StarBoard vs Marine Plywood ?

[AquatiCat]

Good choice for anything that does NOT require anything to be glued to it. Starboard is great but doe not hold or take glues well.

[Charlie]

To clarify my earlier post the starboard will hold the shape until heated again. Then you can bend it back

[twistedtree]

Originally Posted by Charlie

To clarify my earlier post the starboard will hold the shape until heated again. Then you can bend it back

Oh, now I understand. Thanks for clarifying. I might take advantage of that.

[GordMay]

Originally Posted by s/v Jedi

Well I learned something: I never expected it to be as stiff as plywood !

It's not.

Nonetheless, Twistedtree has done a nice job, and appears to have provided adequate support for his application.

From King StarBoard FAQ’s: ➥ FAQ | King Plastic Corporation

Q. Is King StarBoard as strong as marine plywood?
A. There are many types of marine plywood. The better ones are stronger than King StarBoard, which was not designed to be a structural material.

For comparison:

King Starboard Physical Properties
➥ http://www.kingplastic.com/wp-conten...Properties.pdf

Mechanical Properties of Wood
➥ http://www.woodweb.com/Resources/woo...dbook/Ch04.pdf

[twistedtree]

Originally Posted by GordMay

It's not.

......

Q. Is King StarBoard as strong as marine plywood?
A. There are many types of marine plywood. The better ones are stronger than King StarBoard, which was not designed to be a structural material.

For comparison:

King Starboard Physical Properties
➥ http://www.kingplastic.com/wp-conten...Properties.pdf

Mechanical Properties of Wood
➥ http://www.woodweb.com/Resources/woo...dbook/Ch04.pdf

For an application like mine - floor material across a span - which numbers do I compare between these specs? There are so many aspects to "strength" like, sheer, compressing, nail and screw holding properties, twisting, etc. In construction, I've seen specs for floor loading based on the decking material and joist size and spacing. I tried unsuccessfully to find useful quantitative comparisons for materials, so I resorted to subjective testing with plywood and Starboard, same thickness, same support spanning, and my fat ass sitting on top of it. The grade of plywood I was using was "the sheet in the garage" grade. I was both trying to understand how much starboard deflected when weighted down compared to plywood, and sort out which thickness of starboard to use.

In all honesty, I had already decided to use starboard (or some similar brand) provided it would adequately support weight in my application. The driving factors were partly rot resistance, but much more not having to go through the process of sanding, sealing, priming, painting, etc. which I hate with a passion. The whole thing cost me under $300 which was worth every penny considering I didn't have to do any finishing work.

Not all applications are the same and it's certainly not the right material for many things. And everyone places different values on different things. Some people love sanding painting and finishing things - just not me. For me, in this application, it worked out great.

But I'd still love to know how to quantitatively compare these materials....

[kthoennes]

That job looks very hood, thanks for the photos. Funny this topic should be bouncing around right now. Part of our slip at the marina is covered by a composite decking. In the middle of that decking I made an inset, 18" square, flush with the deck, under a thick piece of tempered glass, to display the boat's name and crest on a white panel. I used marine plywood last summer for the panel. It's a brutal spot, 6" above the water on the bottom side, and under glass on the top side that acts like a heat concentrator. The marine ply rippled like a washboard by the end of the season. I bought a piece of starboard at the Dania boat flea market last weekend and I'll see if it's as impervious as everybody says.

Thanks again for this thread, good to know it's so strong because that deck panel is supposed to be walked on (16" span). I was thinking of lighting it from the edges too so it glows at night. I'll find out how translucent starboard might be.

[GordMay]

Originally Posted by twistedtree

For an application like mine - floor material across a span - which numbers do I compare between these specs? ...

But I'd still love to know how to quantitatively compare these materials....

Yours is an excellent question for a structural engineer, or other materials scientist (none of which am I).

I believe that your “sit on it” test approximated the bending stiffness (elastic modulus) or the flexural modulus (flexural strength), which represents the stiffness, or tendency for a material to bend.

[minaret]

How did the OP fasten the starboard to the hull? Just curious...

[twistedtree]

How did the OP fasten the starboard to the hull? Just curious...

It just sits there. Each piece is scribed and blocked in such a way that it locks into place with one part of the hull or another keeping it from sliding around. That way each piece can just be lifted out for inspection and cleaning underneath. As an example, in the picture below you can see how the support is scribed around the stringer which locks it into position side-to-side. It can't slide aft because of the rudder posts supports, and the piece forward of it prevents it from sliding forward.

Oh, one thing I haven't done yet is drill vent holes. I haven't sorted out the spacing which of course is a tradeoff between loss of stiffness and amount of ventilation. But I have a 1-1/2" hole saw ready to put to work. I figured I'd get everything arranged first, then place the holes afterwards.

[Billy Higgins]

How would 3/4" or 1" thick Starboard work in place of teak in the building of a small grate (over a fiberglass shower sump) on the floor of a shower stall - 24" x 20". Can it be routed and built on a bench jig just like a grate made from, say, 1"x 7/8" teak. With a traditional teak grate there would not normally have been glue, but screws holding it together, so I am optimistic that starboard would be similar to build. The finished grate would certainly have better sanitary properties, it wouldn't swell, and would probably be easier to clean.

[twistedtree]

Originally Posted by Billy Higgins

How would 3/4" or 1" thick Starboard work in place of teak in the building of a small grate (over a fiberglass shower sump) on the floor of a shower stall - 24" x 20". Can it be routed and built on a bench jig just like a grate made from, say, 1"x 7/8" teak. With a traditional teak grate there would not normally have been glue, but screws holding it together, so I am optimistic that starboard would be similar to build. The finished grate would certainly have better sanitary properties, it wouldn't swell, and would probably be easier to clean.

Is the grate 24x20 and supported only around the edges?

I would tend to say Yes, but I'd encourage some sort of experiment to test the strength to be sure it meets your expectations. The only thing I can't be sure of is how sturdy it will be in strips, or as a solid piece with lots of perforating holes.

Are you thinking of cutting the Starboard into strips and fastening them together? If I were doing it I think I'd try to make it from one solid piece of starboard and drill a pattern of holes to make the grate.

[Capt.Fred]

Originally Posted by Billy Higgins

How would 3/4" or 1" thick Starboard work in place of teak in the building of a small grate (over a fiberglass shower sump) on the floor of a shower stall - 24" x 20". Can it be routed and built on a bench jig just like a grate made from, say, 1"x 7/8" teak. With a traditional teak grate there would not normally have been glue, but screws holding it together, so I am optimistic that starboard would be similar to build. The finished grate would certainly have better sanitary properties, it wouldn't swell, and would probably be easier to clean.

A strong, sanitary and handsome shower grate as follows: 20" x 24" x 1" Starboard. draw parallel pencil lines spaced 1" apart east & west on one side. Turn board over, draw pencil lines spaced 1" apart north & south. On side with lines going full 24", rout every other space 3/4" deep. Turn board over, rout every other space 5/16" deep. sand edges smooth and there you are...no screws. Make your boarder by drawing an odd number of 1" parallel spaces by starting your lines 1/2" from the edge on each side. All 4 edges must be supported. Any questions..? Happy days, Capt.Fred architect.

[Ukeluthier]

How well does Starboard hold the threads of screws?

The reason I ask is I am considering using 1/2" Starboard for a hinged seat that will rest atop a marine head. Was going to hinge it with SS piano hinge, but the screws need to be shorter than the thickness of the Starboard. I'm worried about them pulling out, despite the fact that the head itself will bear most of the weight of anyone sitting on it.

Is screwing into the edge of the Starboard an option that would allow longer screws?

[chrisjs]

Why not use machine screws with a nut/washer?? It sounds like your application would allow this approach.

[a64pilot]

You could also use a barrel nut for a flush finish