Commander 147

[Commander 147]

The Florida heat and humidity were not as oppressive yesterday so I got some things done.

The first picture is a template I had made previously for the fiberglass bulkhead I wanted to stiffen up the keel with. The bulkhead was 2-1/2" wide at the bottom and 6" wide at the top. It was 18" tall. The bulkhead was made from 6 layers of 1708 biax and after it kicked I used my pattern to mark the size and cut it out on the bandsaw.

The second picture is the bulkhead installed with just the fillets.

The third picture is after I tabbed it in. The dark line down the center is a refferance line I drew on the bulkhed with a dry marker to help me line up the biax tabbing when I was putting it in. I left about 1 inch under the bulkhead so water can travel back and forth under it.

The forth picture is what the aft end of the ballast looked like after I had cut the fiberglass out that enclosed the foam the factory installed. You can see at the point where I stopped cutting out old glass that there is about 1-1/2" of foam between the glass and the lead ballast. I had to transision down from there to the top of the lead so I made a pattern of the area and marked and cut out the biax to the shape I needed. then I wet out a portion of the biax in the area where it needed to make that transision and let it cure on the bench. Then when I installed the glass in the boat this created a ramp down from the higher level to the top of the lead.

You can see the glass installed in the fifth picture. Following Ebb's advice I left the very end of the lead ballast open so any water getting into the keel forward of that point would have an escape route to the bilge.

[Westgate]

Bulkheads look great!

I am wondering what function these bulkheads serve? Does the hull need reinforcement along the bilge?? I am in a good position to install similar on Arthur...just need to know why!

Thanks for some collective wisdom.

Andrew

[Commander 147]

What I am starting to learn is that no two Ariels or Commanders are exactly alike. For example my commander had the foam aft of the ballast and fiberglassed over. Commander 227 tells me his had neither. His was wide open. And in just the few commanders I have personally seen all had some differances in how they were built. All similar but all differant.

When I took all the foam out of my keel the fiberglass on the sides was in my personnal opinion very thin. the sides would flex very easily. Which they did as I scraped off the foam that stuck to them. And this is one of the lifting points for the boat so just to be on the safe side I decided to strengthen the area with a bulkhead. My personality pushes me to eliminate any potential for failure so I added the bulkhead. Your boat may not it.

[ebb]

FLEX??
If you are thin down there, where you should NOT be thin, perhaps laying in some Xmat, or similar, should be done now.
I would lay the cloth along the hull interior up onto the bulkheads so that the hull is tied one side to the other - and made thicker.

Tying the boat together with those small blkhds makes a very STRONG 'I-beam' structure.

Consider doing this where the ballast ends also.

[Westgate]

Ok that makes sense. I have spent a bit of time in the bilge and have not noticed the flex you mention. Prob as you say no two were made alike. My bilge is wide open and the pins for the grundgen go thru solid FRP. Could be a PO removed all the foam?

I agree with the better safe than sorry approach so I'm going to ebb-o-fy with bulkheads too. Cant hurt and looks pretty straightforward.

Andrew

[Commander 147]

I have to say the added bulkhead makes a hugh differance in the rigidness of the aft end of the keel. But another added bulkhead above the aft end of the main ballast and biax tying that one to the other one I already installed would make the area incredibly strong. I will have to take a serious look at that.

Another issue I have and I don't know if the Boat came out of the mold that way or if the Vermont freeze thaw cycles caused it with the wet foam in the keel. But I have some humps in the port side of the keel in the area where I took all the foam out. I've sanded off the filler the boat yard had put on the keel in that area and it is not a repair or anything like that. It is the original fiberglass that makes the humps. Since this is also the area where the boat yard had sanded through the gelcoat I figured I would finish sanding of the gelcoat in that area so the epoxy would adhear better and fair the hull with some epoxy and microballons then after fairing it out apply the layer of 6oz cloth over the epoxy filler and and finally fair that out before I redid the barrier coat and bottom paint.

Opinions on my plans are welcome.

[ebb]

Humps.
Since the Commander was originally laid up in a female mold,
the assumption with a whole lot of certainty is that there would
NOT BE ANY FACTORY BUMPS IN THE HULL.
That is bumps that stick out on the hull.

Any bumps would come from a repair.
If you have access to the inside of the boat opposite any bumps on the outside,
you can probably look down at the roving that Pearson put in and see that it is original, or not.
Pearson's work is often competent but funky - and anybody else's repairs of any age will stand out like a sore thumb.

Sitting here in California I can easily say that I would grind ANY humps flat. Carefully. A bump could be some kind of wierd blister. Should find out what the hell the bumps are. And then fair, repair, and lay on the 6oz.
BUT befor you start grinding a bump:
If you look down into the bilge and you are seeing the signature Pearson layup and you are sure there is a bump on the ouitside - this is not possible.
I would use a batten to REALLY MAKE SURE that any bumps are really bumps and not an area that has hollows around an island that is not actually standing out. Hollows are more likely than bumps in a nonrestored hull.



[The 6oz cloth is not going to add thickness or much strength. Most will agree it is the best way to add a thick supported layer of epoxy barrier. The cloth is light and easy to apply. Another layer or two could be considered if you truly have a thin factory lamination in the area. Put the smaller piece on first, the a larger, then the largest over all. Seems backwards but I think fairing will be easier and there are fewer seams.]


The best test for hull soundness is thumping it. If there is a dull thud you have no other choice but grinding down to green fiberglass. You have to grind all white fibers away.

Build back up thin layers so that removal is easy. If you have to.
A couple bendy wood fairing battens for horizontal and vertical testing are good. You can pick out hollows and bumps real easy with these.

A piece of thin, sharp, stiff gauge metal is good for dragging over just applied fairing compound. Slather the compound on, then drag the steel over the surface, bending the metal to conform to the general curve of the hull.
Imco