a 40 tooth blade. The video below will demonstrate for you.

Once you get one straight side, then you can use the Universal Edge Guide to rip the boards to perfect width - clean edges on both sides.

Videos:

SmarttBase: https://www.youtube.com/watch?v=sSGkG17sNE8

Track Saw System: https://www.youtube.com/watch?v=-i3df2FfDgw

Universal Edge Guide: https://www.youtube.com/watch?v=8qYezPjhLqs

[Robert Engel]

Michael,

You can establish a straight edge to start with using a track saw or a good quality circular saw with a very accurate fence and a quality blade. Follow that with a hand plane to remove the saw marks, square and fine tune with either a 6, 7 or 8.

You may also get by with other means such as a straight edge guide and a pettern cutting bit. I prefer to use a length of angle iron or aluminum mounted to plywood.

Others may differ but I always follow up with the jointer plane to fine tune the joint, even when I use a jointer with boards this long.

Either way the slightest bobble or imperfection of man or machine will create errors. Check for straightness, square and twist. I do this with A 6 foot level, a square and winding sticks. I scribble the sections to be corrected with pencil nothing beats the hand plane for this.

You must do this methodically and with patience boards this thick are not very forgiving.

[Chris True]

No. 7 hand plane? :)

[Jim Dwight]

I've never joined my 102 inch track to either my 59 or 41 inch track but that is what I would do for straight, glue ready edges on 9 foot boards. I use a DeWalt but I think any of them would work, even the Grizzly if you give it a good blade. You need a straight edge to use when joining the tracks, I would probably use my 6 foot level. You also need to be a little careful with the joined track so you don't bump it out of alignment. But by taking a little care, you can do this.

Just curious but is the table 9 feet long? That is a whopper table. If the table is actually shorter, you might want to make the boards shorter before glue up. But if a 9 foot glue up is needed, a track saw can give you edges ready to glue. (Some argue that table saws do not give glue ready edges or don't without a special blade. I've never agreed with that position and I done lots of glueups that everybody who sees them thinks are fine. But if you think you need a special blade or to hand plane the edge off a table saw then you would think the same about a track saw cut edge. The cut will be the same as a good sharp blade in a table saw.)

[Tim Bueler]

I'm building a table top out of 8/4 cherry and the boards are 9' long.

That'll be pretty! What are you doing on the ends?

I'd either use a router with a straight bit against a guide or a circ saw with a good quality blade against a guide. Clean up with a hand plane if needs be. As some have said getting a good straight edge that long will be the trick.

[Mark Wooden]

Got a decent skillsaw and sharp blade?

Put your two "pretty good" edges together, clamp them down and then cut the joint with your skillsaw in the same way that Mell describes doing with a router and straight edge. Same idea, the cuts match. (Router is better though) You can then touch up with a jointer plane if needed

[Jim Barstow]

Decades ago, before I had a jointer, I had this exact problem. (My table wasn't 9' long though.) I used the router technique with a straight edge and it worked
perfectly. In fact, my "straight edge" wasn't perfectly straight but that turned out to be better, however, because it the non-straight sections matched on the boards. (Provided you cut them at the same time.) The matching imperfections in the cut sort of locked the boards in place as I glued them up.

[William Fretwell]

Jointer plane.

[Doug Bowman]

Jointer plane. yep this is what I would do

[Mike Henderson]

Jointer plane.
It would be tough to get a good edge on 8/4 material with a jointer plane, especially if the person is not experienced with jointer planes. Normally, you'd put the two pieces together and plane them both at the same time so that if you aren't straight across, the two will still match. But with 8/4 the plane is not wide enough - you'd have to do a LOT of checking as you went along, checking that the surface of the double boards is not crowned.

Then, there's the problem of getting the boards straight along the length. Even with a long plane, it's difficult to get 9 foot boards really straight. You'd have to keep taking the boards apart and putting them together to check where they were high against each other.

Given the power options suggested here, I'd sure go that route over hand tools.

And if you had a friend who has a floor mounted powered jointer, that's the way to go. Makes absolutely perfect panel joints - and does it fast. The router suggestion is really a different take on a jointer.

Mike

[Rod Sheridan]

Take the boards to your local cabinet shop.

Pay them for an hour to joint and mark your boards so you get them glued up in the correct arrangement.

Best money you'll ever spend on wood that expensive...............Regards, Rod.

[Lee Schierer]

Normally, you'd put the two pieces together and plane them both at the same time so that if you aren't straight across, the two will still match.

Mike

Correct me if I am wrong, but if you clamp two boards together as you state and plane the edges simultaneously. If I were to create a dip or bump in both boards, doesn't that dip or bump double when I put the two edges together?

[Von Bickley]

Take the boards to your local cabinet shop.

Best money you'll ever spend on wood that expensive...............Regards, Rod.

I agree 100% with Rod......

[pat warner]

I'd brick lay the surface; 2 or 3 lengths/length.
That is, get the lengths down to something your jointer (& you) can handle. Say 42" & 66".
The overlap on glue up will support all the sticks in the panel. You turn it over to the
wood shop and you're out of control, at their mercy.
Practice a little on scrap.

[Mel Fulks]

Most cabinet shop jointers are not kept adjusted well and will produce slightly convex (open end) joints. Get a price quote then tell them you will not accept open end joints. Then you will hear "well,that don't hurt nothin' " and a higher quote. Do not allow them to do the gluing.

[Malcolm McLeod]

Michael, where are you located? Perhaps I can help (12" jointer and table saw).

[Brian Holcombe]

I use hand planes for this work, but I have experience to know how to tune and edge, it's not simple work for someone who has never used a hand plane. When I'm gluing up a long pair of boards, I clamp one in my vise, and then plane the edge flat, checking it with winding sticks to ensure that it is true. I can see straight (meaning I can see if the edge has a curve or hollow), so I will do 90% of it visually, then use my straightedge to find tune the remainder.

I put that board aside, then do the same on the adjoining board. That gets me close, at that point I will stack one upon the other (one is tight in the vise) and check for a rocking motion, and look for gaps. Continue tuning until the two boards are tight.

The router idea will not work, it is incredibly unlikely that the two faces are completely free of twist along their length (9') so the reference (wide face) will transfer that unevenness to the edge, the result is an edge that will not fit right.

What you should do is find a local yard or shop that has a going machine jointer and pay them an hours rate to have them joint the boards for you.

[Mike Henderson]

Correct me if I am wrong, but if you clamp two boards together as you state and plane the edges simultaneously. If I were to create a dip or bump in both boards, doesn't that dip or bump double when I put the two edges together?
Absolutely. But that's a problem along the length. What clamping them together tries of correct for is if the edge is not perfectly straight across. So let's say that the edge is not 90 degrees across, but is 92 degrees. Both boards will have the same "error". If you put them together correctly (basically just fold the boards over), the angles will match and you won't have a gap on one side of the board. If you did them separately, if one board is 90 degrees and the other is 92 degrees, you'll have a gap on one side when you put them together.

If you do them separately, both edges have to be perfect for them to fit and that's tough with an hand plane, especially for a beginner.

The problem you raise is a problem along the length of the board, and putting two boards together will not help that. You have to use a long jointer plane to try to get a straight edge. One way to check for that is to take the boards and put them together and see if they fit. If not, mark the high spots and focus on that for the length.

Before I bought an 8" powered jointer, I used to joint my lumber by hand. It's difficult and takes a long time when the boards are long like his (9 feet). A powered jointer is soooo much faster and more accurate.

Mike

[Because his boards are 8/4, you can't plane two of them together as I described. Hand planes are not that wide. That technique is for 3/4" boards (or less).]

[Jim Dwight]

I've tried a bunch of blades in my Milwaukee circular saw and I used it with a guide but I never got what I would consider glue up ready cuts with it. Somebody more skilled than I am could have quickly cleaned up the cut with a plane but I would not consider any circular saw cut I have seen good enough to go direct to glue up. Too rough. But I've used table saw and track saw cut edges very satisfactorily.

I have a jointer too but it is an Inca with pretty short tables. I get better results with the saws but some is me not using the jointer as effectively as I'm sure others could. With a really long jointer, I think it's easier to get straight edges.

[John T Barker]

No. 7 hand plane? :)

Find out how old the guy is first...that would kill me.

[John T Barker]

Any professional shops in your area. When I moved to Pa. and started in woodworking we were often getting local woodworkers coming in with challenges like this. The foreman would give it to one of the low guys who would make a couple of easy bucks doing whatever the job was.

[Brian Holcombe]

Find out how old the guy is first...that would kill me.

Jointing an edge is not hard (physically).