Skerry Hull repair/refinishing

Builder's Forum
1

 

 

I have a skerry that I bought last year.  Had great fun all summer learning to make it go in the direction I wanted (not always successfully).

But now the hull is looking a bit ragged.  See pics below.   My plan is to paint the hull.   So my questions are, do I just need to sand until the flacky bits of varnish  are gone?  The part that seems to have no epoxy left, does that need to have some epoxy added?  Or, please say no, do I need to sand the whole hull down to the plywood?    From reading other posts, it would seem I am going to need about one quart, does that seem right?

Thank you for any help and advice.

https://live.staticflickr.com/65535/49931560961_8df50bce46_c.jpg

https://live.staticflickr.com/65535/49931873507_991e1a7b86_b.jpg

https://live.staticflickr.com/65535/49931558461_de34b5d3ec_c.jpg

Keith H

Boston, MA

2

   OK, well it seems my first attempt at embedding photos was a failure.  The links work, but will try again in a bit

 

Thanks

 

keith 

3

   This should work

4

Oohh, that black stuff is fungus in the wood, probably under what epoxy had been applied by the builder. That's going to need some serious attention if it's progressed deep enough to penetrate the plywood's outer veneer layer.

Once you've scraped off what's left of any varnish & epoxy that's still there, you may be able to arrest any further rot progression with applications of dilute household bleach then thorough water rinsing followed by sufficient time under protection to let the plywood dry thoroughly.

The lighter surface that shows varnish peeling from the epoxy, which seems to be peeling too near the seam (inside or out? I can't tell!) shows a bit of fungus too but since the surface finishes have peeled it's not as extensive, what water penetrated the finish coatings has long since dried.

Scraping down to sound plywood's often easier than sanding and usually less work, certainly less mess. Wood fungus isn't something you want to be breathing in either so wear a respirator whether you choose to scrape or sand.

Wherever you see what's in those pics you need to get down to sound wood before beginning your efforts to properly refinish your treasure!

 

5

In general, what spclark said. Specifically for this area:

My take on this one is that the bottom panel is in serious trouble. It's lost all its protection in some spots and the wood is compromised.. The fact that the edge has been exposed to water is bad, It seems to have sucked water into the interior of the plywood panel. This is not just a refinishing job, it's a restoration. But it is definitely fixable.

What I'd do if it was my boat:

1. Determine if there's rot and how much. Find an area of the boat with the same kind of seam pattern that is OK and tap on it with knuckles. Note the sound that it makes and the feel. Do the same thing with something hard, such as the handle of a kitchen knife held by the blade. Then push on the wood with your finger, paying close attention to the feel, how/if it flexes and if it makes any kind of sounds.

2. Repeat on the bad spot. Look for differences in sound and feel from the good spot. Specifically, rotting wood will make duller sounds. It will be quieter, mushy and muffled. The wood may feel softer. It may move and flex. It may be possible to push a thumbnail into it. If the area seems bad, try lightly pushing into it with a sharp knife point. If it goes in easily, there's rot.

3. Once rot is identified and defined, I'd mark out an area at least 2" wider than the rotten area and cut it away. I'd examine the cut edges and make sure that the wood is sound. If not, cut more.

4. When all the rotten wood is gone, I'd replace it with fresh and then get on with the refinishing.

If somehow you're lucky enough that there's no rot, then I'd sand away all the damaged wood and build the thickness back up with fiberglass cloth, after which it'd be just a refinish job. Be sure to extend the new glass at least 2" beyond the repair.

This is a bunch of work. I know, but it's a lot less than building a new boat from scratch. If you don't do it, the structure and strength of your boat will be compromised and it could turn into a major safety issue. The Skerry, especially when compared to traditionally built boats, has very few frames because the pre-stressed hull panels are carrying the structural loads. That means that your panels must be in good shape or the boat may collapse.

If you don't feel that you have the skills, time or tools to do this and you're near Annapolis, CLC offers repair and restoration services.

Good luck,

Laszlo

 

 

6

Excellent advice above.  The presence of the mold/fungus indicates to me that the boat was built with lower grade plywood.  When you perform Lazlo's tap test, this will tell you if the problem is just cosmetic or if it is structural.  If just cosmetic, then scrape/sand then paint or varnish as suggested above.  If the damaged areas are structural and wide spread, then you have to ask yourself if the boat is really worth the effort.  If you do decide to repair, you might be better off not painting the boat, because that will hide any new problem areas.  If you varnish, you will see problems when they are small and easier to fix.  

7

  Well this is a tad depressing.  Thank you very much for the replies. 

I have the time. I have the tools.  Whether I have skill remains to be seen.  I am finishing up a stitch and glue decked canoe now, and that seems to be going ok.  

I guess there is nothing left to do but to get crackin'. 

 

Keith

 

 

 

8

You might want to read John Harris' piece on this topic:

https://www.clcboats.com/life-of-boats-blog/what-happens-when-stitch-and-glue-boats-age.html

May the Brute Force be with you, but not the Blunt Force Trauma!

.....Michael

9

Keith, if you're building another boat you already have the skills to perform a successful repair! You just need the confidence that comes with seeing it done with, and the results that come of the effort. You'll do fine, and you'll come away with more knowledge and a deeper skillset than you currently enjoy. Your future projects will be even better for your efforts!

10

   Thanks for the encouragement and the link to Harris's piece.  Should be able to get started in the next two weeks. 

 

This whole boat thing is rather addictive.  Once I finish the canoe, and the skerry, I am looking at building the Jimmy Skiff.  Or the Passagmaker.  I fear for my other hobbies.

 

Keith

 

11

FWIW, even quality marine plywood, such as okoume and meranti, can develop the dreaded black ick.

Laszlo

 

12

Thank you all for some very interesting reading.

Any comments on how the boat got this way? I guess wood was bared which led to water infiltration and fungus. But how did that happen? Has the boat been used hard, is it down to the build, or a combination of both?

We're going into our 3rd summer with the NE Dory. It's garaged and trailered, and looks almost like new. Our repairs are related to using the boat. We've had to fill gashes in the daggerboard twice from hitting uncharted rocks. Our rudder has some wood exposed that needs epoxy. There's a little wear and tear where the tiller handle rubs the rudder and where the spars rub on the mast, and where the mast rubs on the mast thwart.

13

   Here is my theory.  I bought the boat knowing nothing about boats.  It had been stored in a barn for some time, maybe quite a bit of time.  It looked good to me since it was shiny and I wanted a boat NOW.  In reality the varnish must have thinned to nearly nothing, or there were cracks I didn't notice.  The boat spent this last summer in the water, with some time out of the water, in the sun.  The water came in through the poor/non existant varnish.   The sun killed the epoxy. 

That's my theory.  Hopefully someone who actually knows things will chime in

 

Keith

 

 

14

   Did that texture in the epoxy happen before or after the damage? the pic with the black stuff in the wood the epoxy texture is not at all smooth looking.  Made me wonder how well the epoxy was applied if care wasn't taken to smooth it all out with a sander.  But not sure if that was a result of the leak or not.

15

   As spclark stated so well "if you are biulding a boat you have the skills to do the repairs". Repairs are a great skill builder as they are rarely the same twice. Always some detail to work out - how does this location get patched/spliced/clamped...

A really good resource for repairs is on the Guegeon/West System website - tons of how to repair this or that.

Repairing boats becomes additive too. I maintain (repair - as a volunteer) 16 420s, 14 Optimists, and 9 Flying Juniors for two summer sailing programs and a high school sailing team. Even though they are not wood, the concepts are the same, as CLC stitch  and glue boats are really wood cored fiberglass boats. I find the repairing fun, and I am pleased everytime I keep a boat out of the dumpster!

I have to admit that I have looked at some damaged, neglected boats and cut them up with a sawzall and sent them away. Not everything can/ahould be saved! But save those that can be saved is very rewarding.

So repairing can be as satisfing as building. 

Enjoy, Joel

16

   Here is a few more pics if that aids in diagnosis.  It did not look like this when I pulled it out of the ater last fall. 

 

 

 

17

That looks like total varnish failure. It looks as if the original builder did not apply or maintain it properly (or both).

I see a lot of sanding and scraping in your life.

Laszlo

18

Where there is, or will be, (a) layer(s) of glass on both sides, then it's probably easiest to treat the funky wood with penetrating epoxy to re-solidify it. The wood is acting as a core when sandwiched by glass on both sides, so you just want to stop the funk from progressing, and make the funk stiff enough to positively locate the glass against foot, water, and trailer pressures. Caveats: the wood will look a little funny, from the PE and the fact that it's already funky; and the boat will weigh a little more, both from the added PE (it won't take much), and the added glass where perhaps there wasn't any before.

But to go that route requires getting back to bare wood on at least one side, which the outside of this boat seems to need anyway. A heat gun and a putty knife (and a real respirator!) will allow the glass to be softened and removed in decent sized pieces. See Nick Schade's video about doing this here: https://youtu.be/BHNHXD-g2N0