Fabricating outdrive wear pads - what material to use

[wca_tim]

I need to make wear pads for a couple of things that aren't available anymore (alpha ss drive and land and sea sternjack), does anyone know what material these are generally made of?

I'm sure I can find a supplier for the materials, but would hate to have to do the homework to figure out what type of material to use. Any input greatly appreciated.

Thanks!

Tim

 

[Gimme Fuel]

Are they the plastic wear pads?

 

[wca_tim]

Yes! You can see them on the side of the drive. The ones for the sternjack are a different shape, but I'm assuming the same material will be fine.

 

[wca_tim]

Here's a closer one....

 

[Gimme Fuel]

I would say something like a UHMV or Teflon like material would work great......HDPE would work too......basically you just want a hard, dense plastic. ABS I think would be too brittle.

 

[mkhammer]

it's called a "polyethylene high molecular weight plastic" ( it's like cutting board plastic)

It's the same stuff the pads are made of, I have made a couple differerent wear pads out of it.


You should be able to buy it at a plastic supply Co. or I can mail you a piece I have some 1/2"

MK

 

[Gimme Fuel]

Ok....so it is HDPE then (High Density Poly-ethylene)

 

[Mr. Buss]

Ok....so it is HDPE then (High Density Poly-ethylene)

yeah, what he said...

Hey Gimmie, That sounds like the same stuff your skull is made of...high density....haha

 

[yellowfiero88]

yeah, what he said...

Hey Gimmie, That sounds like the same stuff your skull is made of...high density....haha

 

[wca_tim]

Thanks fellas!

I wasn't sure what it would be, but now that I know, I can come up with some... of all the things, i'm a polymer chemist... (plastics chemist...), I could have taken some guesses, but you saved me a bunch of time...


MK, thanks a ton for the offer! I need a couple different thicknesses and will order some.


now the next question is.. blower or no, and which kit...

 

[mkhammer]

Hey I didn't make that name up that's what the dude at the plastic store said it was called.
When he first told me the name of it I said what? I buy it from S&W plastics.
If anybody's skull is made out of that stuff you don't need a helmet.

MK

 

[yellowfiero88]

Tim, when I worked at a conveyor shop, we used the same material for slides, etc. neat stuff and machined real nice.

 

[wca_tim]

Hey I didn't make that name up that's what the dude at the plastic store said it was called.
When he first told me the name of it I said what? I buy it from S&W plastics.
If anybody's skull is made out of that stuff you don't need a helmet.

MK

and Mr. Chemistry says....

Molecular weight refers to the length of the molecules. cheaper versions of polyethylene have relatively short molecules. You can think of plastics (polymers) like long chains or ropes all knotted together like that furball of fishing line and rigs in your tackle box got before you finally just threw it away. so if the chains are short, they pull apart pretty easily and the plastic isn't very strong, if they're long then it takes a lot more to untangle them and the material is much stronger.

The next part is orientation / alignment. if you have really long chains and just wad them up, versus having them all aligned stright next to one another, there is less air / void space between them and so there are more chains in a given cross sectional area. for polyetheylene, the simplest plastic there is, if it is highly oriented high molecular weight it is as strong or stronger than kevlar - "gel-spun polyethylene" is sold for example under the name Dyneema by DSM chemical and is used in the manufacture of bullet proof vests.