Can I joint the edge of plywood?

[Dick Snyder]

I am a new jointer owner so I haven't tried this yet. I am going to laminate some curly maple veneer on 1/2" baltic birch plywood. When it is all done, I need to have a very straight edge. Can I run that edge over my jointer? I thought I would clamp another piece of wood over the veneer to make sure it wasn't torn by the jointer knives but will I get into problems running the plywood over the jointer? I could always experiement but this veneer is expensive so I thought I would check with the group for some ideas before trying it.

TIA.

Dick SNyder

[Jay Pique]

You can, but you'll ruin your steel knives right quick. The glue is so hard it'll leave little ridges in the blades. Unless you have carbide, you don't want to do it. What you can do is joint it on your router table, by shimming the outfeed side of the fence out. The carbide is tough enough to stand up to the glue. The ideal thing would be to cut it straight first, then just flush trim the veneer.

JP

[Dick Snyder]

You can, but you'll ruin your steel knives right quick. The glue is so hard it'll leave little ridges in the blades. Unless you have carbide, you don't want to do it. What you can do is joint it on your router table, by shimming the outfeed side of the fence out. The carbide is tough enough to stand up to the glue. The ideal thing would be to cut it straight first, then just flush trim the veneer.

JP

[J. Clarke]

Clamp against the fence a straight board long enough that two points on the work piece will ride on it. Cut one edge. You now have a straight edge. Use that one against the fence to cut the other.

[Bored Borg]

On Sun, 9 Nov 2008 13:21:56 +0000, J. Clarke wrote (in article ):

How do I get the first long board straight... ?

Do I need an even longer board?

How do I get THAT straight... ?

:-)

[J. Clarke]

Since it's not plywood you do it on the jointer.

[Morris Dovey]

I have an 8' and a 20' length of _straight_ alumin(i)um angle in my shop to solve exactly that problem. :-)

[John Grossbohlin]

Hard to say specifically without knowing how long your plywood is... If it's relatively short compared to your fence, cutting one side and then cutting the opposite side is usually sufficient. If it's relatively long, a long straight edge clamped to your fence will let you cut one edge, then cut the opposite edge. You may want to plan on cutting the first edge again if you didn't cut the pieces to rough size initially. A steel stud would suffice for a straight edge for the initial cut.

I'd avoid jointing the edge of plywood. I have face planed ACX and BCX for use in making shop cabinets to get uniform thickness with success but edges are tough on the knives and tend to blow up.

John

[Dick Snyder]

OK - I can see how this would work for me. The plywood I have is 31" x 24". I have a 48" long level which I can clamp along the fence. Then I can run the plywood against it.

Thanks.

Dick

[Robatoy]

[Morris Dovey]

The twenty-footer is "pretty danged straight", so - since you haven't said ±0.002 of /what/ units, I'll assume AU - I'll say: "Yeah, sure!" Pretty good, eh?

The eight-footer (being only 8 feet long) isn't /anything/ over 12 feet. :-)

Best of all, the cost was under $1/foot.

[Robatoy]

happy with that. It is wide enough that I can use a router on top with a trimmed bushing. It is straight enough for all practical purposes if I don't lean into it too much.

[Charlie Groh]

...this is one of those techniques that may be frowned upon, but I use an old, straight, level that I've decommissioned from the bubble jobs, I eyeball the crown of whatever I'm trying to straighten/joint (a good example is S2S hardwood I buy 'cause it's cheaper), put the concave side against the straightedge and *that* against the fence (that is set to maxamize the width of the board), using a deadman that is the same height as my table to hold everything steady...whew... I then run the package through the saw. This method took me a few trys, mainly getting my feet to move properly and at the same time holding the level against the fence, resulting in making the cut in pretty much one, smooth motion. Naturally, after the initial pass, I flip the board and cut the concave side flat. It works for me and I usually dont do lengths over 10', but it may not be everyone's cup of gasoline...

cg

[Charlie Groh]

...you'll need a smidge more straightedge to cover the outfeed even if your cutting the short side...

cg

[Gary A in KC]

My own technique is a "sandwich" that I use on the tablesaw. I've got 2 - 5 foot long by 1 foot wide pieces of mdf. Milled straight on my table saw. I drill 1/2" dowels through one and half way through the other to index them into a sandwich. The dowels protude about an inch above the top piece. When I need a straight edge on a newly veneered panel, I just put the panel between the 2 mdf pieces and make a sandwich. The panel sticks out one side and the mdf provides the straight edge to run against the saw fence. Just get the panel square inside the sandwich (easy to do) and you've got what you need. The other use for the sandwich is also for veneering. When I'm doing bookmatches of veneers and need to joint the edges, I put the packet of veneers in the sandwich, clamp it really tight and flat, then run a laminate trimmer along the edge and take off an 1/8" or so to get perfect edges.

Gary in KC

[sheldon.mandel]

I make a sled out of a piece of flat stock. The stock is 3/4 pine (yes, it's straight!), 48 x 8. I countersunk 2 holes in it for aluminum hold-downs, and use them to control the piece to be jointed. I use the hold-downs as handles.

make sure the piece is just ver the edge of the sled.

shelly

[-MIKE-]

Today. :-)

[RM MS]

2-way tape a long steel scale or other known straight edge to one side and run this against the saw fence. Then saw the other side off. Now flip it over, remove the straight edge & tape, and saw it to size.