When is flotation not flotation?

[dcurle]

We did the bow flotation this weekend as well. Pics aren't much different than GreenLakes so I'm not posting them all, but here is a link:
http://www.flickr.com/photos/davidcurle ... 714149748/

One of the pics shows the cavity in the keelson looking aft. I took this pic by sticking the camera into the bottom of the bow chamber and pointing it aft.

Other learnings and factoids:
- We took 30 more pounds of foam out of this chamber, which makes a total of 160 pounds including the 130 we took out of the benches.
- We found that a serrated bread knife worked well to cut the foam pieces. These had to be cut to be removed because they are oriented port-to-starborard, not bow-to-aft like the bench foam.
- We found that a tile-cutting blade on a jigsaw worked really well to cut the fiberglass. We started the cut by drilling a 1/2 inch hole on the cut line, then let the jigsaw do the rest.

[ctenidae]

I cut the access ports in my seat tanks this weekend- I'll take pictures tonight and post. Pretty clear that has never been foam in there- there are epoxy strings criss-crossing the interior. Interestingly, inside each chamber there is a ~2 inch diameter cardboard tube glassed into the floor, with only one layer of glass. Can't figure out what the purpose of them would have been. Odd, though.

[seandwyer]

so what is the consensus as to best cutting tool for this operation? I've heard regular jig saw, now jig saw with a tile blade, dremel tool and rotozip and drill type hole saw. has anyone found what they used to be the best option / and or wish they had used something else? I'm afraid of cracks and splintering - deffinately tape will help as shown. Dcurle - did you find the width of the jigsaw to be hard to turn in the circular cutting direction?

[K.C. Walker]

inside each chamber there is a ~2 inch diameter cardboard tube glassed into the floor, with only one layer of glass. Can't figure out what the purpose of them would have been. Odd, though.

The stringer inside of the tank doesn't seem odd to me. It's a flattish area of the hull that can definitely benefit from stiffening.

KC

[GreenLake]

I cut the access ports in my seat tanks this weekend- I'll take pictures tonight and post. Pretty clear that has never been foam in there- there are epoxy strings criss-crossing the interior.

Probably not epoxy (because the DS was built with Polyester resins).

Interestingly, inside each chamber there is a ~2 inch diameter cardboard tube glassed into the floor, with only one layer of glass. Can't figure out what the purpose of them would have been. Odd, though.

I found the same kind of tube in my bow tank. Length about 1'. Other than serving as a handle to maneuver the hull during fabrication, I can't think of a use for it.

[GreenLake]

The stringer inside of the tank doesn't seem odd to me. It's a flattish area of the hull that can definitely benefit from stiffening.

Those don't seem to be structural. I've not seen one inside a bench yet (haven't looked inside mine yet) but my guess is that they are not running the full length. If I'm wrong, I'd like to find out, though, from someone who's seen these.

[GreenLake]

so what is the consensus as to best cutting tool for this operation? I've heard regular jig saw, now jig saw with a tile blade, dremel tool and rotozip and drill type hole saw. has anyone found what they used to be the best option / and or wish they had used something else? I'm afraid of cracks and splintering - deffinately tape will help as shown.

You've left out drilling a series of closely spaced holes with a 3/16" or smaller drill bit, followed by snapping out the "bridges" between the holes. It sounds more tedious than it turned out to be and I'm glad I didn't try my jigsaw, because it would have been more awkward to position than the drill.

I did not observe any worrysome cracking or splintering. The material is quite tough. Note that the "lip" of the usual deck plate fitting will hide even major sins, so the tolerances aren't critical. I drilled a little on the tight side (on a smaller circle) and then sanded the hole smooth, and got a reasonably tight fit.

[K.C. Walker]

I used a circle cutting jig with a laminate trimmer and a standard 1/4 inch bit. It makes a perfectly round hole with very smooth edges to an exact size. A Dremel should do the same but just be a little slower.

KC

[ctenidae]

I traced the outline, then cut it out with a plastic cutting wheel on the Dremmel. Started with a rotary saw bit, but it was going very slow, and got very hot after only an inch or so. I doubt the saw bit was the right one- works great on drywall, not so much on fiberglass.

As to the tubes, I doubt they're structural, since the run lengthwise, and are only about 1 foot long. With what appears to only be 1 layer of glass on them, I have trouble imagining they'd be much good for lifting or maneuvering the hull, either. I'll post some pictures tonight. Maybe I'll cut the access port ion the bow tank, too, and see if there's one in there.

On a different point, there are drain holes with plugs in each seat and the bow tank. I couldn't cut the access ports around them, so had to leave them there. Is it worth it to glass over them, or pointless, and I should just leave the plugs in them? The plugs are about 1/2 inch off the floor, so not very good for draining, anyway.

[K.C. Walker]

Regarding the cardboard tubes: now I think it's really odd and have no clue what they would be for. Probably one of those obscure in-house things that helped with assembly somehow.

I left my drain holes but thought about glassing them, as well.

I tried the same Rotary saw/zip tool that came with the Dremel. I toasted mine pretty quick, as well. Fiberglass eats steel pretty fast but carbide lasts long enough to do the job. Of course, it's not much good for anything after that.

KC

[GreenLake]

I left my drain holes but thought about glassing them, as well.

My plan is to leave them, but use a sandwhich of rubber and steel washers to close them, with a wing-nut on the inside. If water does get in the compartment, it's much easier to drain from there.

Corks would work, but I tend to knock them loose or into the holes.

[K.C. Walker]

[/quote]My plan is to leave them, but use a sandwhich of rubber and steel washers to close them, with a wing-nut on the inside. If water does get in the compartment, it's much easier to drain from there.[/quote]

I like the washer idea. I've got those stoppers with T-handles. I figure sooner or later somebody's going to snag a toe on those. And, of course you meant stainless washers.

KC

[dcurle]

Dcurle - did you find the width of the jigsaw to be hard to turn in the circular cutting direction?

Sean, yes maneuvering the saw was the only issue with each method. I drew my circles, then practiced the motions of cutting with the saw before actually cutting. I was able to cut all parts of the circle with either a clockwise or a counterclockwise motion.

My ability to do this may have to do with the size of my jigsaw, which, now that I think of it, might be a little small. But assuming your saw can handle the angles, then the tile blade (which by the way is also explicitly recommended for fiberglass on the packaging - Vermont American brand) made a very clean cut. I just sanded it off a little after the cut to prevent subsequent splintering.

[ctenidae]

My seat tubes- boat is upside down, so adjust your perspective.

Only theory I can come up with is they're spacers for stacking completed hulls. It's only a theory, though.

[Imgaryo1]

If you are lucky enough to live near the desert, open up your access ports and go for a ride. When we went out to the NACR at Huntington Lake, California a few years back the boat lost 10 pounds of water weight driving thru the desert. This was a boat that always weighs in at exactly 575 so we had to add 10 lbs of lead to bring her back up to the minimum weight requirement.