From: dbailey@bcarh673.bnr.ca (Douglas Bailey)
Subject: Re: Help with making stand for 2 55g tanks
Reply-To: dbailey@bcarh673.bnr.ca (Douglas Bailey)
Organization: Bell-Northern Research Ltd.
Distribution: na
Date: Fri, 14 Aug 1992 18:25:23 GMT


I'm an amature wood worker.  I've built 3 different aquarium
stands (one for a 70 gallon tank & 2 different ones for 33
gallon tanks).  I'm currently contemplating two stands to
hold 4 25 gallon tanks in configurations similar to that
wanted by the original poster.

Here's my dissertation on the subject.

For any joint which is expected to support a great deal of
sheer force, you're best off ensuring that there is some
structural member supporting those that will support the
weight.

For example, a bad choice would be a butt joint:

                   | force
         ____      V
        |\   \
        | \___\---------------
        | |   |               \
        | |   |----------------
        | |   |               |
        | |   |----------------
        \ |   |
         \|___|

In a butt joint, the only support against the sheering force
of the weight of the tank would be whatever mechanism is used 
to hold the two pieces of wood together.  The original poster
stated that he would use screws.  Screws are ok, but will tend
to loosen if the stand gets moved around or bumped.  In softwood,
the screw holes will deform under the weight of the aquarium and
accellerate the loosening process. My general philosophy is to
have the wood support all of the weight.  Whatever glues and
screws you use are there only to keep the various pieces in
the configuration which supports the weight most effectively.

The best bet for something like this would be to cut a notch in
the verticle member into which the horizontal member fits.  Then
the downward force of the aquarium would be transfered effectively
to the verticle member without depending on the connecting 
mechanism.

For example:

     |\----\
     | \    \                  |  weight of tank
     |  \    \                 V
     |   \    \
     |    \----\           ______________________
     |  \  |    |         |\                     \
     |  |\ |    |         | \                     \
     |  | \|----|         |  \_____________________\
     |  |    |            |  |                     |
     |  |    |      <---  |  |                     |
     |  |    |            \  |                     |
     |  \----\             \ |                     |
     \   \XXXX\             \|_____________________| 
      \   \XXXX\         
       \   |----|
        \  |    |       horizontal member fits into notch in
         \ |    |       verticle member.  Weight of tank is
          \|----|       transferred to surface marked 'X'.


For a 55 gallon tank, using 2x4s for all members, I'd place the
horizontal members on edge (so their cross section is 4" high by
2" wide).  The verticle members should show their narrow edge to
the front and back of the stand.  Then, in each verticle member,
cut a notch 4" high by 2" deep to accept the horizontal members.
For work like this, the notch can be effectively cut with a
hand saw and a chisel.  If you've got access to a table saw or
radial-arm saw, all the better.

I believe a 55 gallon tank is 4' long.  For any stand 4' or greater
in length, you should really use 6 verticle members.  One in each 
corner, plus one in the center of each 4' horizontal member.

I hope my ascii pictures and explanations were clear enough.  If 
wish to ask me any further questions, post them.  I can't receive
email here.

Doug Bailey