Screws in soft wood

HannaFate

SPFG, Supreme Picture Framing God
Joined
Apr 29, 2002
Posts
10,688
Loc
Corrales, New Mexico
This is such a simple thing, but I haven't seen it mentioned anywhere, so here it is.

When screwing your mounting point for a wire into soft wood, you can reinforce the point with glue.
Make a pilot hole with the tip of an awl, and put some plain white glue in the hole before screwing in the screw. This reinforces the wood fibers around the screw, and makes it less likely to rip out.

I usually use two-screw plates on soft wood, to distribute the strain, but even so, really soft moldings on heavy pieces can be a problem. I recently solved such a challenge by framing a large piece with the thinnest metal frame I could find, then mounting the soft wood molding on top of it. (hot glue is a wonderful thing!) The wood bears no weight, so I could use the ridiculously flimsy molding the customer wanted on a jersy. (with glass, not plexi)
 
Your use of a metal frame behind a too thin wood frame is a very clever solution.
Here is a web page with the proper size pilot drill sizes and clearance (shank) drill sizes for both soft and hard wood frames <http://www.internetwoodworking.com/w5/screws.html>
An awl will not make the proper size, shape, or depth of a pilot hole. Wood glue will not help the shear strength of a screw in wood. A proper diameter drill hole will help prevent the frame from splitting. The use of screws in wood in a "pull-out" or tensile mode should be avoided.
You can minimize the forces on the wire and screws by hanging your picture on 2 hooks spaced almost as far apart as the frame is wide. If your picture weighs 10 pounds, the pull on each side of the frame will be about 6 pounds almost straight up with hardly any stress on the frame.
 
The trick is to get the customer to USE two hooks. I have had customers bring back frames all busted up, and tell me, "It just fell off the wall!". I look at the back, and the hooks I gave them are still stapled to the wire. There is a kink in the middle of the wire, and it is plain that they hung it on one nail. Someone bumped it, and it slid across the nail, gaining speed, and *SPANG!* thump.

What the glue does is gives the poor thing a chance to hang on while an inept customer pulls the frame off the hook toward themselves, yanking on the wire. I wouldn't expect it to hold under sustained stress.

Thanks for the link, with more information!
 
Hanna,

The reason being that you just don't "screw" with tropical snotwood!!


I would stick with your metal moulding solution. That is a good idea and the bottom line is sometimes you gotta go with whatever works for you.

Framerguy
 
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