starboard?

[scosch]

Im new to this, both the forum and boat maintainence.
I was reading about changing/adding a seacock, which I need to do next week, and someone mentioned using "starboard" as a material for a backing block, instead of marine plywood, which I thought was the standard. What is "starboard" and why is it better and where can I get it?

[sailingdog]

Starboard is a polymer "marine lumber" that is made by the Taco Plastics corporation. It is often used on boats to make pieces that are exposed to the elements and it doesn't really require any maintenance.

I would not use starboard as a backing block for two reasons. First, I don't think it has the compressive strength tha marine plywood has. Second, it is very "slick" material, and you can have some issues getting sealants to stick to it properly. Some sealants, particularly the polysulfide based ones will attack the material as well.

You can get it at many marine chandleries, like West Marine, but be prepared to pay through the nose for it. An alternative source for it is your local sign supply wholesaler. That's where I've found it at much more reasonable prices. However, you generally have to buy a half or full sheet of the material.

If you use epoxy... coat the epoxy thoroughly with epoxy, after drilling all the holes for the various fasteners you're going to use. If you're going to screw the seacock flange to the plywood backing board, instead of through-bolting, which is recommmended, then pot the holes with thickened epoxy, much like you would do for a cored deck.

[erps]

I've not purchased "starboard" proper yet but I've done a few small projects where I needed a similar material. I went to the local hardware/drug store and bought one of their small plastic cutting boards. A quick reasonably priced alternative material.

[stevemac00]

I just ordered starboard from this guy. Decent price and got it quick.
King Starboard Products And Prices
And I was able to get it in a color which closely matched my interior gelcoat. But this would not make a great seacock support plate.

As for the plate. I made mine to match what Pacific Seacraft does by laminating seven layers of cloth in a waxed plastic bowl mold. Take a little more work but structurally sound, no chance of deterioration and looks good.

[Boasun]

What are you going to use on the Portside?? Hmmm!?

No Maintenance?? that would be a sailor's dream.
Is the material UV protected?

[sailingdog]

Boasun-

It is uv-stabilized plastic...and seems to hold up quite well in its intended purposes, however, it is not a very strong material and should not be use where structural strength is a factor.

[Jeff_H]

The purpose of a thru-hull backing plate is to distribute the leveraged loads from operating the seacock and removing hoses. The backing plate needs to be stiff enough to distribute the loads to the full contact area and starboard is just too flexible for that purpose, especialy at larger thru-hulls such as head discharges. Cutting boards lack the strength of even starboard.

Plywood is often used for backing plates, but as SailingDog notes, the plywood should be epoxy saturated once drilled for all of the fastenings. I would suggest using MAS epoxy since thier penetrating epoxy does not produce an amine blush, which with other brands may interfere with the bond between the sealant and the backing plate.

If your hull is cored the coring should be cut back and the core space filled with solid thickened epoxy. Another better solution is to cut away the inner skin and remove the core and then build up solid glass and epoxy, tapering out onto the inner and outer skins.

Which brings me to my favorite backing plate method, which is to simply build up layers epoxy and fiberglass with a tapered edge.

Jeff

[sailingdog]

Originally Posted by Jeff_H

Plywood is often used for backing plates, but as SailingDog notes, the plywood should be epoxy saturated once drilled for all of the fastenings. I would suggest using MAS epoxy since thier penetrating epoxy does not produce an amine blush, which with other brands may interfere with the bond between the sealant and the backing plate.

If your hull is cored the coring should be cut back and the core space filled with solid thickened epoxy. Another better solution is to cut away the inner skin and remove the core and then build up solid glass and epoxy, tapering out onto the inner and outer skins.

Which brings me to my favorite backing plate method, which is to simply build up layers epoxy and fiberglass with a tapered edge.

Jeff

Yup...but that requires a lot more effort than cutting a slab of marine ply and coating it in epoxy. The point about MAS expoy is a good one... unless you feel like washing off the amine blush after the epoxy cures.

[Alden68]

Don't forget you can buy AZEK and/or Fypon PVC lumber at any lumber yard which means you don't have to go to West I am sure it should never be used as a structural element but it is UV resistent, paintable (although you don't have to) any it can be shaped/sanded with everyday woodworking tools. AZEK comes in many widths and thicknesses and is even sold as a sheet good.

[Sailormann]

I bought a sheet of Starboard three years ago for just under 300 dollars. I still have most of it. It is very hard to work with. Saws easily enough, but it feels like a big piece of polyethylene. It does not hold screws well - they cannot be tightened to any extent without stripping the material. It is very heavy, yet still very flexible - nowhere nears as stiff as wood.

The only thing that bonds it is a 3m product called Starweld, that costs 70 some odd dollars (Cdn) for about 2 ounces. I am not sure who uses it Starboard, and frankly, I am surprised that it has found a market. I bought 1/2 inch as I had originally thought it might be good material for a bulkhead on a friend's boat.

It did make a good shelf for the VCR in our master bedroom. I still don't know what to do with the other 30 square feet - perhaps I can buy more VCR's ???