Moccasin 12

[Hirilonde]

 Use a bevel gauge to determine the actual angle for your boat.  

Yup, I use a sliding bevel gauge for many things.  I don't even bother to figure out what the actual angle is.  It doesn't matter so long as the piece matches where it fits.

[slaterturf]

Thanks for the info and tips.  I have fit the breasthooks, the gunwales, and the inwales.  After reviewing the plans it seems to me that I now need to fit and glue the doubler into its place.  The plans refer to four parts of the doubler, however I cut mine out as one piece.  I presume my plans show it as one piece because I am building the 12 foot model, while the larger model doubler must be in four parts.  It also looks to me that I don't yet glue in the breasthooks and wales until I have the doubler in place and secured. Once that is done then I would install the temporary prop to help shape the hull properly.  At that point I would glue in the breasthooks and the wales.  From there I would tape and glue the outside seams, then come around to the inside to fillet, tape, and glue the interior seams.  

Any thoughts, comments, and guidance are appreciated.  Thanks.

[John Burritt]

I'd glue the gunwales/inwales & breasthooks before I did the doubler.  Also pull the beam to the proper width.  This pull the boat into the proper shape.  Then fit the doubler, forcing it against the bottom to maintain that shape.  You need to bridge across the gunwales so that the temporary props hold the doubler in place while the epoxy sets.  Support the hull at each end beyond where the doubler fits so you don't set a flat spot in the hull.

Fillet & tape the inside seams before you do the outside.  The outside of the bottom/side joint needs to be rounded & faired before it is taped.  You can't do this before the seam ties are removed.  Ties can't come out until the seams are secure on the inside.

[slaterturf]

That is helpful.  I have a cross piece to the designated beam width secured on to of the gunwale to hold the boat to its beam.  I could see a few different directions to go and began wondering which road to take.  The plans provide good guidance as to setting up to install and glue in the doubler.  Thanks.

[slaterturf]

Well, I am back to the next step.  Sorry I have not posted any photos.  I have the gunwales, inwales, and breasthooks in place.  Next is the doubler.  As I try to fit the doubler into position, I find it does not quite fit.  I am shaving off the sides a little, but am wondering how far to go with shaving.  As the doubler bends with the curve of the bottom of the boat it seems to fit better, but then the edges are up against the plastic ties.  I was reading some of the previous posts and it seems I should wait to tape and glue the edges until after the doubler is in.  Does it matter how close the doubler edge is to the side of the boat?  Can I shave off enough of the edge of the doubler to fit inside the plastic ties at the chine?  Thanks for any tips.

[slaterturf]

I'd glue the gunwales/inwales & breasthooks before I did the doubler.  Also pull the beam to the proper width.  This pull the boat into the proper shape.  Then fit the doubler, forcing it against the bottom to maintain that shape.  You need to bridge across the gunwales so that the temporary props hold the doubler in place while the epoxy sets.  Support the hull at each end beyond where the doubler fits so you don't set a flat spot in the hull.

Fillet & tape the inside seams before you do the outside.  The outside of the bottom/side joint needs to be rounded & faired before it is taped.  You can't do this before the seam ties are removed.  Ties can't come out until the seams are secure on the inside.

So, when I fit the doubler into position, it will just clear the plastic ties at each side.  Then I would fillet and tape the inside seams, over the plastic ties. When this is done, I would pull the plastic ties out from the outside and fillet and tape the outside seams?? 

[John Burritt]

The doubler fitted to the bottom of the boat should just clear the ties on the side seams.  Glue the doubler in place.  Then put SMALL fillets between the ties - small enough that they won't interfere w/ the regular fillet & "between" so you don't glue the ties in..  Once these harden, the ties can be removed.  Then fillet and tape the inside seams.  Now you can either turn the boat over; round the outside of the seam; and tape it.  No filleting on the outside - just some thickened epoxy if you have some gaps to fill.  Actually, yuou can continue working on the inside of the boat and do the outside seams later.

[slaterturf]

The doubler fitted to the bottom of the boat should just clear the ties on the side seams.  Glue the doubler in place.  Then put SMALL fillets between the ties - small enough that they won't interfere w/ the regular fillet & "between" so you don't glue the ties in..  Once these harden, the ties can be removed.  Then fillet and tape the inside seams.  Now you can either turn the boat over; round the outside of the seam; and tape it.  No filleting on the outside - just some thickened epoxy if you have some gaps to fill.  Actually, you can continue working on the inside of the boat and do the outside seams later.

Thanks John.  I have been thinking this through this evening.  I trimmed the sides of the doubler and it is beginning to fit in nicely.  I think I need to trim the sides more so that they will clear the plastic ties.  It seems that I would install the doubler first? or do I tack the seams and come back for the doubler.  It looks as if the doubler will require a lot of epoxy.  As I install the doubler, I would wet out the wood on both the boat and on the bottom of the doubler with epoxy.  Then I would mix some thickened epoxy and come back to paint this on the floor of the boat and the bottom of the doubler.  At that point I would slide the doubler into place and secure it with the temporary prop and some other weights, curving it into shape and position.  I read in the plans to score the bottom side of the doubler with a sharp knife to improve the curvature of the doubler as it is pressed into position. It seems placing and gluing in the doubler will use a lot of epoxy.

[John Burritt]

Install the doubler before doing the side seams.  Locking up the side seams first would prevent the bottom from assuming the proper shape w/ the doubler.  Yes, installing the doubler uses a lot of epoxy.  As you say, 1st wet both surfaces (after you've scored the underside of the doubler).  You should be able to apply thickened epoxy only to one surface - I'd do the boat bottom - as long as you get a good reasonably thick even coat.  This time you're looking for "runny mayonnaise" rather than the "thick peanut butter" you use to make fillets.  Be sure the surface is well coated and you don't scrape it off when you put in the doubler.  Also be sure that the edges have squeeze-out ALL AROUND so you don't leave gaps where water could get underneath later.

[slaterturf]

[John Burritt]

The boat is looking good!  A question: Have you taped the inside of the seams after you filleted them?  If not, any of a variety of curved/rounded rasps or sanding devices can be used to smooth out the bumps.  If the seams are already taped, you may just have to live with the bumps.  Don't forget to fair the edges of the tape both inside and out w/ epoxy thickened w/ something like microballoons so they aren't as noticable when finished.  At least 2 - 3 coats of epoxy overall sanded smooth should give you the surface you want for painting. 

Typically, you need an epoxy primer as the barrier coat between the epoxy sealer and the finish paint.  Which one depends on the paint you choose.  Do some research on line re: the different types of paint - from old fashioned boat paint up to 2-part polyurethanes w/ a bunch in between.  Here its a matter of taste along w/ how durable and how "yacht-like" you want the boat to be.  (I did one w/ fire hydrant paint <"industrial red"> because that's the color the owner wanted.  Saw the boat several years later after it had been seriously neglected <owner died> and the paint still looked fine.)  Lot's of choices; do your research; follow the directions.

Do whatever you can to minimize your exposure to paint vapors.  Some just smell bad, but some of the really dangerous ones, like isocyanates in 2-part poly's, are odorless.

Keep up the good work.

[slaterturf]

John, Thank you very much. 

Actually, I have taped one end on the inside and not the other.  I have filleted the inside without the tape, but I think I will add more fillet to improve the roundness of the inside of the chine. 

I will study further on the paint. I will do my painting outside during good weather. Thanks.

[John Burritt]

ALL the fillet on the inside needs to be taped.  You need the strength of the tape strands running across the joint to spread the loads on the seam.  Saw some Opti prams awhile back where the inside seams weren't taped - just filleted.  The seams were failing rapidly, having to be repaired & taped.  If you add more fillet, sand the original well to get a good bond.  Then tape over the new fillet while its still wet to get a good bond there.

Painting outside is a good idea.  The trick is to minimize the "bug per sq. ft." quotient.

[slaterturf]

I am working on my canoe again.  I have to locate the spreaders and install them.  The spreaders should be 42.5 inches from the bow and from the stern.  The width to the outside of the gunwales should be 26.5 inches.  The problem I find is that I had used a spacer on the transverse center line to maintain the shape in the center to 26.5 inches wide.  I have glued and taped the interior.  The inwales and gunwales are in place and glued.  When I used a spreader to push the sides out at the 42.5 inch mark, the wood began responding with loud cracks and other noises, so I stopped that.

[John Burritt]

Do the plans call for 26.5" width at the center AND ALSO at the stringer locations?  Doesn't sound right.  Would make for a straight-sided center section - which it isn't.  I'll check w/ Graham tonight.  Looking at your pictures, the shape looks pretty good.

[slaterturf]

My interpretation of the plans were that at the center line I should have 26.5 inches.  I used a spacer to hold that width while I taped and glued the interior.  I have released the spacer and I now have 26.75 inches at the center, to the outside of the gunwale.

At 42.5 inches from the bow and stern I have a width to the outside of the gunwale of 22.75 inches.  I have smooth lines down the sides and a nice shape to the boat.  I had imagined the spacer I used would be replaced with a singular spreader in the middle.  Two problems came to light: 1) the spreader would be located right where I would sit, and 2) the plans call for two spreaders.  Then I realized the more sensible guidance of the plans ... two spreaders.  The plans say to locate the spreaders 42.5 inches from the bow, but that measurement is "not too critical". 

So, I will ease back into the canoe, off the bow and stern, and position the spreaders where they will be able encompass a single passenger within the middle of the boat.  It makes sense to me as I think about the stresses on the sides of the boat once there is weight sitting in the center of the boat.  The spreaders would help the shape of the boat remain, otherwise it would seem the boat would tend to fold up around the passenger once it is in the water.

This photo shows the canoe from above with the spacer installed to maintain the 26.5 inches at the center beam.

[slaterturf]

Ok, I figured it out ....  I think.  Thanks to the opportunity to talk it out through via this forum. 

The plans for the spreader are measured in inches as shown on the plan.  The plans show a half spreader measuring 11 inches.  The full spreader to the inside of the marine plywood, under the inwale, measures 22 inches, per the plans.  I have 21 inches at the 42.5 inch mark off the bow and stern!  Excellent.  When I come inboard from the bow and stern by 4.5 inches, I have a 22 inch breadth.  I will be able to make the spreaders according to the plan and position them under the inwales just a little further inboard than the "not to critical" 46.5 inches noted by the plan. 

I am not sure I really missed anything at this point other than my attention to detail.

Thanks John, for being a sounding board. 

[John Burritt]

Looking good.  Now would be a good time to glue butt blocks on the inside of the midship joints.

[slaterturf]

I am not clear about the butt blocks on the inside of the midship joints.  I don't see them referenced in the plans, nor did I notice them in the  photos sent on the disk.

Would I use a piece of the 4 mm plywood across the midjoint seam?  The height would be the same as the height of the side.  How wide?  The width of the fiberglass tape?  I can see that would add some strength to the seams.  Otherwise the only thing carrying the load as it comes to that point would be the fiberglass tape and epoxy.

Thanks.

[John Burritt]

I can't tell from the pictures - have you taped part of the mid-ship seams already?  If so, finish it to the bottom of the joint, and also tape the outside of the joint.  Alternatively, using a butt block on the inside eliminates the need to tape the outside, thus making fairing easier.  A good rule for the width of a butt block is 8 times the thickness of the plywood ON EACH SIDE of the joint.  (4 mm * 16 = 64 mm total width).