Fiberglass Deck Leveling Block

Hey All,
This spring I'll be putting together some sort of a fiberglass deck leveling block on my cabin top in order to mount the thru-deck fitting for my little Dickinson Newport Solid Fuel Heater. I just thought I'd go out to the hive mind here to see how you guys would do this, were it your project. The manufacturer's graphics depict a teak leveling block, but that's just one more piece of brightwork to maintain and I already don't keep up with the brightwork I have now.

The flue pipe is 3'' and the manufacturer specifies a 5'' deck penetration to be surmounted by a 7'' diameter deck fitting. My thought is to drill the 5'' hole in the cambered deck first, and then build up a sort of cardboard and/or plastic form around that, with a wall inside of the 5'' hole and another outside the 7'' diameter that the base will need to be. I would then fill in the space between the two walls with fiberglass chopped strand and epoxy resin. The outside can be ground smooth, bondo'd where necessary, and then painted.

Info from the manufacturer, including some graphics and pictures:
http://dickinsonmarine.com/dm/wp-co...50-17-050-18-050-Installing-a-Deckfitting.pdf

What do you guys think?

 

First, don't use Epoxy. Polyester or Vinyl Ester is less UV sensitive.
If you don't want to maintain bright work, you don't want to keep coating Epoxy.

Second, You don't say what sort of surface you are working on. I cant think of any surface that you can rely on the "cap" material to adhere to the deck or roof, even Epoxy.
You are probably better off making the cap as a separate item, and using one of the SikaFlex products to ensure a waterproof seal. They are more flexible.

 

Made my last one out of coosa scrap I was able to scavenge. Did a ring in ring one like you mentioned, used rings made from cheap pliable Wal mart cutting board taped to essentially make dams/forms. This was on a bigger Dickinson so larger diameter. We just layed up strips and straps of combi into resin. End product was super thick and probably overkill. We ended up contouring it post cure with a grinder... next one was coosa.

 

Sorry, you're right. It's a fiberglass cabin-top, about a quarter of an inch thick or so, not cored. Mid-1960's construction from Ontario, Canada.

 

Nice, I hadn't thought of that, but I've seen a couple of projects done with coosa and I like it. I'll have to look into that.

 

It's the easy button for things that used to be ply for me. Contours easy and seals up easy.

Just saw your location. Someone over there has gotta have a chunk of it or a similar sitting around. At least when we cut out our dry stacks holes in the deck we always had a nice big round disc that would be perfect for that.

 

Oh yeah, I don't doubt for a second that I could scare up some Coosa nearby without too much effort. How would you finish it? Would you fiberglass around the outside? Bondo it smooth? Or just paint right over the coosa? It seems to me like it would need some sort of finishing work.

 

I prefit it for the slight camber we had on the top of the house (mine was doubled up to about 2 inches). Cut out the shape with a bandsaw and a large hole saw (could probably jig saw it if your normal and don't have a gunny sack of big hole saws.)

Had a fairly large diameter tapered router bit and just rotated it on the bit, it did an OK but rough job so a random orbital made it look homogeneous and radius the edge of the topside.

On the heater I did some really tight weave light weight cloth over the top after structural putty bonded it down and covered a multitude of fitment sins. Boat was poly so all was done with poly and gel coat over the top.

I've made pods for flush mount led lights up under flybridge visors and those were structural putted down and gel coated. Some are several years old and seem to be nice and sealed.

I'm only a few years working with coosa, but my last project uses just shy of 5 cases so it's not nothing. It's dust likes to stick in its surface, I use a filtered air nozzle after a once over with a shop vac on all parts pre lamination. It's given me the most consistent adhesion with coosa. All foams seem to do this but coosa dust seems harder to clear from the surface.