First Time Builder Question: attaching gunwales

[algale]

Hello, I'm a first time builder who has been lurking here a while but now could use some advice.

The background is that I am building a Gilpatrick 16 foot Wabnaki cedar strip canoe, shown in the attached photo (I've since fiberglassed the outer hull). I'm getting ready to flip the hull and thinking ahead about the gunwales and how to attach them.

The design calls for solid 3/4 x 3/4 inner and outer gunwales attached by countersunk # 8 1 1/2 inch flathead wood screws only (no epoxy). My math may not be that great, but with two 3/4 inch gunwales separated by a 1/4 thick hull, I'm afraid those 1 1/2 screws may come right through once they are countersunk (especially since I'd like to sink the heads deep enough to cover the exposed heads with some wood plugs in a contrasting color (the gunwales will be Sapele and I'm thinking about maple for the plugs).

Specific questions I have:

Is it ok to attach gunwales with screws only (no epoxy)?

Is there any harm in going with a shorter screw to accommodate a deeper countersink to accommodate plugging the screw holes?

Can anyone recommends a quality countersink that will drill and countersink in one step and leave say a flat sided hole to accept the plugs?

Sorry if these questions are too basic; as I said, this is my first build and this is all new to me.

Al

 

[Denise MsWdnBoat]

Glue only will break off because they would be glued to the "skin" not mechanically to each other.

Make up some scrap 3/4 X 3/4 with 1/4" in between and set the bit to give you get the "just right" depth and depth of plug. I stopped using bungs (plugs) on W/c boats rails since they need to come off now and then. You can alternate in and out with the screws too. 1-1/4" may work. I don't know of any Counter sink that's flat.. guess you could drill with a fortsner bit and stop collar, then the drill hole for the screw (with a stop also) You could try the step bit that Kreg makes for pocket screws too.

Making rails is fun! I liked making the scuppered type

 

[Jim Dodd]

First I'd like to welcome you to the site !

The great thing about building a canoe, you can build it the way YOU want ! It's your boat !

That goes for attaching gunnels !
My personal method is to glue and screw my inwhale, and glue the outwhale. Here's my reasoning. I find that using screws only, allows moister to get between the hull and the gunnels, and rot is soon to come. By screwing the inwhales, I'm comfortable that I can hang my seats, and support my weight from the inwhale ! The glue adds strength, and seals out water ! I have canoes built in the early 90s that are slightly weathered, but not rotted. Seal you gunnels one way or another !
With my method, no screws are visible. Thus no place for water to enter the wood. No plugs needed.

I cut my inwhale 3/8" then I add 3/8" spacers. This equals 3/4". I have open spaces, scuppers that allow attaching rope, and draining water from the hull.
I will post some pics.

Jim

 

[Todd Bradshaw]

Personally, I never glue gunwales to boats. I've had to repair or replace enough of them over the years to know better. I do put a little bit of calk in the screw holes and have never had a screw area rot out. You can certainly shorten your screws a bit and sink them deeper. For countersinking, you want a Fuller countersink/counterbore in the size of the screws you are using (likely #8 or #10 FHWS). They are drastically better than your typical countersink bit and they make matching plug cutters. Plugs are easy to remove later in a few seconds with a drill if it is ever needed, so don't worry about that. Brass screws truly suck (which you'll see when the heads start wringing off). It is well worth the effort to get silicone bronze screws from a marine retailer.

 

[Jim Dodd]

I use the tapered bit countersinks as Todd pictured and described.

Funny about replacing Gunnels, the only ones I've replaced are the ones that were NOT glued ! Again unless you can seal out moisture, and it comes in from screws and between the hull and the gunnels, they will rot in shorter order!

Replaced a set of gunnels for a friend's Bell tandem, last year. They were 6 or 7 yrs old. Easy enough to replace, but rotten before their time. They were on a Royalex hull, and were not well cared for

You are the builder, you make the choice !

Jim

 

[algale]

Many thanks for the thoughtful responses. I see there are different schools of thought and there are advantages and disadvantages whichever way I go.

 

[pklonowski]

I have yet to see a mass-produced canoe, with wood gunnels, that has any finish on the gunnel surface that abuts the hull. If that surface was coated with ANY finish, these would fare better than they do. On my wood gunnel boats, I put a coat of oil, let it dry, then follow up with several coats of varnish, even in the screw holes. Yes, it's extra work... but it's less work later on.

 

[Todd Bradshaw]

Yep, much of the canoe industry seems to think that if you can't see a piece of raw wood because it's up against something, it will never weather or rot. Wrong. In the real world of wooden boatbuilding that is not an acceptable practice and the only reason it works on canoes at all is because most don't ever see that much weather. Being your own builder, you have the opportunity to fix those issues from the start, whether with glue or with bedding compound or sealer. Either can work, it's just a question of whether or not you think you might ever need to remove the piece for repair, refinishing or replacement. In terms of the strength of the attachment, I have never really noticed any difference in the different methods. Gunwales falling off of canoes doesn't seem to be a common problem if they aren't rotten.

 

[algale]

Gilpatrick's book, which I am generally following, suggests sealing the gunwales with epoxy before attaching, presumably to prevent rot. What is "bedding compound"?

 

[Todd Bradshaw]

Bedding compound is a thick paste or almost clay-like traditional goo made from oils and natural fillers. Hardware store plumbers putty is pretty similar, but usually a bit thicker. Before fastening a piece of wood down, you butter it with bedding compound. As you screw it into place the excess gets squeezed out and any space in the joint is filled with compound. This keeps water out of the joint, or from soaking into the wood. Some brands are kind of sticky/gooey, but it's just a sealer, not really intended to be an adhesive. It varies in durability, depending on what it is and who made it, but it can often last for several decades and still be perfectly good and functional when you disassemble an old boat. On canoes, it might be used for lapping canvas and bedding parts like keels and outwales up against the hull.

One of the more popular brands.

http://www.jamestowndistributors.co...rd=dolfinite&gclid=CPPoqoOwz8UCFQuFaQodWxoAiw

 

[Rod Tait (Orca Boats)]

I agree with Todd. I have replaced too many gunwales that were not sealed properly before putting them on or were neglected and mostly rotted from the inside out. I seal with epoxy on all sides before installing with bronze screws and then seal all holes with varnish (simply dip your screw into varnish before setting). And then there are those who fix things for a quick sale and use steel screws (have even seen drywall screws) which will turn the wood black in pretty short order. If you are going to do it, do it right and use marine products like bronze, bedding compounds, marine paints and varnishes. Just replaced a keel in which someone used household silicone to seal. AARG. Do you know how hard that was to get off a perfectly good keel. Sorry , just needed to get that out of my system.

 

[Pantry3cow]

So Rod you say not to use stainless screws, really why black marks? Good thing I got on here before I fastened my gunwales. I’ve had a hell of a time getting them on bent and fit on the wee too at first. I’ve since went and got a pc. Of 2”abs filled it with hot tap water then put the gunwales in for 30 mins. Then clamped in place while wet. I then let dry for a day or 2. This helped more then I could imagine. My plan was to just glue on, but after reading these posts my plan would be to screw right through fill the holes with a filler. I will apply 2coats of resin on all 4 sides before I fasten them on. Many thanks to all here for the shared knowledge

 

[Jim Dodd]

We all have our preferences !

I glue and screw my decks, and inwhales , and glue my Outwhales on.
The epoxy seals out moisture, I have been building since 1990. I have yet to NEED to replace any of the gunnels on the my 25+ hulls, I've built.

I know ! The question is how do you get the gunnels off if you need to replace ? I'll let you know if I ever see the need !

Most people that have to replace their gunnels, leave their canoes out in the elements ! I don't. They are stored in unheat garages or sheds.

Now How would I replace My gunnels? They would be rotten enough that a chisel would easily remove the outwhale, as well as the inwhale !

Jim

 

[Dan Lindberg]

Stripper builders like to glue rails on,
W/C builders like to screw rails on, due to being easily removable.

I glued my 1st 2, and regretted it as I wanted to make some changes.
After being bitten by W/C, these days I'd screw them on.

If you break a rail, it's hard to replace when glued on.

Your choice.

Dan

 

[Jim Dodd]

If you don't glue your gunnels on, epoxy coat the side against the hull. At the very least, two coats. Screw them on.
I liberally coated my gunnels with Watco Teak. They take a lot of abuse, and don't show scratches like varnish (urethane, Poly or Spar)

Jim

 

[Pantry3cow]

Ok i’ve decided to glue on my inwales. Due to a bulkhead I want to put in. I have it all clamped on one side only. How long should I let the resin cure before removing the clamps?

 

[Jim Dodd]

I feel the minimum is two days. Any thing with tension on it ( clamping pressure)
Longer is my personal preference.

Note that the epoxy is filled with Cabosil, and ground glass. I always add very fine sawdust from my ROS, for color, though it isn't apparent in this pic.
Also note that my Outwhale Caps the hull ! This seals out moisture from getting inbetween the two layers of glass. The outwhale starts out at 5/8" thick. A 1/4" is removed to compensate for the hull thickness..

In this pic, you are looking at the gunnels, from inside the canoe. Note ! I round over the inwhale and outwhale Before attaching to the hull. I don't rouite the inwhale, in the area that my seats are hung, or the thwarts are attached. I finish these later by hand for a better appearance to me anyway !

Inwhale glued and screwed

This pic shows how to clamp the ends of the outwhales, so No screws are showing on the outwhale ! A screwless appearance is what I like !

The Dragon's Teeth ! Keeps the clamps from sliding off the end of the canoe.

Jim

 

[Canoeal]

My inwales are routed first, then epoxied. My outwales are just epoxied ....

 

[Jim Dodd]

Tried routing scuppers ONCE ! Poor quality bit, and operator error, ruined a set ! I now glue spacers, and haven't ruined a set since !

Jim

 

[Canoeal]

I assume you are referring to chip-outs. In order to avoid those I cut with a fine tooth jap saw (26 TPI to the depth of the section I want to take out, one each side if the scupper. Takes a little bit of time, but Wella! No more chipping. Two piece gunnels are much nicer to look at than all the blocks.