DIY straight edge with Epoxy+ aluminum profile. Will it work?

[ba99297]

Hi
I want to describe an idea that I had last days.
As it is very possible to use epoxy level for my machine and I will use a small amount of epoxy ( that will finally go to thrash) for some tests. So I was thinking if it reasonable to make the tests using two aluminum rectangular tubes 80X20 as follows.
We start with a 6 m long aluminum rectangular tube, cut into two pieces of 3m long each




We attach the two tubes with 2mm spacers( blue color)




At the edges we put two pieces of mdf as at the following pictures also with spacers between the mdf and aluminum profiles
We put the spacers so that we can cut the epoxy after cure.
Then we level the tubes, we fill with silicone the 2mm gap that the spacers will make and we pure epoxy.



After the epoxy get hard, we remove the spacers and we use a hacksaw blade to cut the epoxy

We now have (or we don’t have ????)two pieces of aluminum profile with a true surface.



MDF offsets are used to “absorb” the meniscus



We will need nearly 0.5*6.6*300=990ml of epoxy ( for this length )
1 X6m long aluminum rectangular tube
Spacers
Mdf strips
Of course somebody could use shorter tubes, even one only tube with mdf stripes left and right or cut the tube (after epoxy cure) to different lengths.

What is your opinion?
Does it worth to try?


I edit the post to make it more clear, ( after i read clives_s question that follows).
The main purpose of this DIY is to make a straight edge with low cost, instead of buying one that at this length will be out of the question.
The aluminum tubes that will be produced from the above process WONT be used as adjustable top beams where the rails will rest