cutwater and transom 'straps'

Andy Garrett · **Posted:** Mon Sep 06, 2010 7:05 pm

I like the look of a cutwater and transom strap. It really dresses things up a bit, but how are they attached securly and more importantly, without risking leaks?

Next question: What is the best procedure to fab these parts for a Zip?

DaveLott · **Posted:** Mon Sep 06, 2010 7:16 pm

Andy - I cannot help you on the fabrication. I have to learn how to do some metal work. So I had Cutwaters by Mike make mine

The traditional cutwater and transom band in screwed on with #6 screws on 2" centers only 1/2" from the edge. I set my screws, removed them, filled the void with sealant and reset the screw. No problem. I used only 3/4" screws so they do not penetrate the hull.

A number of guys are far more talented than I and built their own. They will chime in shortly

dave

Andy Garrett · **Posted:** Mon Sep 06, 2010 11:28 pm

I must be missing something.

If the hull planking is 1/4" or so on most boats, how does a 3/4" screw not penetrate the hull?

Lowka53 · **Posted:** Tue Sep 07, 2010 12:02 am

Daves boat is built up with about 3 layers of wood if not more correct me if i am wrong dave you should look at his build page

vupilot · **Posted:** Tue Sep 07, 2010 5:02 am

On the 1/4" ply hulls you will have to add backing blocks so the screw doesnt penetrate both layers. That and the sealant should keep things dry.

Bob Perkins · **Posted:** Tue Sep 07, 2010 6:45 am

I used shorter screws. the heads poked through a tiny bit, but I dipped them in varnish as a sealer. Never a drip from any of them.

Oyster · **Posted:** Tue Sep 07, 2010 6:57 am

sorta kinda small bit of diversion here that hopefully may create some thought or some tomatoes too..... :wink:

The real question should be are you using fasteners to hold the cutwater in place or fasteners to seat the cutwater until the modern bedding compound skins over, bonds and cures. There is surely a two edged sword on using certain bedding compounds though. I am not sure if applying a cutwater using fasteners with 2" centers these days is really the way to go, IMO. In the days gone by constant maintainance past a freshen up was involved with finishes only, being varnish on hulls solid planked boats. This does not really apply these days. While you do not want to use any 5200 type beddings, there are numerous compounds out there that will allow you to use less fasteners run into your wooden hull no matter the thicknesses.

Fasteners that are snugly tightened up truely only has a tiny bit of bedding in which to seal the exposed hole, which overtime has proven that water will find its way. So what have you accomplished with too many fasteners with modern day beddings, IMHO you have done little with a properly fitting cutwater and added more potential pitfall holes.
One of the reasons I posted this is that I personally installed a metal plate across the stem on my new boat to protect the stem from wear or compression dents from the roller on the winch stand and used no fasteners and over the course of four months now with numeous launchings and reloading and towing, its as good as the first day I installed it too. This has caused me to rethink my position of too many fasteners once again..

Iggy · **Posted:** Tue Sep 07, 2010 8:16 am

Sorta off topic.. but close to it.. why not use a sealant and skip the screws entirely.

Surely there is a way to clamp/strap/hold the cutwater in place till the sealant cures enough to hold it firm?

Has anyone done this.. and if so.. what kind of sealant did you use?

Oyster · **Posted:** Tue Sep 07, 2010 8:32 am

In my personal observation Iggy is that the weight is such that you would have prep the surface and use some pretty substantial compounds if I was to allow the bedding to be the only material long term in a boat application. With just bedding and some fasteners spaced a bit further, leaving a clear coat finish underneath will allow removal without disturbing wood if you use afhesive strong enough to exclusively. I attempt to think longterm in regards to maintainance.

billy c · **Posted:** Tue Sep 07, 2010 1:48 pm

i agree the fewer holes you have to drill into the hull the better and sealant applied to the screw holes will sooner or later fail.
-if you are going for the traditional look on the cutwater and transom band, there is little choice but to line the perimeter with screws. (plus it does take some persuasion to get a metal cutwater to conform to the shape of the bow)
although an extra few steps, you might consider what i did...
installed the cutwater and transom bands removed the screws drilled oversize holes filled with epoxy redrilled then remounted the cutwater.

Andy Garrett · **Posted:** Tue Sep 07, 2010 3:04 pm

Perhaps I will use a mastik (sp) as I would a skeg or spray rail, with far fewer screws. Say..., top center and bottom. Then remove and drill the rest of the holes in order to instal faux screw heads securely fastened in an appropriate fashion (soldered from the rear perhaps).

With this set-up, I get the traditional look without all the holes while still having a secure piece of trim.

DaveLott · **Posted:** Tue Sep 07, 2010 5:27 pm

Lowka53 wrote:

:lol: Daves boat is built up with about 3 layers of wood if not more correct me if i am wrong dave you should look at his build page

almost Rod. I actually have 3 layers of laminations plus one layer of veneeer. Chris probably did it the best way if only one layer of ply is present.

I filled my holes with polysulfide and reset the screws.

fergal butler · **Posted:** Wed Sep 08, 2010 12:12 am

I was hoping to have these made for my crackerbox and was thinking of making a fiberglass mould of the bow and the sides of the transom then make a male mould to bring to the fabricators for them to build off, will this work ( it will in my head) :lol:

DaveLott · **Posted:** Wed Sep 08, 2010 3:22 am

You will not need to got to that extent for the transom bands. Make yourself a cardboard template of you what for the transom band. They will cut it and then you just bend it to fit the curvature the hull.

Now for the bow. If you have the time and desire to build a mold, that would be a good thing. I cut cardboard templates and a template of the rake both male and female versions. Mike was able to do a pretty good job with that. Vupilot took his boat directly to the shop and Mike built using the boat as the template. The more the shop has to work with the better in order to get a good fit.

I learned something about the cutwater. Apparently during the welding process of the two sides the arc of the cutwater will open up due to the heat of the weld. So if a shop welds directly from the template you will have a flatter curve than your boat by one to two inches. This happened to me. The shop has to cut a few 1/8" cuts in the outer edge of the template and tighten the curve a little before cutting the metal and then welding. The pull of the heat will open the curve back up to the proper radius. We did not account for this on my first cutwater and it opened up by 2 inches although the tacked together sides fit perfectly. Once fully welded the radius opened up. On the second try we compensated too much and the radius did not open enough. On the third try we used the male and female templates of the rake for a guides and this time it worked like a charm.

So you might want to give your welder a heads up on that issue.

I am jealous of guys who can weld and fabricate. Told the Admiral that it would be good thing for me to go to the local tech school and take a class or two. You never know when that skill will come handy.

Glen-L.com

cutwater and transom 'straps'

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