Materials - Graphite powder & epoxy vs solid

Apologies if this is a bit off the forum topic.
But didn't see one that covered materials

I'm looking to cast a solid custom rigging parts, like dead-eyes


If I use a mix of graphite powder or aluminum powder and epoxy in a mold would I attain the same or close to the same tensile/compression strength as solid aluminum?

 

No, not even close. The compression will be lower and the tension is way lower.

 

How about with milled carbon? or ceramics?

 

You could use aramid or carbon fiber, but the dimensions will have to be different. It will have to be engineered for the material.

 

Listen to Gonzo.

You need long fibers, not short fibers (milled) or powder.

You also need to forget about threads in a Gr epoxy laminate - unless you really don't need actual strength.

If you ever try making a fitting like a deadeye, set up a test that will load it 2 - 3 x the load you need. Actually 5x would be better if you don't know about how structure and repeated loads act.

There are guys who have made chain plate attachments by wrapping uni-directional graphite around a wire eye and spreading out the fibers on the side of the boat. Again, test it well before trying to use such a thing.

In this case, metal good.

 

It's a deadeye folks, they were used to do them out of wood thou not softwood but not ebony either. Don't overcomlicate IMHO it's just there to prevent chafe and allow even loading..

 

I've cast epoxy parts with good success, but you do need to have a clue about what you're trying to do. I agree it doesn't have to be over engineered, but deadeyes are pretty highly loaded sometimes. The old wooden ones have been known to explode and personally, I can't offer any good reason for them, unless interested in the lightest weight, lanyard and lashing style of rig.

What other parts are you going to cast and how highly loaded is the rig, they'll be hung on? If it's a low aspect gaffer, just use a heavy concentration of milled fibers, silica to control viscosity and the powder of the color you want. Pigment would be a better choice, as the resulting milled fibers and resin mix, will be stronger than with any powder. If it's a highly strung rig, you'll want to work out the loads, so you can make up a reasonable laminate schedule, which will likely include fabrics too.