Since I found just really expensive Urethane front lips (over 500$) I thought of trying my own. Yesterday I made the first part of the frame I’m going to use for a Prototype mold.

Sorry for the bad quality.

My idea is to use this to create the molding sample and then use just a top metal inlay to make it rigid when I’m going to pour the Urethane in the mold.

The Urethane I’m going to use will be a Shore A75.

Does someone have experience and inputs on what I have to look at ? What Problems could I have?

 

Thanks in advance

Marcel

Nice!

 

I suspect bubbles in your mixture or keeping it the same thickness would be the biggest issues. I suspect most of the parts are injection molded or made in a vacuum chamber. Which is why the cost is so high...

Thanks for the inputs.

I think with the the sturdy alu construction the thickness should be given. The urethane mixing and pooring id also my biggest concern. Is there a "best way" to do it?

I finished the frame, now i have to cover it with rubber mats(4mm thick layers) and construct the box for the mold.

You can build your own vacuum chamber out of plywood (and lots of sealant).

And what kind of vacuumpump is needed?

Edited October 5, 20179 yr by munters

For thin film I figure somewhere between 8-17 inches of Hg (mercury). A 1.75 hp vacuum pump usually can reach 26"Hg.

I suggest you research the use of sand in a vac chamber. You can also build one out of plexiglass but I have seen them made of plywood with a plexiglass top or window so you can see what's happening. The weight of the sand keeps the barrier shield film mostly uniform over the material you want to layer over the part.

To me it seems that you would need to build up several layers to get to the thickness you're hoping for.

You can also research carbon fiber vac methods

Edited October 5, 20179 yr by gnosez

Ok thanks I will google a bit.

The Prototype is done the only thing I have to do ist sand down again a bit of the structure you can sort of see in the pics.(Sorry smartphone pics... I have to take a camera to make better pics)

The last one is upside down. The measurements are close to the Original Urethan lip. 2cm on the top and 1cm on the bottom.

In the final Urethan version I will change the Alu frame. It will have a top and middle bar to be able to change the angle (by bending) of the Lip if I want to.

The bottom bar will not be there

Next step is building the woodbox to create the mold.

It takes time, but it goes somewhere.

The endresult with a camera.

Any pictures of this fitted? It looks fantastic!

I was not clear in the last post

This is the Prototype to use for the mold not Urethane yet.

Im now building a box and then the endversion in Urethane with suporting brackets inside.(to adjust the angle the way i want it and give rigidity)