straight-line rip of long boards on cabinet saw - looking for ideas

[scott vroom]

I typically purchase lumber already straight lined on one edge. My latest project involves rough 5/4 and most of the 10' boards have a slight bow on both edges. In the past when I've done this I've used a narrow strip of 8' x 3/4" plywood as a sled with hold downs to hold the bowed stock then straighten one edge by sliding the plywood jig against the fence...rudimentary but worked OK. I no longer have that jig am am wondering, before I make up a new one, whether I might get some better ideas on how to do this with a cabinet saw (I don't have a track saw and have no interest in purchasing one).

[Judson Green]

Do ya have a circular saw? You could make a down a dirty track for it.

[scott vroom]

Do ya have a circular saw? You could make a down a dirty track for it.

I have a circular saw but my longest steel straight edge is only 6' and I have all 10' boards to straight line. I could use an 8' plywood strip as a straight edge but have 8 boards to do and would have to do a separate setup on each board, whereas the ply sled on the table saw is a one time setup, then just swap out the boards to be straight lined.

[Ray Newman]

Your original jig is the way to go.Fabricate another one and it will be close at hand should need arise again.

[scott vroom]

I've got an 8' x 12" x 3/4" MDF panel but I don't have any extra hold down clamps so I'm gonna screw 4 or 5 1" L brackets onto the MDF then a narrow screw into the center edge of the board to be straight-lined. I'm moving into a 1,200 sq ft shop next year with room for a slider....this will get me by 'till then.

[Jerry Wright]

Forty years agi, I straightened one edge of long walnut boards by burying a small part of the table saw blade in a cove board attached to the rip fence. You can safely remove almost an eigth of an inch in a pass. It goes quickly and you can sneak up on a straight line just like you would on a jointer.

Jerry

Jerry

[Myk Rian]

A jointer will work.

[scott vroom]

A jointer will work.

Not a 10' board on a 6' jointer table...think about it.

[Bill Orbine]

Not a 10' board on a 6' jointer table...think about it.

Huh??? The jointer will work if properly set up! I've done 16' boards on a 6' jointer!

[scott vroom]

Huh??? The jointer will work if properly set up! I've done 16' boards on a 6' jointer!

16' bowed boards? How?

[Peter Quinn]

Huh??? The jointer will work if properly set up! I've done 16' boards on a 6' jointer!

Thats just crazy talk. Its tough to put a straight edge on 16' material with a 108" long jointer even after coming off a straight line saw, and I've done it enough to know. Straightish...maybe. But when you need to make glue line edges on long boards, its rough, and you can loose a lot of width. If there's a magic formula its news to me and many colleagues with formidable experience. You might get 10' straight, but if its a big pile that gets old fast.

[Bill Orbine]

Imagine if you will..... you have a jointer plane (yes, the hand held kind). You start shooting off high spots of the board while it clamped to a bench side or something. You keep truing up until you a least have a nice eyeball straight. It's not going to be 100% true, but good enough the eyeball has trouble seeing anything. Now, with a 16' board on a jointer machine.... I need help supporting the ends. Usually one other person or two stands. But a human help is easier. 10 foot boards.... much easier and I can usually do on my own. So on the jointer... start by shooting off the high spots .... the bow ...or the cup. Move along till you get it reasonably straight... then take a full length pass.

Usually, after getting the first board straight, I use that board to true up all the others with the table saw.

[sean schriver]

Huh??? The jointer will work if properly set up! I've done 16' boards on a 6' jointer!

I second that. a former employer showed me how to nib off the toe and heal on the concave side first then make your final passes. Or, I've see him use the convex side and holding equal pressure on either side of the board, starting with creating a flat in the middle and gradually running more and more of the the middle until you've reached the toe and heel then making your final passes. before getting my 8 inch jointer, I used to have to have everything straightline ripped,...not any more thanks to the jointer and watching my boss....

[scott vroom]

I second that. a former employer showed me how to nib off the toe and heal on the concave side first then make your final passes. Or, I've see him use the convex side and holding equal pressure on either side of the board, starting with creating a flat in the middle and gradually running more and more of the the middle until you've reached the toe and heel then making your final passes. before getting my 8 inch jointer, I used to have to have everything straightline ripped,...not any more thanks to the jointer and watching my boss....

Sure, you can do it. But why would you when a single straight line cut on a simple TS sled does the job? I had 10' 5/4 boards weighing 28-30 lbs that were as much as 3/4" crooked. I cannot envision how "nibbing off" 3/4" at 1/16" per pass times 2 ends on a board of that size and weight could possibly be easier than a single pass cut on a table saw.

[Tom M King]

Not a 10' board on a 6' jointer table...think about it.

I do it all the time. Even 16 footers once in a while, but I do have a couple of very strong helpers that are used to working with me.