MDF compression strength - formula/calcs???

[Digizz]

Is there a source of info on the compression strength of MDF (turned on it's side) - any rule of thum or more scientific calcs?

I'd like to see if the aquarium stand I'm proposing (separate thread) is going to be strong enough.

I guess I'll also call the manufacturers too.

Thanks,

Paul.

 

[johnelliott]

Not sure if I see what you are getting at there, Paul. I find it difficult to believe that you are asking if a piece of MDF is going to be squashed by being sandwiched between the weight of the aquarium and something rigid?
Are you going to use the mdf vertically? Perhaps you are asking if it would buckle?

John

 

[Digizz]

I want to find out if my cabinet design will withstand the weight of the tank, rock and water. It's something like a tonne in weight (still doing the calcs). The stand is a 'box', so the MDF is stood vertically like you say. I want to find out what kind of pressured the MDF will take before failing.

My other post is here:

https://www.ukworkshop.co.uk/forums/viewtopic.php?t=3885

Pictures some way down the post.

Thanks,

Paul.

 

[Anonymous]

Digizz

Don't know how you are calculating the weight of the tank but a litre of water weighs exactly 1Kg - don't know if this will help

 

[Losos]

Paul, Sorry I can't help with the MDF question but am impressed with your shop. I'm in the process of building mine (Can't pour concrete right now due to sub zero temperatures ) How much weight will your floor support? I'm also considering Sheppach but have a very heavy cast iron bandsaw to fit in.

 

[Digizz]

Paul, Sorry I can't help with the MDF question but am impressed with your shop. I'm in the process of building mine (Can't pour concrete right now due to sub zero temperatures ) How much weight will your floor support? I'm also considering Sheppach but have a very heavy cast iron bandsaw to fit in.

TBH I don't know what weight the floor will support but as it's built on 200-300 mm of hardcore/scalpings and at least 100mm of concrete, it should (hopefully!!!) support a fair bit. The floor to the cabin is spread across the concrete using double the number of joists that are normally used in a log cabin - fairly robust

The Scheppach P/T is the heavy one - especially as it has a small footprint. If I was doing it again, I'd use a hardwood floor - softwood T+G marks really easily. The plastic wheels on the bases dig in and mark the floor a fair bit.

 

[Digizz]

Digizz

Don't know how you are calculating the weight of the tank but a litre of water weighs exactly 1Kg - don't know if this will help

Thanks - that's helpfull - was just looking for that!

 

[colinc]

The compressive strength of the material is relevant to the ability of an edge to transfer the load bearing on it, but does not help you design the box carrying the aquarium. As someone said earlier the box will buckle, and well before you crush the material.

You are interested in the material's modulus of elasticity (E) to do the analysis. Mdf is not a lot better than balsa wood in this respect as it's ok in compression but poor in tension. See here for some interesting data:
http://www.geoffswoodwork.co.uk/book%20weights.htm

Isn't there something available commercially that would give you a reliable starting point? I can't help but think that I'd go for a steel frame clad in veneered mdf (but then I have a MIG welder). There are some knock together systems for box-sections that might help here.

 

[jasonB]

From my Medite details the modulus of elasticity for 18mm standard MDF is 3800N/mm2 if you can calculate it from this then good luck.

Also Medite do NOT recommend joining MDF with mitre joints where moisture is likely( such as when using exterior grade outside) , back to the drawing board.

Jason