CRACK!!

[jray]

Ok, working on the strut this evening I noticed some wear spots. I figured that some sanding was in order for certain areas of the sleeve that would help even things out on the sleeve to strut fit. While under the boat I found a hairline crack just at the front bottom radius of the sleeve. It shows slightly forward and my thoughts are it was caused from moisture under the fairing compound between the fairing compound and the fiberglass and ply. Winter temps expanded moisture there and the crack appeared. My initial thought was to dremel out the area and put thickened epoxy. Also thinking about some 4200 to fill the area. Time is clicking by and my first race is this Saturday if I can get everything ready and launch in time. No water is in the hull and I believe the crack is between the hull and the fairing compound. Looking for ideas and input.

[micah202]

hmmm,,go with the 4200 (fastcure) for now and get on the water!

..proper fix would be to open up damaged/delam area with a dremel or grinder as far as it goes,perhaps a 'wet-cure' epoxy if you're dealing with moisture,,,,,glad I got mine in time!.

....don't be cursed by builder/sailor syndrome and think you -have- to open it up now!!

[Kevin]

I agree. The sleeve is filleted and taped into the bow and frame 18 right. If there's no sign of issue on the internal side of things, then I'd go with the 4200 solution for this weekend.

Easy to monitor after a day of sailing to see if there is any change. Especially if it's a heavy wind day with the kite up. If yes, then stop sailing and address it. Otherwise, put this on you winter maintenance todo list.

Cheers, Kevin.

[jray]

I maybe should have stated it is the keel strut. The small crack is on the forward radius of the keel box sleeve. It isn't into the ply just under some fairing material. I think I'm going to dremel it and fill with thickened epoxy, as my plan is to leave the boat in for the summer. It wasn't there when I re-painted the bottom last fall so must have happened over the winter storage. Wouldn't sweat it if it was topside but the bottom is another thing.

[admin]

slight hijack, or maybe not, Jray, but excuse me for stepping on your thread.
In the same area you are repairing, I have some significant gaps between the keel sleeve and the bottom plywood...(see drawing)

Once I cut the sleeve flush, I was thinking of filling those gaps with a mash of:

- cut up chopped strand
- WestSystem 404 (high density filler)
- and 105/205 pox

to a semi-stiff mixture and mashing that stuff down into the gaps...pretty deeply, the plywood layup is four layers of 6mm meranti on the bottom, inside the keelbox.

think that'll work? The idea is to keep water out of the boat....

Gaps.jpg

(edit) actually, like a dumass, I already cut the sleeve flush with the bottom...wish I hadn't as it would've probably helped to have kept it intact before trying this.

[Chad]

Bevel the outer ply surface a little, sand/bevel/scratch the exposed bit of sleeve to create a sort of fillet-shaped void. Get some milled glass filler (fine, or up to 1/8" fibers), and mix a thick batch to tool into the fillet-shaped gap. After you sand this down flush to the hull bottom, you'll have a good connection between your outer glass and the sleeve.

If it was me, I'd shoot for a 1/4" to 1/2" fillet size.

You can also rout/sand/grind a recess a couple inches all around (and including) the sleeve, then do your fillet bevels, then the fillet goop, sand, then lay on several layers of glass in the recess until it is flush and fair to the hull surface. The recess wouldn't need to be any deeper than the sleeve wall thickness.

I'd draw you a couple quick pics too, but I'm sitting in he park while my daughter plays in the wading pool. ,-)

[admin]

thanks Chad! i think I got it, but a picture would be great. However, wading pools always take priority!

[Chad]

tried to post a drawing, but "forum quota is exceeded" message comes up. Do I need to create a new login/sockpuppet?

[admin]

I have no idea what's up with that. I got the same thing.
I'll go on the ACB and see if I can up the quotas a bit...otherwise, another account may be necessary!

[admin]

Oker dokes, try it now!

[Chad]

Graphically, what I tried to describe verbally above:

sleeve steps.jpeg

sleeve cutaway.jpeg

[admin]

B-U -Tific! Man, that is really helpful. I doubt in practice mine will be quite that neat& tidy, but at least I have something to aim for. As mentioned prior, thanks Chad, you are a tremendous asset to our community of rank amateurs (speaking for my personal community, at least

[Chad]

My situation isn't exactly as we've discussed above, but here's the recess I've cut around my keel slot to receive a bunch of reinforcement. I used a router with a rabbet bit set a little more than 1/16" deep, and a pin (bolt and a couple nuts in this case) sticking through the base to ride around the slot perimeter and control the width of the cut. Then I beveled away the perimeter to create a scarf for the fibers in the keel area to tie to the hull laminate. The keel reinforcement will need to be re-faired into the hull bottom.

This is a little backwards to the way others might do it- it would be more efficient to do most of this before the hull gets glassed. I needed to use the uncut hull bottom for a mold for a keel opening plate, so I couldn't do it that way.

IMG_0498.JPG

[Chad]

And more progress on the keel hole reinforcement.

I laid up a length of L-plate, cut to size here, with the other biax bits ready to go:

IMG_0504.JPG

My keel's jibing shims will bear against these L-plates, so I need them to be very straight and square- I couldn't just use hand laid cloth in the hole as the finished surface. So I put some hand laid pieces down first, trying to make sure all the corners are well reinforced, then added the L-plates and a pair of mdf cauls that I could wedge toward the sides:

IMG_0505.JPG

I also spent some time this morning working on the fairing plate for the oversize keel hole. It gets attached to a mini keel sleeve, and then I'll cut its outer edge to some aero looking shape, and bevel the edges. It gets held tight to the hull bottom surface with a couple lengths of bungie.