Carbon Fiber Door

[CUBE WITH DOORS]

Hello!

I am thinking of making a series of very light-weight doors out of carbon fiber- 4' wide by 8' high, hinge mounted on one side. I am thinking of using a .04" or .06" thick composite, but I am having a hard time understanding if this will be stiff enough so that it will not bend under its own weight. Do any of you DIY'ers with more experience with Carbon Fiber have any recommendations here? Would this work for 4' x 8'? would a thicker panel be necessary?

Thank you ~

[John Kimball]

Those thicknesses would be far too thin to be rigid or stiff enough for a door application of that size. If you used a cored panel, you can have light weight, but not thin. Cored panels are stiffer by nature, and lighter. Unfortunately, for your application, you’d need a panel that is about 1/2” thick to maintain stiffness. 

[lo_0l]

52 minutes ago, CUBE WITH DOORS said:

Hello!

I am thinking of making a series of very light-weight doors out of carbon fiber- 4' wide by 8' high, hinge mounted on one side. I am thinking of using a .04" or .06" thick composite, but I am having a hard time understanding if this will be stiff enough so that it will not bend under its own weight. Do any of you DIY'ers with more experience with Carbon Fiber have any recommendations here? Would this work for 4' x 8'? would a thicker panel be necessary?

Thank you ~

Hey @CUBE WITH DOORS,

Welcome to Composites Community! It's great to have to onboard.

The best way to go about stiffening this is by making a sandwich panel and either using foam or some sort of a honeycomb core material. This is actually how panels for space vehicles are made, so I can assure you that when built properly it will be plenty stiff enough while remaining lightweight and super strong. Heck, you could probably even market them as teenager proof! 'Slammed Doors? No Problem!®' 😄

 

[CUBE WITH DOORS]

On 7/15/2023 at 3:53 PM, lo_0l said:

Hey @CUBE WITH DOORS,

Welcome to Composites Community! It's great to have to onboard.

The best way to go about stiffening this is by making a sandwich panel and either using foam or some sort of a honeycomb core material. This is actually how panels for space vehicles are made, so I can assure you that when built properly it will be plenty stiff enough while remaining lightweight and super strong. Heck, you could probably even market them as teenager proof! 'Slammed Doors? No Problem!®' 😄

 

Thanks for the response— light is all good but how thin could I make this panel?

[John Kimball]

3 hours ago, CUBE WITH DOORS said:

Thanks for the response— light is all good but how thin could I make this panel?

For something that large, you would probably be looking at something starting at 1/2" and going thicker from there. It all depends on what the actual purpose of the door is. If it's just a cover and would be closed most of the time, then thinner is ok. However, if you want it to swing like a door on your house, then thicker is better.

[CUBE WITH DOORS]

It would just be the cover of a closet, so it should have almost no stress out on it except it’s own weight. It does not need to be perfectly rigid, but just not sag under its own weight. Would 1/2” really be the minimum? I was hoping for something more in the 1/16” to 1/8” range

[John Kimball]

I think the only way to get away with that is if you have multiple latch points. At that thin, it’s just going to very twisty and not rigid in the sense of a typical door. A piano hinge be highly recommended with something thin, as this would stiffen at least one edge. 

[lo_0l]

5 hours ago, CUBE WITH DOORS said:

It would just be the cover of a closet, so it should have almost no stress out on it except it’s own weight. It does not need to be perfectly rigid, but just not sag under its own weight. Would 1/2” really be the minimum? I was hoping for something more in the 1/16” to 1/8” range

Since typically the outside is what matters, you could make a 1/2" thick door with a 1/6-1/8" lip that you want. That would retain rigidity. The latch and hinges would just be a little tricky. You could also do a 1/8" panel with ribs on the inside of the door. You might also be able to use CF stringers inside. Just some alternative thought 🙂