G10 Composit - Application requires part to remain ridgid

[7SEAS777]

Researching G10 composite for marine use. The part will be around 10" in length,1" thick and 4" wide. Foil shape for marine application and needs to stay rigid under pressure.

 

[Transient1]

Please specify the loading conditions better.

Is it in tension or compression?

Will it be twisted?

Will it be exposed to repeated cylic loading?

How will it be fastened to whatever you are fastening it to?

Why G10 instead of a corrosion resistant stainless? (Is weight an issue, cost?)

 

[7SEAS777]

Thanks very much for your response,

Compression

There is the potential to twist. I'm hoping the G10 will eliminate this possibility.

It will be exposed to repeat loading. The weight of the loading will vary from moment to moment due to marine operating conditions.

It will be removable. The section that holds it in place will penetrate 1" into the hull and will be 1/2" wide and 4" long. This insert is about half the width of the part under compression. In the past the reduction from 1" to 1/2" has held without exception all loads/compression placed on the part.

An advantage of G10 over SS is that it can be easily re-shaped/refined. Stainless would be too heavy and expensive for this application.

In your experience who is the best G10 manufacturer in price and service?

Many thanks,

Edward Spencer

 

[Transient1]

Edward,

I work primarily with G10 in the circuit board industry. Unfortunately, our purchasing department handles procurement so I couldn't tell you who is good and who is not. Although, I've been told when we get the circuit boards made, our subcontractor will subcontract out to different companies for the laminate. So I would tend to get the impression there a good number of suppliers out there. Sorry I can't me more help there.

You mentioned that without expection this part has not failed, so the G10 part has been in service all ready?

Has analysis on this part been completed previously or is that something your now trying to tackle?

-Chris

 

[MikeHalloran]

G10 is an frp composite, normally supplied in sheet form to the electronic circuit board industry. Its properties are optimized for electronic service, not for marine service.

Okay, you _can_ get it in thick sheets, and you _can_ shape it to look like a surfboard skeg if you want. But milling leaves you with a rough surface, with the fractured ends of glass fibers exposed, so you have to seal the surface. And the fibers are not then aligned for optimum strength.

You could instead vacuum bag a layup over a foam or wood core, and end up with the fibers aligned for better strength, better stiffness, and less weight.



Mike Halloran
Pembroke Pines, FL, USA

 

[PanelGuy]

I would look at Norplex Micarta. They probably have the broadest offering of way more than G-10, plus they have the most knowledge to back it up. McMaster has a ton of smaller plates of the varieties if you just want to test the garolite brand.

I would echo Mr. Halloran in that you will need probably need to seal and sand edges, but it depends on the substrates.

The worst issue may be that when axially loaded the laminate may split. I have seen this dealt with by changing the angle of machine...ie. a symetric airfoil could be machined with the material at a 10 degree angle to ensure all axial shear is shearing plies not layers.

However, if this is an "ablative" control surface perhaps long term lifecycle is not an issue.

As well, a bladder formed or cored composite structure may be good. However, if you are looking to test several different shapes at once the machinability of G-10 would make it lead in a prototype.

Darin