Cross-grain Trim Attachment

[Philip1231]

I thought I would mention something about attaching trim to the side of a case, which results in cross-grain attachment.  
Using a dovetailed key, the trim is free to move independent of the side of the carcass. It was not as difficult as I had imagined it would be.  A new tool in my woodworking arsenal.  

   

   

   

   

[Cooler]

If you are making the molding yourself, then use a tongue and groove router set to add a tongue to the molding and a groove to the board.  Glue in place.  This is face grain to face grain and the trim will never part from the piece. 

I admit the sliding dovetail seems elegant, but the attachment of the dovetail with screws and glue will not be as strong as the glue only joint of the tongue and groove.  Also the tongue and groove will be faster and easier to execute.

They are available in many thicknesses.

[Philip1231]

Unless I am missing something, this will not deal with a cross grain situation. Your trim riding in the slot is long to long grain: all is good. But when you attach to the cross grain of the carcass side, all is not good. The method I described allows the side of the carcass to expand and contract independent of the trim. I don't think your method would allow that.

If you are making the molding yourself, then use a tongue and groove router set to add a tongue to the molding and a groove to the board.  Glue in place.  This is face grain to face grain and the trim will never part from the piece. 

I admit the sliding dovetail seems elegant, but the attachment of the dovetail with screws and glue will not be as strong as the glue only joint of the tongue and groove.  Also the tongue and groove will be faster and easier to execute.

They are available in many thicknesses.

[Cooler]

Unless I am missing something, this will not deal with a cross grain situation.  Your trim riding in the slot is long to long grain: all is good. But when you attach to the cross grain of the carcass side, all is not good.  The method I described allows the side of the carcass to expand and contract independent of the trim. I don't think your method would allow that.  

Yes the ends will be end grain, but the tongues will be face grain.  And that will be plenty strong enough, and stronger than the screw attachment of dovetail.

[CLETUS]

I'd just hit it with a pin nailer and call it a day.

[Philip1231]

Ha: I had considered that, but there was not enough of a challenge

I'd just hit it with a pin nailer and call it a day.

[jteneyck]

Well done.  I think that's the best solution.

John

[Philip1231]

And here is pic after glue-up and rough sanding:

[attachment=24216]

[GeeDub]

A good solution and one I use myself. On some of the larger trim that I use on my green and green pieces I will glue the front two or three inches and use a screw in slot at the rear from the inside. Same concept and a good solution for allowing for movement. The dovetail provides a good tight fit against the case and I prefer this method.

[Philip1231]

I was amazed at how tight a fit I ended up with using the dovetail key. Prior to gluing the keys onto the carcass they were held with screws and were not giving me great confidence that this would be sturdy enough. But once the DT keys were glued and screwed in place: the fit was perfect.

A good solution and when I use myself. On some of the larger trim that I use on my green and green pieces I will glue the front two or three inches and use a screw in slot at the rear from the inside. Same concept and a good solution for allowing for movement. The dovetail provides a good tight fit against the case and I prefer this method.