What angle should screws be with a 45d gallow shelf brackets?

[ziplock9000]

Should they be perpendicular to the L part (A), perpendicular to the angled part (B), or somewhere between?

 

[Yojevol]

A, but not the easiest to achieve in practice

 

[Bingy man]

Also A - depends on the timber dimensions but as long as you pre drill, and glue the components it should be fine . Counter sinking is probably the hardest part so your choice of screws will be important.

 

[Sgian Dubh]

Should they be perpendicular to the L part (A), perpendicular to the angled part (B), or somewhere between?

Perpendicular, but inserted from the other direction to the one you've indicated if at all possible, i.e., screw through from the back face of the vertical member into the angled brace. This method is possible if the bracket is manufactured prior to it being attached to the wall. Slainte.

 

[macca]

OK if timber locks but IMO standard screws are the wrong fastening for this job, the force compresses joints at both ends, which hopefully are mortice and tenon ( in which case you dont really need screws) but if you do not have a M+T here then you are trying to stop the diagonal brace from moving down the vertical timber, screws sheer under this type of force, their job is to pull together, this is done by the roof pushing down on the bracket. Nails stand up much better in this situation or best of all a coach bolt.

Just my opinion but long story short: screws pull and you dont need pulling, they also snap easier.

 

[Cabinetman]

If it were me I would just use a couple of halving joints without screws or nails, a dab of glue if you want but it will hold just fine without. Can do you a sketch if needed.
Ian

 

[skeetstar]

As per SD's recommendation, glue it first, then clamp it to avoid movement and put the screw in from the rear face.

 

[johnnyb]

Mortice and tenon forget screws

 

[Jameshow]

Mortice and tenon forget screws

Wedged of course!

 

[Cabinetman]

Tusks lol

 

[Jameshow]

Tusks lol

Only if the back is exposed?!

 

[Cabinetman]

Where the tenon goes right through the wall perfect place for a tusk haha, better than plastic plugs!

 

[johnnyb]

I'm not sure wedging would add much to this. A screw could hold the m and t together OK. But the strength is in the tenon shoulders also the length of wood fibre resisting so always have the longest you can on the outside of the tenons.

 

[trvlr]

perhaps notch the lower edge/end of brace into the vertical section so as to limit its tendency to want to slide down - for whatever reason, and regardless of how that brace is otherwise attached?

 

[RupertV]

perhaps notch the lower edge/end of brace into the vertical section so as to limit its tendency to want to slide down - for whatever reason, and regardless of how that brace is otherwise attached?

Yep, that is how I was taught to do it, certainly if there is considerable weight involved such as a porch canopy. More skill needed than just a chop saw ,glue and screws/nails.

 

[Orraloon]

perhaps notch the lower edge/end of brace into the vertical section so as to limit its tendency to want to slide down - for whatever reason, and regardless of how that brace is otherwise attached?

Good advice but notch both ends of the brace then gravity holds it all together. Then a wooden pin either end to keep things in place. Will look better than screw heads showing plus be way stronger.
Regards
John