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I'm building a Cartopper and -- knock on wood -- my fiberglass and epoxy butt joints seem to be good. My question is if I want to use a wooden butt joint in the future, how does one do so?

Thanks,
Dan

Hi Dan,

Here's how I implemented buttstraps on the Teals sides...

1.) Cut out four ply buttstraps, 3/8" x 4" x 16" (of course, sizes vary per boat)
2.) Drew the longitudinal center line on the buttstraps including the ends
3.) Put panels on scrap since the nails being used will pass thru the straps and panels
4.) Placed the buttstraps on the seam where the panes meet (obviously, take into account frames and other panels)
5.) Carefully aligned the center of the buttstrap with the seam
6.) Temporarily tacked a straight piece of scrap to act as a fence to keep the buttstrap in place during the gluing and nailing (otherwise the buttstrap will slide every which way!)
7.) Slathered the buttstrap with glue (I pre-soaked with epoxy, then used thickened epoxy as the glue... Weldwood works too)
8.) Made sure everything was lined up and the joint of the two panels being joined was tight, then used smooth copper nails to secure the buttstrap and the panels... the nails have to be copper and they have to stick out the side of the panels... in the case of 3/8" ply, 1" nails are used...
8.) I pried the panels off the backing scrap and then placed a nail set against the side of the protruding nails and bent them over to form a small "U" pointed in the direction of the ply grain
9.) Next, place the head of a sledge hammer against the head of the nail and drive the "U" into the side of the panel with the grain (this is called "clinching")... with practice you can slightly sink both the head and the "U"
10.) Remove fence scrap
11.) Clean up and set aside and let fully dry

Dynamite talks about this in his book "Instant Boats"...

Hope this helps...

Alan

Alan,

Sorry about the delayed thank you for your detailed instructions on how to make a butt strap. I just read it.

I wanted to know how to do a butt strap in case my epoxy/tape joints didn't work out and needed to go to a plan 'B'. So far so good, at least with the butt joints.

I've been running into some problems due to my lack of woodworking experience but persevering nonetheless. My cartopper will be an inch-and-a-half shorter due to my incorrect beveling of the transom sides. Oops. I hope that doesn't throw everything else off.

Dan

Hi Dan,

A couple of thoughts...

* First, I assume that the incorrect transom side bevels are too severe and that is forcing too sharp a bend in the sides and that shortens the boat... Here's my $.02 (and it's probably over-priced at that...) Get the boat into the shape designed. You can always glue (with thickened epoxy) strips of wood to the existing transom bevels and re-bevel to the correct angle. If push comes to shove you can leave the bevels as is, and build per the plans and then fill later. But if you end up building the boat too short, you can have problems with how the panels go together, where the sail's center of effort falls, etc. I'm not saying that that is what will happen, but for me it would be a concern.

* When it comes to butt joints, fiberglass butt joints, epoxy, and in general all things unknown, the best advice I can offer is to practice on scrap first. I cannot tell you how much money and time I've wasted because I jumped into a build without knowing what I was doing.

Alan

Alan,

The bevel I cut into the transom to accept the side panels is shallower than it should be, making those side panels diverge enough from the fair curve that allows them to sit flush with the transom sides.

Unfortunately, I glued and nailed the first side panel to the transom before checking that both panels would sit flush. I did not discover my mistake until getting ready to glue and nail the second side panel to the transom. I was dismayed that it wouldn't fit properly and then double checked that the panels were the same -- they were -- and that the frames were in the proper spots -- they were. That's when I checked the bevel angle that I cut into the transom with the bevel angle shown on the plans. I don't how I screwed it up, but I did.

So I decided to glue and nail the second panel on anyway and then carefully squeeze the 'c' frame into place. Well, that worked out, but I am having second thoughts about that solution because, even though it has held and seems okay, I am thinking that when I put the bilge panels on those panels won't mate properly with the side panels when they get closer to the transom.

My thought now is to cut the transom off the side panels, re-beveling the transom sides, and re-attaching the transom to the now shorter (by an inch-and-a-half) side panels.

Does this make any sense?

Dan

Hi Dan,

Thoughts...

I've been worrying over your situation... Looks like you have three options...
i.) Quit. Bad idea in my book.
ii.) Go forth with the shorter build and adjust... May work... may not... To create the new bilge panels, you may have to use battens and building paper to make things fit... Not ideal in my book either.
iii.) Fix the transom angles and create new side panels from the existing with new butt blocks or scarfs, etc...

IMHO... IMHO... IMHO... Hit the "moaning chair" and then figure out what it will take to get the hull as designed.

But no matter what, measure for the umpteenth time and find out exactly what is right and what is wrong...

At this point, pics would help... Feel free to post so we can get a better feel for what's happening...

Keep the faith... We'll figure this out...

Alan

Dan, the only problem you would need to address is the transom dimensions, if you move the transom forward 1.5".
The difference shouldn't be much but it will be there for each edge of the transom - sides, bilge panels, and floor panel edges. Use the plans to pull off the adjusted measurements. Or use the old triangle math to do it. Remember to account for the fact that the different panels lay on different planes.

OR do it the epoxy way. Use a temp transom frame to hold the side panels, mount the bilge panels and floor, use the stitch part of stitch-n-glue to position the side, bilge and floor panels properly, place your old transom into the proper position and bed with epoxy wood putty. Let cure and theres your new, properly beveled transom - bevels courtesy of epoxy.

Looking at dhansen's beautiful Cartopper pics, I see a skeg too. That would also be shortened 1.5" I'm guessing, if it runs out to the transom. Bilge panels and the rest will also have to be trimmed, but that should be relatively easy.

My ideas. Like any internet solution, worth what you paid for it!

Sorry to hear that you're having problems with your build. I really don't think it's all that big of a problem from what you've said? The side bevels on the transom are supposed to be 18 deg. and you made them a little less than that, if I understand you correctly. You were able to fit the "C" frame into it's proper position. How much was the bevel angle off? It really can't be very much can it? Since the transom dimensions are given to the inside of the transom framing the bilge panels should still fit. I would try making a test bilge panel from cardboard to see how it fits. You would need only to make this test panel about 4 feet long to test it's fit from frame "C" to the transom. You can temporarily install a stretcher between the bilge panles to better push them into correct alignment. I would also temporarily clamp gunwales to the upper edge of the side panels to pull them into proper alignment. You will probably have only a slight kink in the sides, just forward of the transom. Take a look at this and decide before you do any major reconstruction or cutting.

Hello,

Thanks for your input on my problem, though I hope after looking at the three photos linked to below you may not think it is much of a problem. I hope they give you a reasonable perspective.

The only pieces that are permanently attached now are the sides to the transom. The sides are tacked into the "B" frame and just laying against the "C" frame.

I think I am about five degrees too shallow on the transom's side bevel, but that's enough to throw a very slight reverse camber into the sides near where they attach to the frames.

Well, a word is worth a thousand pictures:

Dan

http://picasaweb.google.com/lh/photo/iG ... directlink
http://picasaweb.google.com/lh/photo/DL ... directlink
http://picasaweb.google.com/lh/photo/UV ... directlink

Hi Dan,

A few thoughts...

* Right now, things don't look so bad... You may be able to put on a false stem and go from there... Don't know what will happen down the road...

* If the only secure joints are those joining the side panels to the transom, I'd take a sawzall and cut right through the glue joints, free the transom, and get things right. (Jeez... You'd think I have some experience with wood butchery...)

Alan

Please, befroe you cut your boat apart, try a trial clamping of the gunwales in place, as I mentioned earlier. Also see if the bilge panels will push the sides into alignment. We've had many boats on this site build with bevels cut much worse than this. Try and see if everything won't pull into position befoe you cut things apart. I'm betting that at most a little "body putty" is all that will be required to correct the slight hollow that will result when everything is clamped and pulled into position.
Of course, if you want to start cutting, I'd advise a hacksaw blade with a pull handle. It will cut through the nails, take out a very small kerf and allow you to take your time so that the cut doesn't go too far astray. You'll probably need to use a demolition blade in a circular saw to recut the bevels on the transom sides after everything is apart. Clamp a straight edge to the transom to guide your saw, as with little to cut, it will want to wander. You'll also need to grind or sand off any wood and glue that's left attached to the plywood. One of the problems is that all of this cutting might well result in something worse than what you have now.

My main concern is the current shortening of the boat... As I'm a poor sailor, I can't really speak to this... For all you serious sailors out there, here's my question... "What happens when a small boat is inadvertently shortened by 1.5 inches?"

Alan

As Paul suggests, I think I will try a clamping of all the panels first. If that produces a proper enough seam, then that's the way I'll probably go. I'll get to it this weekened and keep you posted.

I do appreciate your help with this...adventure.

Dan

Well folks,

After almost a three-month layoff from any boat building activity (extreme cold and tons of snow blocking my garage) I am back at it. I successfully cut the side panels and transom apart, re-beveled the transom, and re-attached those parts. It may not turn out to be a work of art, but I am committed to get this finished by June.

I'll keep you posted.

Dan

Hi Dan,

Great to hear that you're at it again...

Thoughts...

* The reason I mentioned cutting the boat to get her into the proper shape is because that was the advice Dynamite gave to a builder when he had messed up a frame. He literally had the builder cut the boat in half... Believe it or not, it's not that big of a deal. Frightening? Yes. But also doable as Dynamite wrote.
* In my book, water doesn't know what you did to get the correct shape as designed. They (wind and waves) only know if the shape is correct as Phil Bolger designed it.
* As for appearance... I always take the attitude of "function over form". (But that's just me.) My rule is this - if you find my boat ugly, then I'll just leave you on the shore... Everything I build (furniture and boats) are brutally strong and built to function as designed. Especially when it comes to boats, I just don't know enough to work with an altered design... Maybe it will work... Maybe it won't. I'll leave that decision to others far more knowledgeable than I to make those calls.
* IMHO, I think you made the right decision... Get the job done right.
* As for the final appearance... By the time you get done with the fiberglass and paint, I'll bet she'll be a beauty.

Thanks for the update and keep us posted...

Alan