Another alcove shelves post...

[Christopher Souza]

I have got to make 4 alcove shelves in the next month or so. She wants them to be oak to match the oak alcove units I made below.

1232mm long, 300mm wide. They need to be about 40mm no thicker, maybe slightly less at 35mm. They might hold a bit of weight with some books etc, but probably mostly ornaments and some pictures. I am thinking of using MDF to make the shelves, then veneer the top and bottom with oak veneer, and use a 12-20mm oak edging for the front.

I can attatch battens to the walls and at the back to support (the shelves can be slid onto them) which I think makes most sense. Of course to make life easy my 1880 house has walls curved like bananas.

I have never glued on veneer sheets before, I know a veneer press or vaccum press is the ideal thing to use, but I will probably have to use just some sheets of ply to press them (I might be able to use one of our 'vaccum storage bags' - the things for clothes, not sure if that's a good idea or not!

I'm interested in advice on the shelf construction. It should be well supported at the sides and back with the battens as described, I was going to make them with 9 or 12mm MDF, hollow with some brace pieces to space the two sheets out to get the right total thickness. Would the hardwood edging at the front be sufficient for structural rigidity or would it be worth trying to embed something more rigid in the construction somewhere.

I'm on a budget approach to them.

Thanks in advance for any wisdom or expertise anyone can share.

I can't imagine just using oak plywood isn't a more cost effective solution over MDF. MDF will bow, it's nowhere as rigid or strong. Adding veneer does very little for strength. Plus the cost and time to apply it.... I'm not seeing the advantage from any prospective. Add a piece of nosing to each shelf, equal to 1.25X the shelf material thickness. So if it's a 1" thick shelf, your nosing is 1-1/4". I just glue and pocket screw mine, but I've seen others add a spline or even a few biscuits. Which again does very little for strength but it does add more glue surface. I think if you do as recommended you'd be able to populate the shelves with books, no problem. You've got to cut the shelves anyway why not preform your own experiment? Test it out!

 

[Spectric]

I can't imagine just using oak plywood isn't a more cost effective solution over MDF. MDF will bow, it's nowhere as rigid or strong.

But it is cheap and readily available even though it makes horrendous dust when cutting.

 

[Christopher Souza]

But it is cheap and readily available even though it makes horrendous dust when cutting.

I'm in the US, Boston area and there's only $40 difference between 3/4" thick MDF and red oak plywood in the same thickness. So for me adding all the veneer is not cost effective, between labor and materials. Edge band alone would add more in material alone to make that route more expensive.
Okay so we've resolved you're using MDF period! I'd definitely add nosing and maybe also a strip on the back of the shelf too. Either underside or on top of the shelf(ves) for rigidity.

 

[Christopher Souza]

But it is cheap and readily available even though it makes horrendous dust when cutting.

 

[Spectric]

Yes for us we always seem to have to pay way over the odds for decent materials, that works out at about £70 and for us an 18mm sheet of MRMDF is about £50 and for ply is about £130 for decent grade Birch with hardwood being £170 but you have to shop around as the prices seem to vary with the weather !