Help with cab door hinges

[JohnW]

I built a solid cherry kitchen several years ago and used Blum compact concealed soft close hinges which worked out very well. My son and I are now building new doors for his kitchen. Not new boxes, just simple flat panel doors with poplar frame and plywood panels. All will be painted.

His "boxes" are built-in plywood so the compact hinges would be screwed into the edge of plywood. My solid cherry frames held the screws very well but I'm wondering if attaching the hinges into the end section of plywood is ok. Ply holds screws well when they are face mounted but will the ply (looks like birch) hold screws when installed on the 3/4 edge?

Hidden GLOAT here is that my +30 year old son is helping me build his doors. First time he has used a jointer, plainer, table saw etc...and he's really enjoying the into to woodworking.

 

[Skymaster]

go to a frameless hinge which mounts onto the SIDE of the case. hinge pattern is the same on the door, different pattern for the case mount. Blum has a jig which costs a few bucks BUT makes life sooooooooooooooooooo EZ. Go CLIP ON

 

[JohnW]

What I'd like is experienced opinions on using screws directly into the end of plywood. Is that something to stay away from?

Jack,
Don't think I can used a CLIP or frameless hinges. The built in case is already made...just making doors and the cases have what amounts to a face frame while other door openings don't have a case or side wall anywhere close to the opening. As I understand cabinet construction, which I have limited experience with, I will need to attach any concealed hinge to the edge of the frame. If that's not a good idea, I'll look for an alternate style of hinge.

 

[JohnnyR]

Screwing into the side of plywood is a bad idea. You're asking for failure. Hard to follow exactly what you've got but you may have to buy different hinges for different cabinets. Go to Blum's website and you'll find detailed info on a plethora of concealed hinges. If your only choice is to screw into the end, I would rout out the end of the plywood and glue a solid plug into it so the screw has something solid to grab. Not sure how easy that would be on installed "boxes" but you could probably fashion a mortice jig to clamp on. Good luck with your mentoring - I'm doing the same with my daughters boyfriend.

 

[Stuart Kent]

agreed, don't screw into the edge of plywood as it will fail. There are many hinge options available, keep looking and you will find one that works.

 

[Jeff]

What type of hinge mounting systems were on the old overlay cabinet doors? Time for a change with a different mounting system and hinge style?

The existing cabinets have 3/4" plywood face frames? Correct? Mounting the hinges on a plywood edge is risky but doable without a disaster; pre-drill the holes undersize and use fine thread screws. Your new doors are not gonna be that heavy so the screws in the edge mount configuration may hold just fine.

Blum offers another configuration that may be a better option; the mounting plate attaches to the face of the cabinet. Maybe a voila?

http://www.hardwaresource.com/hinge...on/european-hinges/all-about-european-hinges/

 

[JohnW]

Thanks Jeff,
I didn't see the Compact 33 face mount on the Blum site but thanks to you I see it now. The 1-3/8" overlay may be an issue as our design calls for 1/2" OL...but I'll run that trade off by my son. I think I'll stay away from edge mounting any hinge.

Thanks all for your advice.

 

[ehpoole]

As others have pointed out, you should go to most any length possible to avoid driving hinge screws into the edge of a plywood panel as it places the greatest stress directly at plywood's weakest possible point.

If for some reason you absolutely *must* use such a hinge it is critical to pre-drill the pilot holes with a carefully chosen pilot diameter so that the threads bite into the wood well but the body of the screw does not wedge the laminations apart. Then you must use unreasonably long screws (several inches or more) so that the forces on the plies are distributed over as great an area as possible, then tighten things down quite tightly (but not so tightly as to risk shearing your screws).

It can be done, but it is one of those areas that tends to receive a lot of stress at the plywood's weakest point, which will nearly always lead to premature failure (ply delamination) versus properly securing the hinge to the plywood's face, where it has the greatest strength and resistance to pullout and delamination. Using carefully sized pilot holes and very long screws can help a great deal, but it is far from ideal and there is still a risk of eventual delamination.