Will Screws into the end of plywood hold?

[George Bokros]

I need to draw a tongue and dado joint together while the glue sets, will screws driven into the end of ply provide holding power or am I wasting my time and risking splitting the ply? This is two pieces of 3/4" ply laminated together. I would pre-drill the holes.

Thoughts / opinions

[Jamie Buxton]

You'll be fine, especially since you're drilling pilot holes for the screws.

One way to get more holding power from screws into end grain is to make the screws longer.

[Myk Rian]

One way to get more holding power from screws into end grain is to make the screws longer.
Or use longer screws.

[Hoang N Nguyen]

It will hold. I built my table saw out-feed table legs using 3/4" birch ply from the BORG and it's solid. Glue in between, pre-drill and countersink the holes and you'll be fine.

[Mike Heidrick]

Cant use a clamp?

[George Bokros]

Cant use a clamp?


No. I do not have a clamp long enough, 8 ft. Also on one end a clamp would not have enough jaw depth like 5".

[Peter Quinn]

I do it all the time. Good coarse thread assembly screws, no problem, very tenacious bond with glue involved. Only half the layers are end grain...the other half are edge grain, so you always get something. I usually tack things together with a few 18ga brads then pull it down with screws. Only time I use clamps is if the ends are exposed finished ends or the plywood has some particular bow to it that requires clamps to pull out and square up. Never say you don't have clamps long enough, lots of ways to join/stretch/extend your clamps with cauls, or dead men, or just a long 2X4 with a block at one end to hook like a clamp head and a notch to hold a clamp at he other. You could clamp a 10' case with a 12" clamp that way. But not necessary for most plywood carcuses.

[Keith Weber]

I like Spax screws for times when I'm concerned about holding power. I buy them at Menards, but I'd guess that you could get them at the other big box hardware stores as well.

[Doug Hepler]

http://www.finewoodworking.com/cms/uploadedimages/images/woodworking/uploadedimages/Fine_Woodworking_Network/Image_Resources/Magazine/245/011245014_03_clamp-extension_xl.jpg

[Peter Quinn]

http://www.finewoodworking.com/cms/uploadedimages/images/woodworking/uploadedimages/Fine_Woodworking_Network/Image_Resources/Magazine/245/011245014_03_clamp-extension_xl.jpg
thats what I'm talking about! You see things like that in some old school wood working texts from a time when iron was expensive and wood cheap!

[Bob Michaels]

OT, but Doug, that was worth a thousand words. Was that done in sketchup ? How did you get the "sketch" look instead of perfect lines. I like it.

[Doug Hepler]

Bob,
I am flattered by your assumption, but I did not draw that. I searched for "clamp extension" or something like that on Google and copied the best drawing I found. It's apparently professionally drawn to illustrate a magazine article.

Doug

[johnny means]

Actually, that is an option on Sketchup. Simply change the line style.

[Robert Engel]

Not quite getting the terminology.

Are you talking about a tongue and groove joint or a board into a dado like a shelving unit?

If a tongue and groove, you can clamp it many ways. One example shown.
You can also use 2x4" with a cleat and wedges.

If the latter, you will want to screw it anyway I wouldn't rely on edge gluing plywood.

Either way, yes, any coarse thread screw, even a drywall screw will work just have 1 1/2" penetration.
Make sure you drill a pilot hole