Commander 147

[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

[Commander 147]

Because as I taped this 5 foot long metal rule to the hull it looks like the high points should be the fair line of the hull and the low spots make the high points look like humps.

I can tell you with certainty that there is only one spot with a repair to the fiberglass and you can see that spot in the first picture. I am intimate with the inside and outside of the hull in this area after all the time I have spent working on it and the laminate is original and solid. I am the first person to see the inside of the keel since it left the factory full of foam and glassed over.

The starboard side is fine. It has fair lines and looks like it should.

[CapnK]

Regression/shrinkage where there was no filler betwixt hull and ballast, perhaps? Any flexxing thereabouts?

If not, I'd fill it and fair it.

[ebb]

Onefourseven, suh,
that hull there in the closeups looks choice to me. Looks very healthy. That's the original real stuff.

Gouges or low spots could be caused by an overactive former owner. Or as you show a repair nearby, it may well have been some sort of damage that was grinded out but not repaired from that point properly.

If those low spots (5/16" is ENORMOUS) are near your thin hull areas then imco this is still damage not repaired completely. I think it is excellent you grinded the mess off. Now you know what is there. And what is not there. Might help to lay an 8' batten on the good side to get an idea of what might be missing from the damaged side. Try it back and forth to get an image. Except for the gouging there can't be too much difference because it takes a lot of work with a sander/grinder to remove stuff.

Common lam schedule into a female mold is the sprayed on gel coat, then hand layering of mat, then multi layers of roving. You may be able to read these layers in those gouges. The lamination is supposed to be thickest at the keel gradually getting thinner going to the sheer. Thickness is built up with roving. Areas that needed to be smooth enough for painting by Pearson may have had cloth or mat final interior lams.

If those low spots are thin I might lay in some small pieces of fabric and two part into the depressions. Little ones first then bigger ones like you are closing up an old thru-hull. Fill to the approximate surface with cabosil gel and chopped strand. Then lam on the area pieces of 6oz, if that's what you are doing. Then do your fairing with easier to sand stuff like West System's407 powder that you mix with the same laminating plastic.
Never learned how to formulate my own powder for non-sag on vertical surfaces.

Tape on a piece of mylar film with blue tape to keep the filler flat if it wants to sag. Creates 'surface tension'. Peel it off after set.
[Just occurred to me that this is a trick used with epoxy, don't know if it works with vinylester.]

A longer batten will give you a more complete story of the hull's surface ups and downs. Longer pieces of aluminum bar are nice because of their soft edges.
Remember, these hulls were conceived as the fairest any human eye had ever seen. Each side of the hull is identical.
All of the hull's curves run without impediment into every other curve, right to the keelpost.

[mbd]

Could the weight of all the layers of the laminations during the layup of the hull have caused that side of the keel to pull away or form a "bubble" of sorts before it set up?

[Commander227]

IMHO,
I BELIEVE your keel is about as fair as any to come out of Pearson. Nobody at Pearson ever taped a baton to the keel to see how fair it was, I doubt they even checked the plug for the mold.
I BELIEVE the port side will have little likeness to the starboard if you compare the two. The entire cuddy is over 1 1/2" off center on every one of the 1775 Ensigns they built.
I BELIEVE it doesn't make any difference at all. You could fair it out to perfection and not gain an ounce of boat speed. The keel is not like the finely tuned airfoil on a modern fin keeled boat, more of a blob filled with lead.
I BELIEVE you could drop the weakest hull ever to come out of Pearson in the 60's into the drink from 30,000 feet and not suffer any damage. The only force I've ever seen to do any real damage to a 60's era Pearson hull is water inside the boat freezing (and that includes coming off a trailer at highway speeds) so I question the need to reinforce.
I BELIEVE the work you are doing looks very good and the boat already weighs 5500# so a few extra pounds of glass and resin certainly are not going to hurt anything if it helps you sleep at night.
I BELIEVE that like raising a teenager, you need to pick your battles wisely as not to run out of stream (and money)before the job is done.
THIS I BELIEVE
Mike
C227