MDF exterior work table

[topbobster]

Hello everyone, I've managed to acquire a few 8x4 sheets of 10mm green mdf and was wondering if I could run an idea/some questions by you all:
I want to make an outdoor work table 8x4 using 3 sheets of the mdf laminated and sealed. I did some research and found this method: spreading a film of normal pva glue on all surfaces being stuck together, letting it dry, then another film and sticking them together. I tested on 3 small 8x6 inch pieces, clamped with normal woodworking clamps and it worked very well, cannot pull them apart, I sawed the edges all round and there are no gaps at all so looks promising. For the larger project I intend to vacuum bag the 3 sheets to get good contact pressure. Does anyone find fault with the above? Next is how to keep the worktop from warping, my idea of using 3 sheets was to help here - it will weigh a lot and so will need support. Would some sort of lattice underneath work with relatively simple folding legs at the ends and in the middle. Lastly the seal.......I don't want to spend a fortune on MDF primers or sealants with "MDF" in the name......Is there something that would do the job because it will be outside over the winter/summer sun. Am not going to save money on the seal just for the sake of it - if it means spending to get an all weather seal that works, then I will.
Any help would be much appreciated.
Cheers, Rob

 

[big-all]

heeelllooo and welcome topbobster

dampness /wet will get in whatever you do
moisture resistant mdf must no be wet for more than a short while otherwise it will delaminate and fail
good luck with lifting 2 sheets glued together never mind 3

 

[TheGayOwl]

As Big All says; MDF+weather=BAD!

WBP exterior ply would be better suited. It will require plenty of protection to help it withstand our beautiful weather! Still not ideal though.

Can you not shove a tarpaulin over it in winter?

 

[Jasonb]

When MR MDF gets wet it will swell by about 75% forget it for external use. Even Exterior MDF (grey core) has to be completely sealed for outside use.

J