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Justin C

Jessy 15’ build log - Philadelphia, PA

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Drilling the holes for the bow-eye got me thinking about putting in a drain plug at the transom. Any advice of tips?  I'm thinking an inch off the aft sole on centerline in the transom. I'm thinking about installing it towards the end of the build, after the hull is glassed. I'll reference the link Alan posted above.  

 

Also, talk to me about flotation for the port and starboard compartments.  I know I don't want pour-in foam and think board foam may be best.  A breather, like this https://www.amazon.com/Benjamin-Obdyke-CBNI-Underlayment-Breather/dp/B007DJ3JQS could surround the compartment. I need advice. 

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In Old Codger, a modified Jessy 15, I filled the aft ends of the side seats with foam cut from two inch insulation board. The "flotation box" has a bulkhead separating it from the rest of the seat. I didn't vent the compartment, but did epoxy coat it thoroughly. Powerboats are required by the USCG to have "upright and level flotation" with motor, gear, and people aboard. I always try to, but don't actually calculate the required flotation or do any tests to be sure it's adequate. I've never heard of anyone being cited for not having it on a home-built boat, but I want it for my own safety. When I used to build fiberglass boats professionally, I had to take one of each model to a testing facility to be float tested.

 

My cockpit is self bailing, so I used regular brass outboard drain tubes in each corner. On boats that are not self bailing, I mount it as low and close to the center-line as I can. I then use a regular boat drain plug. These tubes require a special flanging tool to install. On a thin ply transom, I add a 3/4 inch block where the tube comes through.

 

I have occasionally installed the tube by epoxying it in without flanging it. Let it extend through the transom 1/4 inch or so, and fillet around it. Or if you want it flush, "countersink" the hole a bit so you can fill around the tube with epoxy putty. Be sure the tube is clean and rough-up the surface with some sandpaper so the epoxy will get a good grip.

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Chick, thanks for the advice.  For the boat to be self-bailing, the sole has to be higher than the water line. So, since I don't know the waterline (presumable, it's at or very close to the aft chines), maybe I should wait and install this later on. 

 

Regarding the foam, the Jessy has two large bench seats that run fore and aft.  I'm considering asking Alan if it makes sense to install one of his hatches in each side for additional storage.  I will have to divide each seat in 1/3s and will foam and enclose the outer 1/3s where the inner 1/3 is the hatched compartment.  1332352829_Jessydraw.JPG.345313fe7a9b6a29e370f6b65de64c69.JPG

 

Further, the forward upper compartment can be made watertight by using a properly sealed circular deck hatch.  

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Quick update: the stem inside and out received a layer of glass tape.

8CC8C994-88F8-43CB-A076-470F58D29879.thumb.jpeg.9c1ef642f9a6f276e8ebe0e45ea67563.jpeg

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I cut pieces of glass to fit first then laid them out on a piece of plastic I had on the floor. Un-thickened epoxy was brushed on the inside and outside of the stem. I then wetted our the glass on the floor until it went translucent. 

 

I used double latex gloves so that after handling the glass tape, I peeled them off and had gloves for the brush work, etc. I also slightly cut the ends of the chip brushes to stiffen the bristles. This also allowed me to move the glass tape by gently pressing into it at an angle and forcing it to slide. I had a little trouble with the bow eye stiffener - I probably should have waited and glasses this piece separately or just glasses up the inside of the stem, then adding this stiffener block after. Oh well.

 

33304FAA-1197-4A17-8BE8-E2418E6EE0A5.thumb.jpeg.93c161971597db2107c14f98c60b78bf.jpeg

I removed the centerboard and wire ties along the bottom, finished the gaps with thickened epoxy, then sanded smooth in preparation for the two layers of 3” glass tape along the keel. I drew two parallel lines 2” off the center line. This will allow each piece of tape to overlay by an inch and thought this would make the tape job neat in places that will be seen.

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Keel with two layers of overlapping glass.

I started with a brush, then moved to a bondo spreader to wet the glass in place. 8DAE14FC-A2C3-45DC-BCBC-A9863AF06A98.thumb.jpeg.995b428bc4ab17f23fe9c91dbf737a62.jpegB38E27C9-7F83-4AF4-A848-6946F9AAA9C8.thumb.jpeg.2cec8c4346cbc3e3a79ee057c7648ba3.jpegF240744F-697C-4BD6-BAA8-05EACBEF097F.thumb.jpeg.081b2475744b369a654dfd34be807fac.jpeg

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Hey Justin, 
Long reply to follow...

With regards to modifying the seating compartment... 

At issue is one of flotation. The uscg does not recognize air chambers as flotation and when tested, holes are specified to be drilled into any air compartments such that they completely flood for the flotation and level-flotation tests. In the eyes of the CG,  B&B is the "builder" of your boat because we manufactured the kit (i know it's weird) and so we are required to issue an HIN number as well as a capacity plaque based on the design. If you were building from plans, we don't have to issue these. In the US, the CG does not certify boats instead there is a system of "self certification".

 

This article is helpful. https://uscgboating.org/library/boating-safety-circulars/Boating-Safety-Circular-Spring-2016.pdf

Excerpt from above article on boat safety certification....

Quote

Numerous questions come up during the process of issuing Manufacturer Identification Codes (MIC). However, one question seems to resonate over and over again; “how do I get my boat certified by the Coast Guard”? Well, the simple answer is that the Coast Guard does not certify boats intended for the recreational market. So what does it mean on the capacity plate when it says, “This boat complies with U.S. Coast Guard Safety standards in effect on the date of certification”? If the Coast Guard doesn’t certify boats, then why is there a “date of certification”? The recreational boat building industry operates on a self-certification system. The government places the burden on the builder of ensuring that all the Federal regulations are met. This certification language simply means that the builder is aware of the Federal regulations that are published in our Boatbuilder’s Handbook, available on our website at http://www.uscgboating.org/regulations/ boatbuilders-handbook-p1-table-ofcontents.php, that the builder understands how to comply with those regulations, and that the builder certifies that the boat was built in compliance with those regulations. There are instances whereby a builder may not do calculations correctly or may misinterpret the way a regulation is written. To lessen the problems the builder may have in complying with the regulations, the Boat Builder’s Handbook contains compliance guidelines that provide plain language interpretations of the regulations to assist the builder in understanding the regulations so he can comply with them. Additionally, the Coast Guard has contracted factory inspectors who visit boatbuilding factories, acting on behalf of the Coast Guard, whose purpose it is to communicate to the builder why it is important to comply with the regulations, educate the builder on how to comply with the regulations, and perform inspections of the builder’s boats to ensure compliance with the regulations.

 

This document also applies. It was designed by the USCG to be used by those building boat "in their backyard" who wouldn't call themselves boat "manufacturers" but nonetheless were building boats at a regular rate and selling them. http://newboatbuilders.com/docs/backyardboatbuilders.pdf. This is a boiled down version of the CGs boat building handbook. https://www.uscgboating.org/regulations/builders-handbook-downloads.php

 

B&B uses the USCGs "Boat building handbook" when designing to establish capacity, safe loading, power and flotation. The point of all this is to reduce boating accidents which are mainly seen in powerboats under 20 feet since they are the most common vessel and where the most safety gains can be made in the eyes of the CG. I think the name of the game is "liability".  If there is not enough foam flotation in place based on the requirements for recreational boats and then the boat is sold to someone who cannot swim and they run over something causing the boat to flood and sink or capsize due to insufficient flotation installed by the builder then it's theoretically possible that the builder could be held responsible. This is not going to be something most backyard builders will ever deal with but something that larger production boat manufacturers certainly would and why they would need to certify their boats with tank testing etc and have all the documentation of flotation design. Kit boat builders are technically held to the same standard but if you never sold the boat to anyone then you can do whatever you want. 

 

So, finally the question. Can you do it? I am not sure. haha. But we can certainly figure out how much extra foam flotation we gave in the design and then recalculate. It could be that no change is needed or that the only change in order to remain in compliance with the guidelines above for flotation is that a smaller maximum Horsepower be specified or fewer passengers/smaller maximum capacity be specified on the capacity plate. You or us (or anyone) can go through the numbers and calculate it. It's a bit easier for us because we have the exact volumes available on the 3-d computer model of the boat.  

 

The first question would be what motor are you planning to use? 

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The plans say 25hp max, so I think I'll go that route.  Probably Yamaha, however, I have not spent any time looking into it. I assume you need an engine choice to figure out weight?

32552267_Yamaha25hpoutboard.JPG.d8fff00b4307723a3ad7446292367e45.JPG

 

126lbs for the 15" shaft and 143lbs for the 23" shaft.

 

About the rest of the above, thanks, this was very helpful to read. I would still fill the side compartments with foam as I was just thinking the center portion of the seating area could be used as storage or a cooler.  I know you design plans that way you do for a reason. However, this is a custom boat, so I am trying to reconcile those two facts.  1. Safety 2. Function.

 

I figured I would attach this file as it may be useful to someone reading this some day. 

Backyard built boats - things you may not know.pdf

Edited by Justin C
Edited to include engine spec info

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Thanks for the info Alan. i think it's important to be prepared for the possibility of an accident by trying to have proper flotation.

Justin, here's a great source for a motor. Good prices, service, and free shipping. I've bought two motors from them and was very satisfied! https://onlineoutboards.com/

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47 minutes ago, Chick Ludwig said:

Thanks for the info Alan. i think it's important to be prepared for the possibility of an accident by trying to have proper flotation.

Justin, here's a great source for a motor. Good prices, service, and free shipping. I've bought two motors from them and was very satisfied! https://onlineoutboards.com/

Chick, thanks for that link - I'll check it out. 

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Despite saying earlier that I may stay away from pour in foam, I am considering using this 2lb urethane foam http://www.uscomposites.com/foam.html. I can't seem to find marine grade board flotation at a reasonable price and googling marine flotation yields mostly pour in foam.  Once I have the side compartments built out (with or without modifying them for storage/cooler - see above), I'm going to create cardboard forms and pour the foam outside of the boat and then install the custom molded pieces into their respective spaces.  Can I completely encapsulate the foam blocks with epoxy? I would never have to worry about the foam breaking down due to condensate. 

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Don't worry about "marine" foam.I use blue insulation foam sheets from a big box store. It's enclosed in the flotation box, so you don't need to be concerned with it breaking down from gas and oil. Cut pieces to fit. I never poxy coat them.

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53 minutes ago, Chick Ludwig said:

Don't worry about "marine" foam.I use blue insulation foam sheets from a big box store. It's enclosed in the flotation box, so you don't need to be concerned with it breaking down from gas and oil. Cut pieces to fit. I never poxy coat them.

Great to hear - I have to head to one tonight for some other items and will pick up some sheets. 

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On 8/20/2019 at 8:06 AM, Chick Ludwig said:

"My cockpit is self bailing, so I used regular brass outboard drain tubes in each corner. On boats that are not self bailing, I mount it as low and close to the center-line as I can. I then use a regular boat drain plug. These tubes require a special flanging tool to install. On a thin ply transom, I add a 3/4 inch block where the tube comes through."

Chick, do you have/can you take pictures to show the plug inside and out? If you mounted it as low and close to the center-line, didn't you go through the transom stiffeners which are much thicker than the ply transom?  Not sure why a 3/4" block would be used in this area if it's already thick. Did you wait until the end of the build to install the plug?

707C572E-F584-448C-9631-3E060BE94E52.thumb.jpeg.1e3784721f748c8305216a80b1bd6061.jpeg

 

On a side note, I added two staggered layers of glass tape along the bottom to transom seam.  I marked lines two inches off center to keep the tape straight.  I also glassed 1/2 way to the bow along the inside chine. I like having the room to work and decided to glass as much as I can before I compartment off the boat with longitudinals and bulkheads. 

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My Jessy has been modified with a self bailing cockpit so there is not a drain at the lowest point in the center. I was referring to center plug in past boats that I've built. The 3/4" block was to give a thick enough area to install the brass drain plug. These were either plywood boats with only the 1/4" transom ply, or fiberglass boats that didn't have wood laminated in at the bottom. The flanging tool requires about 1" thickness to work. I don't have any boats anymore with that arrangement. My Jessy transom is thick enough that I didn't need the little block.

 

The picture of your boat shows a thick center of the transom. As long as there is not an inside keelson in the way, just install the drain right in the center. Either buy, beg, borrow,or steal a flanging tool, or install the brass tube as I mentioned back in that comment. If you don't get a flanging tool, be sure the tube comes through the transom high enough that the plug will clear the bottom. I install it from the outside so the un-flanged end is inside.

 

By-the-way, be sure that any external keel or skeg has a LONG taper in the aft end so it doesn't cause the prop to cavitate in the turns. (Don't ask me why I know that....)

Here is the flanging tool. (They call it a flaring tool.) https://www.amazon.com/520290-1-Drain-Tube-Flaring-Tool/dp/B0082ANA0C/ref=sr_1_1?crid=2V5SK33ALUQ1K&keywords=drain+tube+flanging+tool&qid=1567627324&s=gateway&sprefix=sdrai+tube+flanging+tool%2Caps%2C143&sr=8-1

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I've never come across a flanging (flaring) tool. I certainly didn't know how to use one, but a quick google has me thinking it's not difficult.  I came across this crude video on how to install a tube.  I'l going to read up on the Gougeon Brothers book, chapter 14., on hardware bonding. 

 

 

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It's EASY! Hardest part is cutting the tube to length. I clamp it in my vice. Ya gotta have a dowel to insert in the tube to keep from crushing it in the vice while you cut with a hack saw. I actually used a die grinder with a cutoff blade. I could hold the tube with my channel lock pliers with one hand and the tool with the other.

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1 hour ago, Chick Ludwig said:

It's EASY! Hardest part is cutting the tube to length. I clamp it in my vice. Ya gotta have a dowel to insert in the tube to keep from crushing it in the vice while you cut with a hack saw. I actually used a die grinder with a cutoff blade. I could hold the tube with my channel lock pliers with one hand and the tool with the other.

+1. Holding the tube with channel locks and using a cutoff wheel was exactly what I was thinking.  I am also going to coat the inside of the cutout with un-thickened and maybe a little thickened epoxy.  No water will be getting in there. 

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I am close to being done as much as I can do in the interior of the boat before I start the installation of the bulkheads and compartments, etc.  I have all these pieces laying around and to me, it makes complete sense to set up a large plastic sheet and coat all the pieces with a layer or two of epoxy now before they are installed and or/taped in.  The centerboard in particular needed quite a bit of flexing to get it into position and the fully cured epoxy may crack. Thoughts? Any potential problems with doing this?

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On 9/6/2019 at 9:55 AM, Justin C said:

Thoughts? Any potential problems with doing this?

Yep, I quoted myself.  I threw caution to the wind and rolled a coat of epoxy onto one side of the seat tops, forward casting platform, longitudinal bulkheads and forward lower bulkhead.  It went on easy. I came back 6hrs later and the smooth surface turned into a bumpy surface which will need to be sanded down.  I used the Wooster 1/8" foam roller. I guess I should have tipped the epoxy coat with a brush after to knock the air bubbles down.  I'll try to do that on the non-coated side of the above named pieces and see how that works.  I think I may also be able to coat the center bulkhead and flex it without the epoxy breaking.  I'll use the longitudinals with 2 coats of epoxy as a test and if it works, I'll coat the center frame before installing it.  

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