Newer boat seat framing vs plywood

[baileyuph]

Customer with a very expensive (to me) boat has seat board frames made out a hard synthetic material, some stuff I have been seeing for a few years.  Anyway, the seat was brought to me and when it was opened up the frame was cracked in a number of directions.  I showed it to him, he said check them all (the rest of the seats) and I will make plywood boards to replace that stuff.  He had several go bad (they crack).

Like I said, this has been observed by me, the synthetic material cracking that is, my question is have you boat people been seeing the synthic crack phenomen?  That has to be frustrating for boat owners, they logically wish for something that won't rot but get something that literally cracks in all directions.  Now, the answer, for him and others is to go back to plywood.  

To be honest, I have done Triton interiors, recently and their plastic frames do not generally crack like this "very hard" synthetic material does.

What has been other experience with the cracking problem?  Replace with plywood?

Doyle

[brmax]

Do you think 3/4 is what you might replace it with?, Is this is on a swivel type mounting or some other area, Im taking it that these arent getting stepped on but still having this problem.
I would be seriously bummin

[JuneC]

Is it a very dense black plastic?  If so, it's probably ABS - and it's prone to shattering.  I like the Starboard light stuff (think it's called Starboard XL).  It's plastic, strong, bendable, easily worked, expensive.  Starboard is better, but more expensive and heavy.  It doesn't shatter on impact or under stress (though I'm sure there's a point where it would crack as well).  I hate the black plastic stuff.  It holds staples like crazy - which makes it a pain to tear down, and it cracks.  Plywood is VERY tough stuff and is reasonably priced, but you have to keep it dry, even the marine grade.   I typically push the expanded PVC if it'll be backed by something else like the fiberglass hull or deck.  If it has to stand on its own, the Starboard XL is good.  There's a few OEM manufacturers who use some white plastic that's apparently blow-molded, and it's really tough stuff, but not easily fabricated or repaired using tools and materials typically found in an upholstery shop.

June

[baileyuph]

The interior of this boat does not look like it was walked on and the bases do have broad support to lie on.

The material that is cracking turns out to be pretty white.  Very hard and obvious brittle to a degree.  After transferring some of the upholstery, as a test I hit the board take off with a hammer and the center most part of the board - very brittle.  But the perimeter of the white stuff was hard, I couldn't crack it.  It will take a staple, but that process was conducted by a very thin wire staple.  I do not know if it was as big as a number 7?

I just got done with transfering OEM, still nice upholstery to plywood.  This customer will not let this boat interior get wet, you wouldn't believe the condition of it, a rare boat guy.

You know, I didn't measure the thickness of the plywood, but 5/8 ths is my guess. 

The transfer process is tedious, new posiition of everthing, foam and cover and the rest has to be down to the same staple hole (almost).  Location of everything is being marked on the take off board then transferred to the wood board (foam, seam, cording locatiions, etc), a pain like I say, but is working.

I have the brand of boat noted at the business, will pay attention to that again.

Doyle

[brmax]

Im curious, though i havent seen any white. Is this plastic a molded with webbing style or structure or just flat, I actualy just see what you all put up. Or what i had in my boats, I did save to my fav/products a white material before thats was mentioned here. And thanks on that. Any pics on this?
That process would be tedious i agree, thanks and good day

[baileyuph]

The white board (plastic/synthetic/whatever) is the same shape and thickness as the prepared plywood.  The plywood actually selected to be equal in dimensions to the white board, it is even coved around the edges.  We are using the OEM upholstery and wanted the fit on the plywood to be the same down to a knats toe, and it does. 

Doyle

[Mike]

I don't know if its abs or pvc but the only plastic ive seen cracked is  the black this 1/4" thixk stuss that hurricane  uses on there curves set back that have holes holes fit onto the clips s thin so it bends
usually cracked hear a hole at the bends ive band aided then by patching the, back with a piece of canvas glued and stapled on this plastic it so thin the stapes stick through the plastic and cut my knuckle's inside

http://www.tampabaywatercraft.com/wp-content/uploads/2013/05/2007-Hurricane-237-Deck-Boat43.jpg