Replies

1. 
   DonStephan | Sep 07, 2005 07:49pm | #1

   Haven't too often had permanent shelves, but I've built more melamine cabinets than I care to admit. A full width dado certainly will work, but biscuits offer a lot of strength and perhaps a tighter "joint" between shelf and side.

   I've always used a 1/2" or 3/4" solid back, for carcase strength and for looks. But 3/4" x 4" or so cleats should work if shimmed behind. The 3/4" core is not as strong as plywood, but it's pretty tough.

2. 
   TimNott | Sep 07, 2005 08:53pm | #2

   I recently did a load of melamine bookcases and wardrobes - I used a combination of biscuits and confirmats for the fixed shelves and carcase, and 5mm holes @32mm c/s for the moveable shelf supports. It worked well. Marking the holes out by hand is a pita - there's a cute gadget called Gizmo 32 from http://www.allenfield.com to help with that.

1. 
   Ecbntmkr | Sep 14, 2005 03:26pm | #3

   Don and Tim,
   Thank you both for your replies. I appreciate the input, now to put it into practice.
   Eric"When it comes time to die, make sure all you have to do is die." -Jim Elliot

3. 
   Walker1 | Sep 14, 2005 06:56pm | #4

      You can't use biscuits for fixed shelves when building with melamine board, unless you dado, and if you do that, then you don't need the biscuits.

       I wouldn't put in any permanent shelves. Dadoing melamine isn't fun, and the edges end up looking nasty unless you have a very high quality dado blade. A router will also work, but melamine is hard on the bit.

       Just screw the top and bottom plates on with particle board cabinet screws, with appropriate sized shoulder, and predrilled holes. Unless you don't want top screws to show. In that case, cut a rabbet on each side of the top plate, just enough to remove the melamine, and dowel and glue it together.

        And yes, definitely put a back on it, this will prevent any racking. And mount the back with a lot of very small screws,predrill of course, or use crown staples, to give you holding power.

                            Cheers.                             Walker1

   
   

   ---

   Edited 9/14/2005 12:25 pm ET by Walker1

1. 
   sapwood | Sep 16, 2005 04:31am | #6

   You wrote: "You can't use biscuits for fixed shelves when building with melamine board, unless you dado, and if you do that, then you don't need the biscuits."Why can't biscuits be used without a dado? I've never heard this before.

1. 
   Walker1 | Sep 16, 2005 05:44am | #7

     sapwood;     (Can't use biscuits) was a poor choice of words. I should have said, (I wouldn't).

       In my opinion,(and everyone is entitled to one). Putting fixed shelves in a cabinet like he described would probably be, (One) to add strength to the cab., and (two) the shelves are likely to be subject to considerable weight load, otherwise why bother making them fixed.

       If this were the case I would not rely on a joint that depended on biscuits, and Roo Glue to hold the end of a 3/4in.thick particle board shelf to a melamine carcass, when again this shelf will probably be weight bearing. And if the cab is subject to racking at all from being moved, or stressed during installation, or being removed and being reinstalled in a different spot at a later date, how long do you think that 3/4's of an in. of particle board will hold on to that melamine.

        Like I said at the beginning of this post, this would not be my method of joint construction.

           Roo glue is recommended for adhering melamine to particle board, but I would be surprised if the manufacturer would endorse it for the purpose talked about here.

                          Cheers.                            Walker1

   Edited 9/15/2005 10:52 pm ET by Walker1

1. 
   Segil | Sep 16, 2005 02:53pm | #8

   Walker1,

       I certainly agree with you that a dado joint dramatically increases the shear strength of a fixed shelf joint.  I actually did display shelves for a metal casting company and you better believe I dadoed in the shelves.  Biscuits are more of a medium duty joint, such as most residential applications.  The biscuits should be located about 1/8" above the bottom face of the shelf, not in the center.  This gives you effectively a 1/2" of material sitting on the biscuits.  It would take an abnormally heavy load to make this joint fail.

        For maximum strength, I stop-dado the sides and screw through.  This is the best way to resist the racking you mentioned, as a glued dado alone will not resist racking effectively.  I laminate the outside surface of the sides to cover the screww heads.  I reserve this construction method for commercial applications.

         One more comment-  There is another purpose for fixed shelves.   In a large shelving installation,  alignment of the shelves may need to be preserved for aesthetic reasons, even at the expense of efficient storage.  Some people also hate the look of shelf pin holes. 

1. 
   Ecbntmkr | Sep 16, 2005 03:56pm | #9

   Thanks for everyones added input. Just to clarify. The cabinet is 60" high by 10" deep by 32"wide. It will be mounted on the wall 24" above the floor in a residence. The three permanent shelves that I refer to are the top and the bottom and one in the middle. The middle shelf will be centered in the middle of the cabinet. The reason for this is the door size. I wanted to get to door sizes that were not much bigger than 30" high rather than doors that are 60" high. The permanent shelf is simply to "break" the cabinet up.
   The bottom shelf will be flush to the bottom of the sides, so a dado joint there would actually be a rabbet and I'm not sure that the shear strength would be enough there. Screwing would be the easy way to go, but there is to be no visible fasteners.
   Thanks again for everyones advice.
   Eric"When it comes time to die, make sure all you have to do is die." -Jim ElliotEdited 9/16/2005 9:09 am ET by Ecbntmkr

   Edited 9/16/2005 9:09 am ET by Ecbntmkr

2. 
   Walker1 | Sep 16, 2005 09:32pm | #10

     Seguil;   I don't doubt your expertise in this matter for a second, and I appreciated the advice you gave me on choosing a stationary sander.

       Having said that, I want to clarify that my response to the original post was advice on how to keep it simple, with little risk of joint failure,thats why I advised, no fixed shelves. The poster already said he's putting in adjustable shelves, so I would guess that shelf pin holes dont bother him . He also says that he has little experience with melamine, and may,or may not have seen how easily joints can fail, and crumble. It was not intended to debate methods used by more experienced builders. That can be confusing.

       For instance, in your second post you explain biscuit placement, which I already knew, but we don't know that he knows that, and you didn't mention that when recommending glue.

       The poster goes on to explain that he,s not certain of his joint strength in the corners of the carcass, which was my concern as well with reguard to racking.

         My original response was straight foward, and simple advice on how I thought he should handle this project. I wasn't attempting to answer anything other than that. He can use the advice, or disrequard it, It's his choice.

        The fact that this discussion seems to have taken on an unpleasent tone, is my fault, and I apologize. I made the mistake of responding to sapwoods post, which was obviously meant to be more argumentative in nature, than a legitimate question.

       I've noticed some people seem to sit there reading every post carefully, waiting to pounce on anything they perceive to be incorrect, instead of putting there effort into giving helpfull responses where they can.

                            Cheers.                             Walker1

3. 
   Segil | Sep 16, 2005 10:26pm | #11

   Walker1,

        I don't disagree with anything you said in your last post, and no offense was taken.  Please don't feel you were out of line,  we're all on the same team having a spirited discussion. 

        Good luck with the new sander!

4. 
   Segil | Sep 15, 2005 02:16am | #5

   There is a product called Roo Glue which is formulated especially for gluing melamine to particle board, and it works great!  I use it to do fixed shelves along with biscuits and yellow glue to avoid dadoing.  The yellow glue goes into the biscuit slots, and the Roo glue goes on the end of the shelf where it will meet the melamine.  The excess wipes off easily with water.  I think Rockler and Woodcraft Supply carry it.  I never do melamine without it.