Question on replacement shelf construction....

osx-addict · Post by **osx-addict** » Sat Jul 16, 2011 7:17 pm

Hi all.. I've been away for a while but am now working on a project to replace a shelving unit that used to exist but was too high (blocking a heating vent), so I'm rebuilding from scratch using 3/4" birch ply I picked up in culver city (ca). So, the old unit used dado's to recess each shelf as they were fixed in height... I haven't decided if I want to do that or use rails.. I think I've got physics against me though since the width of the unit is 49.75" and I suspect I'll have sag issues to deal with if not using shelf reinforcements to prevent it. The shelves are only 8" deep..

So.. IF I go with rails dado'd into the two sides, then I've effectively got a box to put together with or without back (back is probably needed to eliminate/reduce twisting -- correct? If a back is used how thick?

If I go with dado'd shelved (non adjustable), are there any issues you can think of that might cause trouble? By the way.. The shelve will be sitting on top of a desk with a flip down work surface.. ..

Thanks for any insight.. I have some photos but can't get them off my iPad and into the forum directly.. Too bad! They'll have to come later I guess..

charlese · Post by **charlese** » Sat Jul 16, 2011 9:37 pm

osx-addict wrote:Hi all.. I've been away for a while but am now working on a project to replace a shelving unit that used to exist but was too high (blocking a heating vent), so I'm rebuilding from scratch using 3/4" birch ply I picked up in Culver city (ca). So, the old unit used dado's to recess each shelf as they were fixed in height... I haven't decided if I want to do that or use rails.. I think I've got physics against me though since the width of the unit is 49.75" and I suspect I'll have sag issues to deal with if not using shelf reinforcements to prevent it. The shelves are only 8" deep..

So.. IF I go with rails dado'd into the two sides, then I've effectively got a box to put together with or without back (back is probably needed to eliminate/reduce twisting -- correct? If a back is used how thick?

If I go with dado'd shelved (non adjustable), are there any issues you can think of that might cause trouble? By the way.. The shelve will be sitting on top of a desk with a flip down work surface.. ..

Thanks for any insight.. I have some photos but can't get them off my iPad and into the forum directly.. Too bad! They'll have to come later I guess..

Yes, use a back! Even 1/8" hardboard will be thick enough to prevent racking. If a 1/4" back is used, the nails/screws across the back of the shelves will help stiffen the shelves from sagging.

Shelf sagging is just as liable with rails as dados - only the ends will be supported. If shelves are affixed to a solid back, the shelves being only 8" deep will probably not sag unless loaded with books, or lead weights, or gold bars.

To be extra careful about sagging shelves a hardwood facing will stop that. The unit will look better also. You can even make the facing a bit wider that the shelf. (example: 3/4' thick shelf with 1" hardwood facing.)

osx-addict · Post by **osx-addict** » Sun Jul 17, 2011 1:14 am

Thanks for the reply.. I was able to fab up all of the shelves, 2 sides, top & bottom pieces -- it's just a matter of picking the method for the shelf mounting (fixed or adjustable).. I'm tempted to just make them fixed in position which should add to the overall stability of it. Below are some photos of the project to fill in the gaps..

Here's the desk that the shelf is being attached on top of:
[ATTACH]13743[/ATTACH]

Here's one of the shelves that I'm copying:
[ATTACH]13740[/ATTACH]

I used my older Dewalt 610 router to trim 3/8" from the end for a lap joint like the original shelves used -- this is the first time I've used the microfence on the router and it works great! I've owned it new since '99 but it's been in storage since.. Not anymore!
[ATTACH]13741[/ATTACH]

Here's the plywood after sizing, trimming, cutting and almost ready for assembly (still need the aforementioned shelves figured out):
[ATTACH]13742[/ATTACH]

If I fix all of the shelves by making dado's in the side rails, then I probably don't need hardwood fronts to combat sag -- correct?

Also, where's a good place to get the hard-back? I should've asked when I was at the plywood place as I suspect they probably carry it. I'll also need edgebanding for the front edges of the plywood -- whats the ins-n-outs of applying that stuff? Should it be done before or after assembly? I gather I need one of those heating things to heat the glue -- anything else? How to trim the edges?? I might have to do some more homework before I try assembly..

Thx!!

recurvearcher · Post by **recurvearcher** » Sun Jul 17, 2011 10:55 am

I would second the suggestion of Charlese and go with hardwood facing over the edge banding. The facing will add strength and can be stained to match the existing piece. It may prove difficult to find edge banding that blends as well as a stain would. For the same reason,you may want to consider using Birch or Luan ply(1/8 or 1/4) instead of the hard-back. Have fun with the project and post some pictures when your done.

osx-addict · Post by **osx-addict** » Sun Jul 17, 2011 5:40 pm

Ok.. I'll look around for some birch plywood that's 1/4".. Interestingly enough the shelves I'm copying had no back on them as you can see in the picture above.. Not sure why that was done but it was. I guess I'll have to put this project on hold until I can find a proper backing as I'll need to reduce the 8" deep shelves by the depth of the backing since the overall 8" depth is fixed to accomodate the desk it sits on top of. Also, this shelving unit will need to be attached to the wall -- I'm hoping I can just use some small inconspicuous blocks attached to studs and then screw the shelves into the blocks -- is there any better way to attach to the wall..?

Also, regarding the edge banding.. Are you suggesting that I find a decorative hardwood (birch in this case) that would not only go on the front of each shelve to help with weight/sag issues but also around the perimeter of the entire unit to eliminate the need for any edgebanding? I hadn't thought of that.. I'll have to look at the shelving we recently bought that's partially made of Oak (yes, made here in CA even!) and possibly copy the design looks... I'll keep you posted!! (with pics!)

charlese · Post by **charlese** » Sun Jul 17, 2011 8:10 pm

osx-addict wrote:Ok.. I'll look around for some birch plywood that's 1/4".. Interestingly enough the shelves I'm copying had no back on them as you can see in the picture above.. Not sure why that was done but it was. I guess I'll have to put this project on hold until I can find a proper backing as I'll need to reduce the 8" deep shelves by the depth of the backing since the overall 8" depth is fixed to accommodate the desk it sits on top of. Also, this shelving unit will need to be attached to the wall -- I'm hoping I can just use some small inconspicuous blocks attached to studs and then screw the shelves into the blocks -- is there any better way to attach to the wall..?

Also, regarding the edge banding.. Are you suggesting that I find a decorative hardwood (birch in this case) that would not only go on the front of each shelve to help with weight/sag issues but also around the perimeter of the entire unit to eliminate the need for any edge banding? I hadn't thought of that.. I'll have to look at the shelving we recently bought that's partially made of Oak (yes, made here in CA even!) and possibly copy the design looks... I'll keep you posted!! (with pics!)

Maybe I'm going overboard here, but you can dado the vertical sides of the shelf 1/4" deep to accommodate the backing. It would probably be overboard to suggest dadoing the backing 1/8" so I won't suggest that:rolleyes: .

If no dados on the back, the shelves along with the sides must be ripped to 7 3/4" and a little more for the facing - depending how much the facing is proud of the shelf edges.

Hanging - Because of where we live - yes, all tall or wall mounted furniture must be firmly attached to something. I like to use a keyhole (T slot) mounting method. This way the wall attachment is not visible, but is firm when mounted to studs or good wall anchors. Here is an example of a keyhole router bit - and metal or brass reinforcements can be found at Woodcraft or other sources. http://www.shopsmith.com/ownersite/catalog/rmcb_tslot.htm

http://www.woodcraft.com/Family/2001928/Keyhole-Hangers.aspx

osx-addict · Post by **osx-addict** » Mon Jul 18, 2011 12:22 pm

charlese wrote:Maybe I'm going overboard here, but you can dado the vertical sides of the shelf 1/4" deep to accommodate the backing. It would probably be overboard to suggest dadoing the backing 1/8" so I won't suggest that:rolleyes:.

I'm assuming that by doing
that, you would NOT see the backing sheet if looking from the sides -- correct? Also, I'm assuming I'd still need to remove 1/4" of depth from each of the (currently) 8" shelves to accommodate having that extra 1/4" thick backing - correct?

If no dados on the back, the shelves along with the sides must be ripped to 7 3/4" and a little more for the facing - depending how much the facing is proud of the shelf edges.

When you're talking about the facing, that's either a frame system (which probably means it doesn't matter) on the entire front or if I'm using edge banding, reduce by the thickness of that in addition to the 1/4".. In this particular case, there will be shelving units on both sides effectively hiding the outsides of this unit so I could go either way but will probably try the dado method -- hopefully without screwing it up! That plywood sheet wasn't cheap at about $70..

Hanging - Because of where we live - yes, all tall or wall mounted furniture must be firmly attached to something. I like to use a keyhole (T slot) mounting method. This way the wall attachment is not visible, but is firm when mounted to studs or good wall anchors. Here is an example of a keyhole router bit - and metal or brass reinforcements can be found at Woodcraft or other sources.

Thanks for the tip.. Stupid question on this setup.. If I were to use something like this, I'm assuming it would be attached to the backside of the shelves vertical sides -- correct. If so, wouldn't the hardware cause the shelf to stick out from the wall a bit? I'm just trying to understand this method and picture it in my head.. Perhaps it's the case that the hardware mount gets recessed into the sides of the shelves?

charlese · Post by **charlese** » Mon Jul 18, 2011 3:17 pm

osx-addict wrote:I'm assuming that by doing
that, you would NOT see the backing sheet if looking from the sides -- correct? Also, I'm assuming I'd still need to remove 1/4" of depth from each of the (currently) 8" shelves to accommodate having that extra 1/4" thick backing - correct?

First, let me correct my error - I should have said 1/4" rabbets (rebates)instead of dados on the vertical sides. The answer to your question is "Yes".

When you're talking about the facing, that's either a frame system (which probably means it doesn't matter) on the entire front or if I'm using edge banding, reduce by the thickness of that in addition to the 1/4".. In this particular case, there will be shelving units on both sides effectively hiding the outsides of this unit so I could go either way but will probably try the dado method -- hopefully without screwing it up! That plywood sheet wasn't cheap at about $70.. ?

Remember even if you make 1/8" dados across the back, you will still have an extra 1/8" on the shelves.

Thanks for the tip.. Stupid question on this setup.. If I were to use something like this, I'm assuming it would be attached to the backside of the shelves vertical sides -- correct. If so, wouldn't the hardware cause the shelf to stick out from the wall a bit? I'm just trying to understand this method and picture it in my head.. Perhaps it's the case that the hardware mount gets recessed into the sides of the shelves?

If you use a "T" slot router bit, the mounting screws will fit into that slot about 3/8" or so. If you use a metal hanger for reinforcement, you should remove (mortise) enough wood so the hanger plate is inserted into the wood with its outside flush to the wood edge. Yes, I would use the vertical sides of the shelf.
The only trick in using this method is to make the wall screw height above the desk fit the hanger router slots and metal keyhole if used. A "story stick" is best used here, and easier than a measuring tape.

osx-addict · Post by **osx-addict** » Mon Jul 18, 2011 3:57 pm

Thanks! A lot to digest.. I may ask more questions once I dive into it further -- probably this weekend or Friday (my day off)..

michaeltoc · Post by **michaeltoc** » Tue Jul 19, 2011 8:10 am

Dados are great, and there are a lot of great suggestions here - but if you want adjustability, I've had good results with locking shelf clips like these:

http://ahturf.com/store/index.php?route ... ct_id=1381

If you go with either rails or clips, put one along the center of the back - that will prevent sagging.