Gunwale advice needed

[John Turpin]

Tomorrow, I'll be starting on my Lapwing's foredeck, sidedecks and gunwales and I'd like to get some quick advice from ya'll.  (Note:  "Ya'll" is a regional colloquialism that can be defined as "this group" or "you all" or "thee".  For you northern folks, don't let this frighten you.)

I bought some "African mahogany" (unknown species) that I plan to use for this.  I'd envisioned laminating the gunwale out of three 3/16" or 1/4" strips of 1" wide mahogany--whatever thickness enables it to bend without drama.  But, I'm not sure how to make this overlap the top edge of the deck.  I guess I could make a tiny fourth strip that would lie atop the deck and be laminated to the "side-mounted" strips.  Or, I could try to make some kind of molded mahogany piece that could be bent into place that covers both the shear strake and the edge of the deck--sort of an upside down L.  Or, I guess I could just try to cut a curved cap piece that would lie atop the deck edge and laminated strips, but I'm pretty sure that I don't have wide enough mahogany for a big curved piece like that.  The plans just show a solid gunwale member that doesn't overlap the deck joint, but I'm not sure that this mahogany will bend without laminating it in strips.

Any tips on how I might approach this?  What did ya'll do?  :wink:

Thanks

[Hirilonde]

African Mahoganies should work quite well for this application.  They are most used as planking because of the very resilient  stringy grain.  But this characteristic is a good one for gunwales as well.  You will find that it doesn't always mill as smoothly as you might wish.  It has a tendency to tear when planing.  Really sharp tools help, (duh, how profound a statement).  You may have to do a lot of sanding, (sheesh, as if you have done enough yet).  The main thing to look out for is grain run out.  This can be rather dramatic in some boards.

But once you have determined that the pieces you have are suitable, I bet you find that 1/4" strips take the curve quite well. 

Overlap the top edge of the deck?  I am not sure what that means.  The outboard edge of the deck as in the edge of the plywood?  I definitely think it should overlap that edge of the deck.  This way you are protecting the plywood from physical and water damage.  I think it should end up flush as well so as not to inhibit water running off the deck.  Some think that seeing the laminates that make up the gunwale does not look good and choose to cover that up.  If the glue joints are tight this doesn't bother me at all and I don't think the effort is worth it.  This detail is a matter of preference and doesn't do anything practical really.

Varnished African Mahogany looks great in my opinion.  It will contrast a bit with the okoume plywood, but that isn't necessarily bad.  Just do this detail as well as the rest of the boat and it will be beauteous.

[Dale Niemann]

John,

I have attached a couple of thumbnail shots of "Lively".  Hopefully, they show the deck gunwale detail.  I followed the plans and left the plywood end open and put the gunwale on the topsides.  The white line allows the wales to be removed and replaced if it ever becomes necessary.

As you can see, I used mahogany and it is laminated.  I got the wood from a friend that was restoring a Chris Craft.  It is about 5/16 or so thick.

Lively has been around since 06 and I have had no problems with this solution.  In fact I really like the toe rails on the deck.  They really come in handy when reefing the main sail.  They are also laminated.

If these photos do not work, send me an email and I will send you the full size version.

Dale

[Greg Luckett]

John, on my Spindrift 12 I used white oak strips, about 1/4 x 2 then capped them with some scrap Okume 6mm. Then I rounded off using a router. It came out looking very nice....at least I think it did.

[John Turpin]

Thanks everyone.  That's what I work on this weekend.

[Wile E. Coyote]

Hi,

 

Do you laminate the gunwales flat and then bend them onto the hull in one piece, or do you attach the 1/4" strips one at a time?

 

Thanks,

 

Matt

[Lynn Watson]

You laminate them in place on the hull; thin strips bend much more easily than thick ones and decent (i.e. hard) gunwale stock is tough to bend around those curves. The trick seems to be holding the strips still when they're all spooged up and slippery. Others on the forum have worked this out well.

 

Also, it's best to fit both sides at the same time so the springy laminations on one side don't push the boat out of shape.

 

Lynn

[Wile E. Coyote]

Thanks Lynn.

[Wile E. Coyote]

Ok, at the risk of exposing myself as a little simple, I still haven't grasped the concept of installing the laminated gunwale. 

 

Do you butter up all three strips and then wrestle the whole thing onto the boat at the same time?  That sounds quite challenging.  Or do you put one on at a time, wait for it to cure and then put the next one on?  This sounds easier, but from what I can see in pictures and construction threads it doesn't look like that is how people do it.

 

I think this is probably simpler than I'm making it, but I'm just not getting right now.  Any help appreciated!

 

Thanks,

 

Matt

[Chick Ludwig]

I'd butter them all up together. Here is a tip on how you can make it easier to finish the laminated gunnel. Lay masking, or better yet, wrapping tape along under where you are laminating the gunnel. This will keep your stack of laminations from sticking to the boat. When cured, remove the gunnel, pull off the tape, clean it up (gunnel), radius corners, etc, and then epoxy it on permanently. Keeping the strips from sliding around can be a challenge. Once you get them buttered, stacked, and clamped in place, you could go along evening it up and hammer in some nails  to hold it. ( I use air nailers for everything. They set the nails below the surface so you can fill over them. Just leave them in place, they won't hurt a thing. Be sure that they don't go into the boat.) But maybe just making sure that they are aligned as best you can without nails is best---be patient. (Ha! I never am...) By-the-way, I make the strips a little wide so that I can finish them down to the correct width.

[tom151]

Ok, at the risk of exposing myself as a little simple, I still haven't grasped the concept of installing the laminated gunwale. 

 

Do you butter up all three strips and then wrestle the whole thing onto the boat at the same time?  That sounds quite challenging.  Or do you put one on at a time, wait for it to cure and then put the next one on?  This sounds easier, but from what I can see in pictures and construction threads it doesn't look like that is how people do it.

 

I think this is probably simpler than I'm making it, but I'm just not getting right now.  Any help appreciated!

 

Not in any order...

 

For sheer strips, gunwales, rub rails, etc you will discover that in many cases they are actually bent/curved in two dimensions -- which can be a surprise you if you're not ready for it.

 

For boats with lots of sheer curve (in profile view) it can be very difficult to laminate the beam in advance of attaching it to the boat and have any hope of getting it properly/easily fit to the hull. I tend to choose to do each lamination individually - directly onto the boat. And yes, as mentioned in a post above, do both sides at the same time.

 

Adding these features after the deck is on can be difficult clamping and result in needing to use (temporary) screws to clamp up the laminate.

 

If it will also serve as a rub rail I prefer to laminate it (and making the outer laminate in shorter, scarfed sections as well. For me it's easier to do repairs to  laminated rub-rails - mostly because using the various pieces minimizes the damage spreading along the full length of the grain run.

 

Lastly, IMNSHO, a builder should take every opportunity to cover the end grain of plywood with timber. The vulnerable uncapped end grain of ply tends to be the single most likely source of unnoticed damage and water intrusion - with the subsequent rot. Consider this when you decide on adding your rails.

 

The obvious assumption here is that you've not decided that the boat is essentially disposable and expect it to last long enough pay you back for the good work you've done.

[Chick Ludwig]

I did forget about not being able to clamp in way of the deck. I agree with temporary screws. When re-installing them, I would countersink and plug the holes. We all have different opinions on how to do things. That's one of the great things about this forum. Lots of good ideas and advice.

[PAR]

I covered the end grain of the deck with the rub rail. I hook scarfed oak to length, after tapering the ends a tad and bent it around, with little difficulty. I planned for this before painting, so I used temporary blocks screwed to the topside planks to hold the clamps. This also permitted me to drill and screw the rub from the inside of the boat, through the inwale, into the rub. I did place a screw at each end on the outside, as it was too difficult to get in these spaces (for future removal and rebedding) once the deck was installed. I spaced them on approximately 16" centers. I also hid the rub/hull seam, with a mahogany covering board and toe rail, so water can't trickle in from above. This left a clean, no screw appearance for the rub. If you have the deck on and she's painted, you'll probably have to screw to the sheer clamp (inwale) through the rub rail, from the outside. This is perfectly acceptable and pretty common, I just like the clean look.

 

 

My rub strip started as a 4/4ths by 1.5" piece, before shaping and tapering and bending the oak wasn't difficult, but oak likes to bend, unlike mahogany, which likes to break. Use plenty of heat to bend the mahogany and start at the bow and work aft, so the leverage of the rub can work for you. You could also dowel it, instead of screws, which if mahogany, grain matched, will all but disappear when finished. If you do use dowels, angle every other one opposite from the previous, so it'll hold good.

 

There's lots of ways to skin this puppy, just think about it and maybe try a few different techniques as a dry run to see if you can easily bend the stock. The sheer isn't very severe on your boat, so all should go well. A laminate will bend easier, simply because of the smaller pieces, but it's not as necessary as you might think, considering the curves involved.