Thread: MDF m&t ?

Another def. IMHO = In my Humble Opinion.


Cheers..................Sean

Originally Posted by savage

In My Honest Opinion

You sure it's not In My Humble Opinion?

Ooops. Just seen the last post. I'm with scooter on the acronym thing.

Thanks Eric.

Peter

Thanks for your interest/advice.

Been doing a few other projects, which have lead me off the Mdf track the last few weeks.

After my last post here, I glued up two mdf tenons into radiata 40x40(leg) with titebond II and have tried every few days to pull/bust them apart using my hands, with no success...My foot or a vice should work. But in service I can't see that type of force accuring.

Hopefuly tomorrow I will rig up some kind of leverage to break it apart, because I'm curious lol to see what location gives first.

Mind you all that leverage will be overkill, for the intended purpose of the finished piece.

Heres all the parts cut except the legs and mdf shelves, will know soon if radiata legs will be ok.

Attachment 24364

Attachment 24365

I will post the broke joint asap.

Looking good after plenty of hand force.

Attachment 24368

I could crush them both together, but that would be unfair test and nothing like the forces it will have once mdf shelf is installed.




HJ0 May the force be with me lol

Heres what happened.

First mdf tenon test, using a 900mm long 40x40 length of radiata as the weapon.

Wouldn't call it a shear test, but it was more about where it would break. Pulling downwards on the tenon at the end of 900mm of pine... with approx 1/3 of my strength.

One loud snap/pop and joint is buggered, but it was a surprise to see the tenon pull out like it did.

(1st tenon test)

1 - Before
Attachment 24413

2 - Clamps needed adjustment, so I could obtain enough force.
Attachment 24414

3 - Clamp arrangement used
Attachment 24415

4 - Tenon after forces applied
Attachment 24416

5 - slippage during test
Attachment 24417




HJ0

Second tenon test was twisting the tenon, using approx 1/8 my strength with the same weapon as the 1st test. Sounded was more like ripping a notepad in half.

In service I couldn't see a tenon receiving this kind of treatment.

06 - Clamp arrangement
Attachment 24487

07 - Broken joint
Attachment 24488

08 - Close-up of broken joint
Attachment 24489

09 - Close-up of both broken joints
Attachment 24491

10 - Weapon used in both tests
Attachment 24490



After testing mdf tenons , I will no doubt be using them in the future without fear....But only on projects that are cube like ie trolley's/tables etc 0r where the intended use does not have an internal combustion motor fitted lol.

I would not advocate using mdf tenons in chairs(more like benches), unless all tenons are of a decent size(no 10x10mm lol) and depth(no 10mm).... and I would make sure all mdf tenons are glued into solid timber only.


HJ0 When I complete my mdf project pics will follow