Picnic Table #2: Building the Form

In keeping with my pledge to only use leftover and recycled material, I decided not to buy the construction plywood to make the form but to use some saved MDF IKEA closet from the days I had the apartment. That decision will prove to be costly…

The panel are 24" wide and 93" log so I will have to add to the width to at least 26" since I have a 26" radius.
Ideally I need 52" for a full form (diameter=26×2).
It became quickly apparent that this will be heavy to move and cumbersome to cut on my bandsaw.
So I decided to make 2 half arcs and glue them after the radius is cut on the bandsaw.



Cleaned up the MDF top laminate so I can glue the other pieces on it.

The base MDF is 3/4" thick so I added the first layer of 2×6 (leftover redwood from my pergola build).
I topped that layer with another layer of MDF to tie them together. Glue and screws
Yet another layer of 2×6 pieces.
The thickness of the form ended up being: 3/4 + 1 1/2 + 3/4 +1 1/2 minus all the planing it took to get the 2×6 flat for a total of 4"

One more trip to the bandsaw and the circle cutting jig, I got my final form shaped.
Pictured here with some trial laminates.

Now I had to deviate from the forum post to accommodate material I had on hand. Not pretty but somewhat functional.

Problem:
I ruined 2 belts in doing that.
The first one snapped half way though sanding the last piece of MDF to remove the plastic covering the laminate with since glue does not stick to it.
It looks like it was not close to being flat. The breaker tripped and the belt was gone. The drum scratched.

In my haste in changing the belt so I can continue working I cut the replacement belt from a roll about 1" too short…
I think 2 sheets of construction plywood would have been much cheaper(:-

With the form build I moved onto the laminates.

Tags: bending

Abbas, Castro Valley, CA

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4 Comments

Madts ...

Isn’t fun trying something new. Well at least you got a good start on that beast.

Bentlyj ...

Looks like you’re having fun and all is going well.
Did you notice any spring back when you took your pcs off the form?
I usually will cut my form in about a 1/2" to 3/4" more on each side so that when I get spring back it springs into the position I originally was after. Another thing that helps with spring back is to use powdered urea glue. It doesn’t have the creep like titebond does and will hold the curve tighter. For what you’re making it isn’t critical though, so venture on and keep us posted on your progress.
Nice job on your forms using leftover and recycled material.

lanwater ...

It is certainly fun Madts. Frustrating at time but fun overall. Thank!

Bently, I am very surprised about the spring back. More like spring inward :)
The first one had a very slight spring back.
The second I had to put some effort to get it out of the form.
I was reading Urea glue is toxic so I am scare of it.
I was thinking about epoxy but that thing is expensive. So I thought I try with titebond 3. I am not expecting that table to hold more than a year or two

Mike40 ...

Great work on the forms Ian. I’ve always wanted to try some bent lamination, but just haven’t found a suitable project yet, or maybe it’s just laziness. I still think that table is going to last a whole lot longer than you think it will.