Screw into edge of plywood?

[Kent A Bathurst]

I know not to put screws into endgrain of solid wood (unless drill and insert dowel to receive the screw).

But - can I screw into the edge of plywood?

[frank shic]

absolutely although you may wish to predrill the receiving hole so you don't get as much bulging.

[Kent A Bathurst]

Oh man - talk about lessons learned!! I (a) always drill pilot holes, and (b) drive and remove steel screw to cut threads b4 driving brass, and (c) wax screws going into hardwood. Got a few "slap upside the head" lessons on the way to those rules.

Thnx, Frank

edit: Oh, yeah - and (d) never never NEVER reuse a screw that went into hardwood, or is going into anything that can be seen.

[Leo Graywacz]

Why can't you put screws into the end of solid wood?

[frank shic]

he meant without predrilling i believe

[Kent A Bathurst]

Why can't you put screws into the end of solid wood?

Well, uh, I had always read that screwing into endgrain wasn't wise, because the fibers don't have nearly the holding power that they do perpendicular to the grain. And, since I am self-taught, using FWW, reference materials, etc., I just figured everyone else was a lot smarter at this than I was. Betcha for low-structural applications it would be fine.

[Leo Graywacz]

Predrill and use the proper thread on the screw. If you are going into end grain in a soft wood you need to use a coarse threaded screw. You might also have to use a longer screw to get the holding power you require. Most of the screws I use are self drilling so I don't usually need to predrill.

[Eric Gustafson]

When I screw into the edge of plywood, I almost always have the edge captured in a dado. That way there is no splitting of the plys.

[johnny means]

[QUOTE=Kent A Bathurst;1224674 I just figured everyone else was a lot smarter at this than I was. [/QUOTE]

You would probably be wrong there. 99% of these people are just regurgitating what they read in some publication.

Magazines and other literature are a great tool to learn from, but one should question "common knowledge" and analyze situations before saying it cannot be done or accepting someone else's statement as gospel.

It's all about going about it the right way. With the proper approach MDF can hold a screw in the edge.

[Kent A Bathurst]

When I screw into the edge of plywood, I almost always have the edge captured in a dado. That way there is no splitting of the plys.

Yeah - that makes sense. I'm in a situation where that isn't an option, but will keep it in mind for next time.

[Rick Fisher]

When I worry about holding power, I dip the screw in yellow glue before inserting.. My theroy is that the wood fiber swells around the screw, holding it better..

I have zero proof that this works... but I still do it.

[Matt Armstrong]

When I worry about holding power, I dip the screw in yellow glue before inserting.. My theroy is that the wood fiber swells around the screw, holding it better..

I have zero proof that this works... but I still do it.

I'm almost positive the glue is wiped off the threads by the wood fibers on insertion, but I've got my quirks too...

[Tony Bilello]

You would probably be wrong there. 99% of these people are just regurgitating what they read in some publication.

Magazines and other literature are a great tool to learn from, but one should question "common knowledge" and analyze situations before saying it cannot be done or accepting someone else's statement as gospel.

It's all about going about it the right way. With the proper approach MDF can hold a screw in the edge.

I'm glad someone finally said it.

Now back to the original question:
"I know not to put screws into endgrain of solid wood (unless drill and insert dowel to receive the screw)." Well, That depends...If you drill a hole in the end of a board and insert a dowel into that hole, all you have done is swap the kind of wood you are screwing into. That is because you are still screwing into end grain. If on the other hand, you drilled a hole into the board from the side or top of the board and inserted a dowel you in effect have placed the dowel in a position so that a screw driven into the end of the board will pierce the dowel in it's long grain orientation which has better holding power.
"But - can I screw into the edge of plywood?" There is an additional problem with screwing into end of plywood. Not only do you have less holding power but you also have a problem with separating the plies. This is less likely to happen with a good quality hardwood or Baltic Birch plywood but still likely to happen.

Do woodworkers including myself occasionally screw into the ends of solid wood and plywood? Yes, but you didn't hear it from me, and I'm sticking to that story.
I always predrill the hole first to alleviate the stresses that cause splitting or delamination. Keep in mind, that this is a pretty weak attachment and should also always be glued. It is much much better to glue the joint and use a brad nailer with fairly long nails if you have an air nailer and compressor. If you dont, get one!!!!

[Larry Edgerton]

When I worry about holding power, I dip the screw in yellow glue before inserting.. My theroy is that the wood fiber swells around the screw, holding it better..

I have zero proof that this works... but I still do it.

Rick, I do something simular, in situations where holding power is in question such as soft wood or mdf I use a syringe with west system in it and put two or three drops in the predrilled hole before the screw. This adds strength the whole area around the screw as the epoxy is forced outward by hydraulic pressure and soaks in quite far, sort of like a threaded insert. If it needs to come back apart I spray the screws with TopCote first.

[Kent A Bathurst]

I'm glad someone finally said it.

Now back to the original question:
"I know not to put screws into endgrain of solid wood (unless drill and insert dowel to receive the screw)." .....end of the board will pierce the dowel in it's long grain orientation which has better holding power.
"But - can I screw into the edge of plywood?" ......less holding power but you also have a problem with separating the plies...........

It is much much better to glue the joint and use a brad nailer with fairly long nails if you have an air nailer and compressor. If you dont, get one!!!!

Tony - thanks - comprehensive answer - very helpful -
>> dowels - didn't explain myself in OP, but this was exactly what I meant and what I do
>> edge of plywood - this is pretty much what I was thinking
>> air nailer/etc. Got plenty of those critters, but won't work in this application

I have (veneered) plywood sides and a solid wood top. Everything is designed and built to allow for wood movement. I will glue the sides' tenons into the first inch of the top's dadoes, and at the back I am going to use those "figure 8" clips (don't know their real name) for movement. My question relates to the screws into the ply sides to hold the clips.

It is a small desktop printer stand. The screws in question wouldn't have more than 5lb stress/load on them even if someone grabbed the thing by the overhang top and lifted - So I think I'm good with the screws into the edge. One of those things where I just grabbed some wood and wnet to town, then realized I had not thought this one detail through - difficult, but not impossible, to get the long-grain dowels in there at this point.