Q: Marking out for knife hinge

[Aram]

The cabinet I am building (in my build-along post) will have an inset door, about 5" wide, >8" tall. I'm using Brusso L-shaped knife hinges. I have never used knife hinges before.

The cabinet is dry fitted and clamped. I want to mark the hinge outlines with the case assembled, and then mortise them after disassembly. I have a kind of silly question. How do I mark the top?

I have fitted box hinges by hand before, with very good results. So I am comfortable aligning, marking, and chiseling or hand routing. With the right spacers, I think it will be easy to do this on the bottom. But holding the top hinge, while marking it from the bottom, seems unwieldy and a little risky (hinge might move during marking). I could flip the cabinet upside down, but it's awkward with all the clamps on it. I'd prefer not to. But will if I have to.

Any suggestions?

[Phil S.]

Here's what Brusso has to say about it -

https://www.brusso.com/pivot-hinge-documentation/

[Aram]

Here's what Brusso has to say about it -

https://www.brusso.com/pivot-hinge-documentation/

Thank you. I had seen that. My question is more about the practical limitations of marking upside down.

[GeeDub]

Not being a smarty here.  If you can't disassemble the top to flip it over I would flip the whole piece.  A neighbor and a beer can help with this.  Another thing that might help is the method I use even when I mark prior to assembly; double stick tape.  Be diligent with your layout.  There's not a lot of fudge-factor with these.

   

   

I use pencil to make returning the hinge/tape to position more reliable.

   

   

The tape along with one finger's pressure gives me Super-Strength while marking with a knife.

   

   

I use a Dremel with a plunge base to hog out the spoil.  The hinge works to set the depth perfectly. I clean up to the line with a chisel and gouge.

   

   

   

I find the tape's grip to be a real asset when marking.  This may solve your upside down problem and save you a beer.

[Aram]

Not being a smarty here.  If you can't disassemble the top to flip it over I would flip the whole piece.  A neighbor and a beer can help with this.  Another thing that might help is the method I use even when I mark prior to assembly; double stick tape.  Be diligent with your layout.  There's not a lot of fudge-factor with these.

Thanks, GD. Probably right. I've flipped it once already. It's small for a cabinet, just unwieldy with clamps on it. But it's easy enough to take the clamps off, flip it, and re-clamp.

[Handplanesandmore]

"I could flip the cabinet upside down, but it's awkward with all the clamps on it. I'd prefer not to. But will if I have to."
What joinery do you use? How many clamps are we talking about here? 4 is what comes to mind...and it should be simply to take off the clamps, flip the case, and reclamp. No?

https://www.popularwoodworking.com/proje...fe-hinges/

The best explanation I've come across, even better than how Krenov laid it out in his book.

By the way, hinge (not just knife kind) bloopers are easy to fix if they happen. Fill the mortise with epoxy wood putty and redo the layout and mortising after it's completely cured. Make sure you dry fit everything before gluing up the carcase...much easier to remortise anything by taking the top or bottom or the doors apart.

Simon