On no! The holes too big!

[Souzag818]

Originally Posted by Stumble

FWIW I would recommend against starboard. In this application it will probably work, but over time it will start to sag and flex. It really doesn't have any structural strength and between the heat from the sun and its thermal expansion it will eventually break seals. I would recommend going with a thin non-strutrural fiberglass board. Its pretty cheap and will last a lot longer.

I agree. McMaster Carr sells f/g sheets of different sizes and thicknesses that would work way better than starboard. Just search fiberglass sheets at their web site.

[Stumble]

Originally Posted by travellerw

Hmmm I have tons of things made from starboard that has not exibited the problem you describe. I've NEVER had any sagging or seen any "thermal expansion", even down here in the Caribbean (in direct sunlight). 2 years on and it looks exactly like the day I made it. Even though the gelcoat around has chalked up a bit.

Down here, its the "go to product". I have literally seen 10s-100s of items made with Starboard that have been on boats for 3-5-8-10 years. Almost all of them look like they were made yesterday (with the exception of fish stations).

Have you made anything from Starboard? Are you sure you have been using Starboard? Maybe you have been using another brand, that is made from different plastics.

Yes I have used it quite a lot. It is fine in compression if the load is spread well but it has some real issues. First it cold flows, under fastener pressure it will flow away from clamping pressure. In fact the first suggestion on the brag sheet from King Starboard is "Store the sheets at on a level surface, as the polymer can cold flow." http://www.kingplastic.com/wp-conten...-StarBoard.pdf

Second it moves a lot with temperature so much so that if you are ordering it from a high end shop they should ask you what the service temperature will be so they can drill it to the right size at that temperature. For fasteners that are a nominal 36 inches apart and will experience a temperature swing of 70 degrees (30F at night in the winter to 100F during the day in the summer) the total expansion is 70*.00006*36=.15 (about 3/16 inch) inches. It doesn't sound like much, but it is enough to cause the bolts to wallow out the holes over time.

Its a fine material for what it is, but when asked to do things it doesn't do well it can end up forcing you to redo the job down the road.