Fixin' a hull seam crack....

[Mizzousailor]

When I bought my 1983 SC 19, I knew it had a small crack at the bottom of the forward port hull, right along the seam. I did some exploring yesterday and discovered it's actually a 4-inch-long crack that a previous owner had filled in with Bondo and gel-coated over. I cleaned out the Bondo with a knife. It looks like the previous owner ran her aground at speed.

I've repaired fiberglass decks before with glass and epoxy, but am unsure what to use on this one, since a small portion of the foam core is now exposed. My initial thought: Inject 3M 5200 into the gap (it's about 1/8 inch wide) and let cure, then come back with a couple layers of glass and epoxy. Sand and repaint. Advice? - Wes

[Matt Haberman]

Wes,

I would recomend against using the 5200 to glue the seam back together. I think making a putty from Epoxy and cabosil would be a better solution. Then cover that with a few layers of glass with the fibers running at 45 degrees to the seam.

[Kevin Keller]

I am posting a PM Wes and I were having.


Hi Wes,

Did you look at my post, "Refurbishing a Supercat20"? It should cover what you need to do. It sounds like an easy repair. You should post some pics.

I would not use 5200. If it is the same stuff I am thinking, resin would not stick to it.

Kevin



Hi Kevin......I just read through your post. Excellent workmanship on your part. Thanks for the tip about 5200.....I was a little concerned about epoxy adhering to it, though it's incredibly strong, tough stuff.

I do have another question perhaps you can answer. After cleaning out the gap, I noticed the core material was a little damp. I think water got in when rain ran down the side of the hull and collected along the bottom seam. I stuffed paper towels in to blot up as much as I could, but they kept coming out damp, so it's clear there's a fair amount of moisture in there. Got any ideas how to dry out that core, short of cutting a hole in the hull? With winter coming on, I for sure want the core to be dry so there's no freeze damage... Thanks for your help. - Wes


Wes,

I had my hulls out of the water for probably 6 months and when I was working on the bottom I noticed the foam was a wet also. If I recall correctly I took the fiberglass off until I found dry foam and then put heat on it to dry the wet foam. I took a heat gun to it and then left a light bulb near it a few days which seemed to dry it out. You want to make sure it is dry before you fiberglass it again. You can scrape the foam away and either replace it or fill it in with glass ball/epoxy mix Matt talks about. While you are at it you might want to put a new strip of fiberglass along the entire bottom to prevent this from happening again.

Kevin

[Kevin Keller]

I would imagine your water was probably left over from when the previous owner grounded the boat, he might not have dried it completely before repairing.

I am not sure if the core is open or closed-cell foam, Matt can you confirm? This would affect whether the water can travel through the foam or not.

[Mizzousailor]

Thanks guys for all the suggestions. I tried an experiment the last couple of days and it seems to be working. I stuffed heavy paper towels into the crack, leaving about 6 inches hanging down where air can reach it. The setup seems to be wicking a lot of water out of the foam, where it evaporates in the paper towel. The boat's sitting bows-down on the trailer, so the crack is at the lowest point. Maybe this will work without having to cut open the hull.

I too am interested in knowing if the foam is closed-cell or acts as a sponge. - Wes

[Matt Haberman]

Wes & Kevin,

The foam core material is a structural closed cell foam, either Klegelcell or Divinycell.

[Mizzousailor]

Thanks Matt.....very helpful.