Jump to content

Protecting a Wooden Keel Strip


Don Silsbe
 Share

Recommended Posts

There has been an interesting thread within a thread going on.  I thought this topic deserved its own separate thread.  The subject is how to adequately protect our wooden keel strips.  I hope we can share our own experiences and thoughts here.  They might be easier to find, when we get to that point on our next build.

 

On my Bay River Skiff and Two Paw 8, I have chosen the “no protection” approach.  My TP8 is showing wear.  I expect the BRS might as well.  I’m currently working on a non-B&B boat, which is posted on the general boatbuilding forum.  

 

Alan has taken an interesting no-wood approach.  I’ll paste that video link later.  It will be interesting to see how that holds up with use.  My experience with fiberglass is that it has lousy abrasion resistance.  I want to do something different.

 

I have been told that Dynel offers excellent abrasion resistance.  I do know from personal experience that it is an epoxy sponge.  I plan to use that only on the keel and skeg of my current build.  We’ll see how that goes.  I’ll track the abrasion performance here, but construction details will be on the other thread.

 

What about hollowback?  How do you attach it without compromising your moisture barrier?  Is graphite in the epoxy very effective?  Kevlar? Carbon fiber?  Let’s chew on this bone awhile!

Link to comment
Share on other sites


I thought of solid or hollow back half oval OR “flat” stock, brass or ss.  But I wanted a 5/8” x 1/8” it to cover the 3/4” yellow pine keel for Seabiscuit, my Spindrift 10.  Hard to find and too expensive.

 

So, I’m going with a white oak 5/8” x 1/8” (maybe 5/32”?) cut from a 3/4” quarter-round 8’ molding purchased from Lowes.  The yellow pine keel strip will be glued in place, and the white oak strip bedded (on its top) with 5/8” x #8 SS FHWS counter-sunk (flush) at 6” spacing.  If it gets torn up, I’ll just replace it.  The 8’ molding cost $9.44.  Might even get two strips out of the 8’ molding?

 

I’m considering installing it bare (i.e., no finishing).  White oak holds up well in moisture and any finish would quickly be stripped off by beach sand, gravel, etc.

  • Thanks 1
Link to comment
Share on other sites

I used White Oak for the keel strip on Suzy J, my Spindrift 11N. I haven't used her heavily, but she has been beached enough the epoxy and paint coating has been compromised. White Oak, being closed cell has held up. The closed cell properties can make gluing reliably difficult they say, but I've not experienced this. As a precaution, I took a cheap harbor freight saw blade and knocked a tooth out to make a really rough cut on the glued edge. I did not use any fasteners but I did glue it down while the cloth was not fully cured.

 

I did the exact same thing on Skeena, my Core Sound 20.3. The only thing different is I had to put a screw in the front and back to hold it down as I found straps didn't seem to work well while gluing. I shallow V cut the strip on the glued side with the same crappy blade I used on the Suzy J. The Epoxy on the hull cloth was definitely cured a few days, but the bond seems excellent. I piled cinder blocks along it on plastic to hold it down between the screws.

 

Because of the weight of the boat and it being on a trailer, I did radius the top to match hollow-back and I used short screws and 4200 to bed it. It has held up really well, although I decided to use wide bunk boards that support the longitudinal bulkheads (and the released centerboard) while trailering, so it doesn't get as much torture as originally planned with keel support.

 

I hope this helps you make a decision. They are all compromises.

 

Take Care,

Steve

 

 

  • Thanks 1
Link to comment
Share on other sites

I spent much of the last 5 seasons running my Lapwing onto a coarse sand  landing.  I used solid bronze half round over a Poplar keel.  The keel takes no abrasion notable for the 5 years and I have yet to have to touch up the paint. I pre-drilled and dry fit the entire keel strip, removed and and bedded the entire length in BoatLife LifeCaulk. My boat is trailered, but left outside for all 5 seasons. No issues of any kind.

  • Thanks 1
Link to comment
Share on other sites

I think I did my keel strip totally different from anyone else on my CS20.3.  I clamped a packing tape covered 1X4 to each side of the keel, the filled the gap with unidirectional glass with epoxy and graphite in the epoxy slurry.  I wanted to experiment with a keel strip with no screws.  So far it seems to be working, although I suspect it would/may crack it point loaded, but sand an shells seem to have no problems.   All a compromise, I suppose. 

  • Thanks 1
Link to comment
Share on other sites

It is my understanding that traditional wormshoes are expendable, sacrificial pieces.  They do not get glued down, but are screwed into bedding compound.  When they wear out, they are replaced.  If I used wood instead if Dynel, I’d bed it in some polysulfide, and screw it in place.  I’d paint it, too.

 

But what about Dynel?  Anybody?  Eric Blake from the Brooklin Boatyard recommends it for sheathing hulls when abrasion is an issue.  I thought it might be a candidate for keel strip abrasion.

Link to comment
Share on other sites

Lou Sauzedde (tips from a shipwright)  did a YouTube video a while back on the difference in red/white oak using rubbing alcohol.   That being said I trimmed my boat’s cabin with red oak, has enough epoxy to protect it from a nuclear blast.  I find white oak is ridiculously expensive in our area, and the quality is suspect.  

Link to comment
Share on other sites

Here’s my plan, as of Oct 2, subject to change without notice.  I’m going to make my keel and skeg out of all Poplar, per the original plan.  I’m going to lay down one or two layers of Dynel onthe bottom face only.  This is new.  I’ll use tough fumed silica as filler for the weave.  If it performs poorly, I’ll take my power planer or belt sander and eliminate it, replacing it with a 3/8” thick “wormshoe”, the full length of the keel.  I might add a brass strip to the stem, because the dock at my boat launch is rubber and aluminum.

 

Comments?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share


Supporting Members

Supporting Members can create Clubs, photo Galleries, don't see ads and make messing-about.com possible! Become a Supporting Member - only $12 for the next year. Pay by PayPal or credit card.




×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.