What is going on here? Gap between boards.

Re: What is going on here? Gap between boards.

Barry Irby

They appear to be bowed. Try reversing one end for end and see what happens.

They appear to tight on the two ends, but it might be that your saw is not at a perfect ninety degree angle to the table. If reversing them does not help, try ripping one face up and one face down to cancel out any discrepancy in your saw.

I do that on my jointer. Even though the fence is as good as I can get it, reversing the cuts seems to help. Might just be that it keeps my mind on things.

If you can get the gap to half that size you can call it a sprung joint and glue it up.

Re: What is going on here? Gap between boards.

Jesse Cloud

First thing I would do is to see if both boards have a problem or if its just one board.

Set the edge of each board on your jointer or other dead flat space. The bow should be obvious.

If its just one, and you can spare some width, rip off a bit of the offending side, especially if there is some funky grain pattern going on, then joint until flat.

If your panel is extra wide at this time, and the pattern you have chosen is not critical, you might move the offending board so that the funky edge is on one end and trim that to the desired final width.

Re: What is going on here? Gap between boards.

Dick Coers

How straight is the rip fence? I always joint after ripping, I prefer that surface finish. Could be a dull blade and the way you are feeding it through the saw. Lots of variables, but sharpness is my #1 fix.

Re: What is going on here? Gap between boards.

Steve jenkins

It looks to me like number 5 is bowed. Tight to 4 on the ends and gapped to 6 on the ends. If you have A jointer try taking one pass off each end on the left side then a full length pass off the same edge. See if that closes it up to 4. If so then rip the opposite edge on the saw.

Re: What is going on here? Gap between boards.

Jim Dillon

Joe, I'm assuming you joint one edge of each board prior to placing that jointed edge against the TS fence, then ripping to width. Is it possible that the jointed edge is not perfectly flat along its entire length? Uneven downward pressure at the start and finish of the jointing process (compared to the middle) would give you the result you observe especially when you exert sideways pressure on the board to keep it snug to the TS fence. Just a thought. Uneven feed speed on the TS leading to blade wobble could also produce what you are seeing. As Dick suggested, I also try to do a very light jointing of the ripped edge and allow for that extra step by setting the "final" TS width to just a hair wider than the final width should be. Or as Barry suggested, make lemonade from lemons and call it a sprung joint . I won't tell anyone! Jim

I don't understand either

Bill Tindall, E.Tn.

While removing a convex edge can be a challenge with a jointer, removing a concave edge is trivial.

Step one: find out what edge is not straight buy butting various edges together to see which butt well and which don't and in what way they are off.

If one edge is concave, as it looks to me, run this edge over the jointer. It will become straight. If not, you have performed a miracle.

I have heard it claimed that a sprung joint can be made with a jointer but never understood the claim nor the physics that would produce it.

If all else fails hand plane it straight. I occasionally have to resort to this solution with convex edges.

Re: What is going on here? Gap between boards.

Don Stephan

First, a pairwise matching of all of the edges would be helpful, to determine how many are perfectly straight for their entire length.

He does not mention owning a jointer....

Barry Irby

Said he ripped them several times on the TS. If he had a jointer to use I suspect he would have tried that, but I think he is trying to do this with some sort of glue line rip blade. Never had much luck with those myself, but then I own a jointer.

Sprung joints are easy on a jointer. Set the depth of cut to about a 1/32". Put the lead end just past the cutterhead onto the outfeed table, press down firmly and joint to the middle. Turn it around and do the same thing, making sure to get to the first cut or overlap a little. If you started with a straight board, it will end up "sprung".

If you have a concave or sprung board, you can start in the middle and joint it both ways to knock the "high" ends off.

Re: What is going on here? Gap between boards.

Brian Holcombe

#5 is curved, sometimes things move after you joint one edge then rip the other and in this case things moved.

Re: What is going on here? Gap between boards.

Brian Holcombe

Unless you're planning to glue these all at once, I would clamp up 4&5 and see if clamping them closes the gap. If it does, I would glue them.

After which I would check 5 against 6 and 4 against 3 and see how they mate up. If they're gapping and the gaps aren't able to be clamped out then I would joint the edges and try again.

By clamp out, I mean with a fair amount of pressure, not a ton of pressure.

Re: I don't understand either

Brian Holcombe

Bill,

On some jointers you can lower the heel of the infeed table to create a curved edge.