Building a KARA Hummer Layout Duck Boat

DustyMark said:

Building the Lower Frame

The Requirement

I moved back to MN in June 2014, after nearly 30 years away, and my brother quickly introduced me to duck hunting. We're not on any of the major flyways here, so we need to put everything in our favor possible. We read about the advantages of layout boats in providing maximum concealment from wary ducks and talked about it in the duck blind all last season. Our hunting party consists of my brother, my nephew, and me and we decided to build three one-man layout boats.

The Boat

We chose the KARA Hummer, a very popular and reasonably simple boat to build. Follow this link to, Rob Leonard's, web site. The boat is 14' long, has a beam of 45 1/2", is 11 1/14" deep not counting the skegs, and often weighs in at about 120 pounds. It is supposedly very stable as a shooting platform. I plan to propel it in open water with oars that I will make from Chesapeake Light Craft plans . Once we get into the wild rice, I will propel it with a Superstick fiberglass push pole .

The Materials

Each builder will chose materials based on availability and budget. I bought premium white pine from Menards, when it was on sale a few months ago, for the framework. It is free of knots and quite light, but it is pretty soft. I chose 1/4" Marine Douglas fir plywood for the skin that I special ordered from Menards at $35 per sheet delivered. I'm trying Raka epoxy for the first time and will glass the inside surfaces of the boat with 2.3 oz. cloth, while the outer surfaces will receive 6 oz. cloth.

The Builder

I'm a fairly experienced boat builder. I've built two kayaks from plans, one kayak from a kit, and a small ski boat from a plan. I'll depart from the plan occasionally to incorporate techniques from past builds.

Frame

The plan calls for 3/4" by 13' 11" boards for the gunnels. Other blogs speak of these breaking while torturing them into shape. I decided to laminate my gunnels from two layers of 3/8" wood to make the bend easier and eliminate drama during assembly. I also chose to scarf 8' boards together to meet the length requirement. These choices added extra steps, but were worth it.

The ribs and end pieces are dry fit with screws to the gunnels.

I paused the build to construct a pair of simple, sturdy saw horses.

The lower frame is assembled with screws and epoxy. All the clamps were needed to laminate the two layers of the gunnels.

Next

In the next installment, I'll assemble the upper frame.

Click to expand...

DustyMark said:

Building the Lower Frame

The Requirement

I moved back to MN in June 2014, after nearly 30 years away, and my brother quickly introduced me to duck hunting. We're not on any of the major flyways here, so we need to put everything in our favor possible. We read about the advantages of layout boats in providing maximum concealment from wary ducks and talked about it in the duck blind all last season. Our hunting party consists of my brother, my nephew, and me and we decided to build three one-man layout boats.

The Boat

We chose the KARA Hummer, a very popular and reasonably simple boat to build. Follow this link to, Rob Leonard's, web site. The boat is 14' long, has a beam of 45 1/2", is 11 1/14" deep not counting the skegs, and often weighs in at about 120 pounds. It is supposedly very stable as a shooting platform. I plan to propel it in open water with oars that I will make from Chesapeake Light Craft plans . Once we get into the wild rice, I will propel it with a Superstick fiberglass push pole .

The Materials

Each builder will chose materials based on availability and budget. I bought premium white pine from Menards, when it was on sale a few months ago, for the framework. It is free of knots and quite light, but it is pretty soft. I chose 1/4" Marine Douglas fir plywood for the skin that I special ordered from Menards at $35 per sheet delivered. I'm trying Raka epoxy for the first time and will glass the inside surfaces of the boat with 2.3 oz. cloth, while the outer surfaces will receive 6 oz. cloth.

The Builder

I'm a fairly experienced boat builder. I've built two kayaks from plans, one kayak from a kit, and a small ski boat from a plan. I'll depart from the plan occasionally to incorporate techniques from past builds.

Frame

The plan calls for 3/4" by 13' 11" boards for the gunnels. Other blogs speak of these breaking while torturing them into shape. I decided to laminate my gunnels from two layers of 3/8" wood to make the bend easier and eliminate drama during assembly. I also chose to scarf 8' boards together to meet the length requirement. These choices added extra steps, but were worth it.

The ribs and end pieces are dry fit with screws to the gunnels.

I paused the build to construct a pair of simple, sturdy saw horses.

The lower frame is assembled with screws and epoxy. All the clamps were needed to laminate the two layers of the gunnels.

Next

In the next installment, I'll assemble the upper frame.

Click to expand...

DustyMark said:

Building the Lower Frame

The Requirement

I moved back to MN in June 2014, after nearly 30 years away, and my brother quickly introduced me to duck hunting. We're not on any of the major flyways here, so we need to put everything in our favor possible. We read about the advantages of layout boats in providing maximum concealment from wary ducks and talked about it in the duck blind all last season. Our hunting party consists of my brother, my nephew, and me and we decided to build three one-man layout boats.

The Boat

We chose the KARA Hummer, a very popular and reasonably simple boat to build. Follow this link to, Rob Leonard's, web site. The boat is 14' long, has a beam of 45 1/2", is 11 1/14" deep not counting the skegs, and often weighs in at about 120 pounds. It is supposedly very stable as a shooting platform. I plan to propel it in open water with oars that I will make from Chesapeake Light Craft plans . Once we get into the wild rice, I will propel it with a Superstick fiberglass push pole .

The Materials

Each builder will chose materials based on availability and budget. I bought premium white pine from Menards, when it was on sale a few months ago, for the framework. It is free of knots and quite light, but it is pretty soft. I chose 1/4" Marine Douglas fir plywood for the skin that I special ordered from Menards at $35 per sheet delivered. I'm trying Raka epoxy for the first time and will glass the inside surfaces of the boat with 2.3 oz. cloth, while the outer surfaces will receive 6 oz. cloth.

The Builder

I'm a fairly experienced boat builder. I've built two kayaks from plans, one kayak from a kit, and a small ski boat from a plan. I'll depart from the plan occasionally to incorporate techniques from past builds.

Frame

The plan calls for 3/4" by 13' 11" boards for the gunnels. Other blogs speak of these breaking while torturing them into shape. I decided to laminate my gunnels from two layers of 3/8" wood to make the bend easier and eliminate drama during assembly. I also chose to scarf 8' boards together to meet the length requirement. These choices added extra steps, but were worth it.

The ribs and end pieces are dry fit with screws to the gunnels.

I paused the build to construct a pair of simple, sturdy saw horses.

The lower frame is assembled with screws and epoxy. All the clamps were needed to laminate the two layers of the gunnels.

Next

In the next installment, I'll assemble the upper frame.

Click to expand...

DustyMark said:

Building the Lower Frame

The Requirement

I moved back to MN in June 2014, after nearly 30 years away, and my brother quickly introduced me to duck hunting. We're not on any of the major flyways here, so we need to put everything in our favor possible. We read about the advantages of layout boats in providing maximum concealment from wary ducks and talked about it in the duck blind all last season. Our hunting party consists of my brother, my nephew, and me and we decided to build three one-man layout boats.

The Boat

We chose the KARA Hummer, a very popular and reasonably simple boat to build. Follow this link to, Rob Leonard's, web site. The boat is 14' long, has a beam of 45 1/2", is 11 1/14" deep not counting the skegs, and often weighs in at about 120 pounds. It is supposedly very stable as a shooting platform. I plan to propel it in open water with oars that I will make from Chesapeake Light Craft plans . Once we get into the wild rice, I will propel it with a Superstick fiberglass push pole .

The Materials

Each builder will chose materials based on availability and budget. I bought premium white pine from Menards, when it was on sale a few months ago, for the framework. It is free of knots and quite light, but it is pretty soft. I chose 1/4" Marine Douglas fir plywood for the skin that I special ordered from Menards at $35 per sheet delivered. I'm trying Raka epoxy for the first time and will glass the inside surfaces of the boat with 2.3 oz. cloth, while the outer surfaces will receive 6 oz. cloth.

The Builder

I'm a fairly experienced boat builder. I've built two kayaks from plans, one kayak from a kit, and a small ski boat from a plan. I'll depart from the plan occasionally to incorporate techniques from past builds.

Frame

The plan calls for 3/4" by 13' 11" boards for the gunnels. Other blogs speak of these breaking while torturing them into shape. I decided to laminate my gunnels from two layers of 3/8" wood to make the bend easier and eliminate drama during assembly. I also chose to scarf 8' boards together to meet the length requirement. These choices added extra steps, but were worth it.

The ribs and end pieces are dry fit with screws to the gunnels.

I paused the build to construct a pair of simple, sturdy saw horses.

The lower frame is assembled with screws and epoxy. All the clamps were needed to laminate the two layers of the gunnels.

Next

In the next installment, I'll assemble the upper frame.

Click to expand...

DustyMark said:

Building the Lower Frame

The Requirement

I moved back to MN in June 2014, after nearly 30 years away, and my brother quickly introduced me to duck hunting. We're not on any of the major flyways here, so we need to put everything in our favor possible. We read about the advantages of layout boats in providing maximum concealment from wary ducks and talked about it in the duck blind all last season. Our hunting party consists of my brother, my nephew, and me and we decided to build three one-man layout boats.

The Boat

We chose the KARA Hummer, a very popular and reasonably simple boat to build. Follow this link to, Rob Leonard's, web site. The boat is 14' long, has a beam of 45 1/2", is 11 1/14" deep not counting the skegs, and often weighs in at about 120 pounds. It is supposedly very stable as a shooting platform. I plan to propel it in open water with oars that I will make from Chesapeake Light Craft plans . Once we get into the wild rice, I will propel it with a Superstick fiberglass push pole .

The Materials

Each builder will chose materials based on availability and budget. I bought premium white pine from Menards, when it was on sale a few months ago, for the framework. It is free of knots and quite light, but it is pretty soft. I chose 1/4" Marine Douglas fir plywood for the skin that I special ordered from Menards at $35 per sheet delivered. I'm trying Raka epoxy for the first time and will glass the inside surfaces of the boat with 2.3 oz. cloth, while the outer surfaces will receive 6 oz. cloth.

The Builder

I'm a fairly experienced boat builder. I've built two kayaks from plans, one kayak from a kit, and a small ski boat from a plan. I'll depart from the plan occasionally to incorporate techniques from past builds.

Frame

The plan calls for 3/4" by 13' 11" boards for the gunnels. Other blogs speak of these breaking while torturing them into shape. I decided to laminate my gunnels from two layers of 3/8" wood to make the bend easier and eliminate drama during assembly. I also chose to scarf 8' boards together to meet the length requirement. These choices added extra steps, but were worth it.

The ribs and end pieces are dry fit with screws to the gunnels.

I paused the build to construct a pair of simple, sturdy saw horses.

The lower frame is assembled with screws and epoxy. All the clamps were needed to laminate the two layers of the gunnels.

Next

In the next installment, I'll assemble the upper frame.

Click to expand...

DustyMark said:

Building the Lower Frame

The Requirement

I moved back to MN in June 2014, after nearly 30 years away, and my brother quickly introduced me to duck hunting. We're not on any of the major flyways here, so we need to put everything in our favor possible. We read about the advantages of layout boats in providing maximum concealment from wary ducks and talked about it in the duck blind all last season. Our hunting party consists of my brother, my nephew, and me and we decided to build three one-man layout boats.

The Boat

We chose the KARA Hummer, a very popular and reasonably simple boat to build. Follow this link to, Rob Leonard's, web site. The boat is 14' long, has a beam of 45 1/2", is 11 1/14" deep not counting the skegs, and often weighs in at about 120 pounds. It is supposedly very stable as a shooting platform. I plan to propel it in open water with oars that I will make from Chesapeake Light Craft plans . Once we get into the wild rice, I will propel it with a Superstick fiberglass push pole .

The Materials

Each builder will chose materials based on availability and budget. I bought premium white pine from Menards, when it was on sale a few months ago, for the framework. It is free of knots and quite light, but it is pretty soft. I chose 1/4" Marine Douglas fir plywood for the skin that I special ordered from Menards at $35 per sheet delivered. I'm trying Raka epoxy for the first time and will glass the inside surfaces of the boat with 2.3 oz. cloth, while the outer surfaces will receive 6 oz. cloth.

The Builder

I'm a fairly experienced boat builder. I've built two kayaks from plans, one kayak from a kit, and a small ski boat from a plan. I'll depart from the plan occasionally to incorporate techniques from past builds.

Frame

The plan calls for 3/4" by 13' 11" boards for the gunnels. Other blogs speak of these breaking while torturing them into shape. I decided to laminate my gunnels from two layers of 3/8" wood to make the bend easier and eliminate drama during assembly. I also chose to scarf 8' boards together to meet the length requirement. These choices added extra steps, but were worth it.

The ribs and end pieces are dry fit with screws to the gunnels.

I paused the build to construct a pair of simple, sturdy saw horses.

The lower frame is assembled with screws and epoxy. All the clamps were needed to laminate the two layers of the gunnels.

Next

In the next installment, I'll assemble the upper frame.

Click to expand...

DustyMark said:

Planing the Gunnels

Tools for the Job

Planing the gunnels requires a sharp hand plane, a straight edge and a flexible stick. I use a 10" smoothing plane for this task since it is easier to handle than a longer plane and much of the work is on a curve. On larger boats, I've used a hand-held power planer to good effect. I started with that and it seemed like overkill for 3/4" gunnels.

Rib Transitions

The angle that the plywood skin will land on the gunnel changes throughout the length of the gunnel. My youngest son's approach to cooking is that you don't need to slavishly measure as much as "you've just gotta love it." That's not a bad approach for planing the gunnels. I use a straight edge from the side deck support cleat to check my progress in the straight areas. When I hit the curves near the bow and stern, I switch to bending a flexible piece of hardwood strip about 1/4" thick over the ribs to predict how the skin of the boat will lay.

This is the deck side of the gunnel looking toward the cockpit before planing. Notice that the cockpit deck support is also a little bit high in this photo. I may have to redesign that support prior to building boats two and three…

After planing, the ribs flow nicely into the gunnel.

The transitions from the ribs to the gunnels on the hull side are more severe. This requires a steeper angle and more planing to achieve a nice transition.

After planing, the hull side of the rib flows into the gunnel. Notice there is much more surface area for the plywood hull to bond to the gunnel when it's nailed and glued. It will be easy for a nail head to encroach into the cargo compartment if I start it too close to the center of the gunnel during plywood installation.

Here's my 10" smoothing plane laying in a pile of shavings from one gunnel.

Even though I spaced the screws through the gunnel pretty close, I still hit screw heads when I planed the hull side of the gunnel. However, my Tormek sharpening system made short work of grinding a clean edge on the battered blade.

Results

My planing job isn't perfect, but it is likely good enough. I'll dry fit the plywood and plane any problem spots that become apparent with the actual skin applied.

Next

In the next installment, I'll discuss bracket installation for stabilizer holes that will hold my anchor pole.

Click to expand...

DustyMark said:

Planing the Gunnels

Tools for the Job

Planing the gunnels requires a sharp hand plane, a straight edge and a flexible stick. I use a 10" smoothing plane for this task since it is easier to handle than a longer plane and much of the work is on a curve. On larger boats, I've used a hand-held power planer to good effect. I started with that and it seemed like overkill for 3/4" gunnels.

Rib Transitions

The angle that the plywood skin will land on the gunnel changes throughout the length of the gunnel. My youngest son's approach to cooking is that you don't need to slavishly measure as much as "you've just gotta love it." That's not a bad approach for planing the gunnels. I use a straight edge from the side deck support cleat to check my progress in the straight areas. When I hit the curves near the bow and stern, I switch to bending a flexible piece of hardwood strip about 1/4" thick over the ribs to predict how the skin of the boat will lay.

This is the deck side of the gunnel looking toward the cockpit before planing. Notice that the cockpit deck support is also a little bit high in this photo. I may have to redesign that support prior to building boats two and three…

After planing, the ribs flow nicely into the gunnel.

The transitions from the ribs to the gunnels on the hull side are more severe. This requires a steeper angle and more planing to achieve a nice transition.

After planing, the hull side of the rib flows into the gunnel. Notice there is much more surface area for the plywood hull to bond to the gunnel when it's nailed and glued. It will be easy for a nail head to encroach into the cargo compartment if I start it too close to the center of the gunnel during plywood installation.

Here's my 10" smoothing plane laying in a pile of shavings from one gunnel.

Even though I spaced the screws through the gunnel pretty close, I still hit screw heads when I planed the hull side of the gunnel. However, my Tormek sharpening system made short work of grinding a clean edge on the battered blade.

Results

My planing job isn't perfect, but it is likely good enough. I'll dry fit the plywood and plane any problem spots that become apparent with the actual skin applied.

Next

In the next installment, I'll discuss bracket installation for stabilizer holes that will hold my anchor pole.

Click to expand...

DustyMark said:

Applying the Plywood Hull Panels

Fiberglass Experiment

I applied a layer of fiberglass cloth to the plywood hull panels before work, betting they would be "green" cured in the afternoon upon my return. Using Raka 127 Resin and Raka 350 hardener at 72 degrees and 48% humidity the fiberglass was set perfectly in about 8 hours. It was bonded, yet flexible enough to not restrict the plywood from curving around the hull ribs.

The epoxy is wet into the fiberglass cloth with a foam roller.

I never pay extra to ship the fiberglass on a roll, so there are wrinkles that need to be worked out with a spreader.

It doesn't take much effort to work out the wrinkles.

Immediately before applying the plywood panels, I applied a second layer of epoxy to fill the weave on the fiberglass cloth.

Hull Plywood Application

I mixed up a 6 ounce batch of thickened epoxy and my wife and I each took half the batch and spread it on the ribs and gunnels. We then screwed the middle hull panel, we had fit earlier, into position. We followed the plan instructions and worked our way from the middle, down the ribs, and onto the gunnels to affix the panels with silicon bronze ring shank nails. It took more force than I anticipated to bend the plywood to the outer ribs, but we succeeded. We then applied each end panel in a similar manner.

Setting some nails with a punch.

The hull took a nice shape.

It's definitely starting to look like a boat!

Upright view.

Carnage

I forgot to make my alignment tool that helps mark the nail holes to assure they landed in the center of the 3/4" gunnel. I realized this after we had already spread the thickened epoxy on the ribs and gunnels. The epoxy would have set up if I had taken the extra time to make the tool, so we rolled with it.

Unfortunately, I missed the mark on six nails and busted through the gunnel on either the inside or outside edge.

I split the wood the rest of the way and used the chip to make the repair. Thickened epoxy is both gap filling and structural and makes these repairs easy. Here I am applying the chip to the bed of epoxy.

The chip fit well in the repair. I placed tape over it and then clamped it lightly in position. I did this for all six damaged areas.

Alignment Tool

This simple little tool would have saved me 6 small repair jobs and also prevented me from filing most of the heads off of quite a few nails when I rounded over the hull edge in preparation for fiberglassing.

This fits over the plywood that is extending from the edge of the gunnel and finds the center of the gunnel. I trim my plywood edges ahead of time, so the slot on the alignment tool doesn't need to be crazy deep. I cut the edges of the jig to 15 degrees since the entire hull and deck meet the gunnels at about that angle.

Flushing the Edges

The hull panels needed to made flush with the gunnels.

A router with a flush trimming bit removed much of the excess wood, but since the hull is at an angle, there was at least 1/4' of wood remaining to remove all the way around. NOTE: Later in the project, I decided to not chicken out when flush trimming the deck panels. I kept the router level to the ground for a finishing cut to allow the bearing to rub flat on the gunnel and it removed all the plywood flush to the gunnel. The reason I didn't try that on the hull plywood was fear of going beyond level and removing some of the gunnel. However, removing the remaining 1/4" of hull plywood around the perimeter of the boat with hand tools was way too much work…that's what drove me to take the chance on the deck plywood. It worked fine.

I settled on my aggressive cross-cut saw and an old file that has what looks like rows of hacksaw blades for teeth. Both of these worked well for the task.

Rounding the Edges

The hull and the deck receive fiberglass. The fiberglass needs to bend around the gunnel to provide a double layer of protection to the gunnel. However fiberglass can't be applied around a sharp angle. That's why the edges of the hull and the deck must be rounded where they meet the gunnel. The previously mentioned file was perfect for this since many of the nail heads were too close to the edge. Thankfully, I used silicon bronze nails to apply the hull and they were easy to file off when needed.

Rounded edge.

Another view.

Conclusion

Even with the challenges, I'm happy with the way the hull turned out. This is a duck boat that gets painted and nobody will see the mistakes! Fiberglassing the inside of the hull panels with 2.3 ounce cloth worked well and I will do it to the deck panels also. It's an effective means of applying a light layer of waterproofing.

Next

In the next installment, I'll discuss sealing the hull interior for water protection.

Click to expand...

DustyMark said:

Applying the Plywood Hull Panels

Fiberglass Experiment

I applied a layer of fiberglass cloth to the plywood hull panels before work, betting they would be "green" cured in the afternoon upon my return. Using Raka 127 Resin and Raka 350 hardener at 72 degrees and 48% humidity the fiberglass was set perfectly in about 8 hours. It was bonded, yet flexible enough to not restrict the plywood from curving around the hull ribs.

The epoxy is wet into the fiberglass cloth with a foam roller.

I never pay extra to ship the fiberglass on a roll, so there are wrinkles that need to be worked out with a spreader.

It doesn't take much effort to work out the wrinkles.

Immediately before applying the plywood panels, I applied a second layer of epoxy to fill the weave on the fiberglass cloth.

Hull Plywood Application

I mixed up a 6 ounce batch of thickened epoxy and my wife and I each took half the batch and spread it on the ribs and gunnels. We then screwed the middle hull panel, we had fit earlier, into position. We followed the plan instructions and worked our way from the middle, down the ribs, and onto the gunnels to affix the panels with silicon bronze ring shank nails. It took more force than I anticipated to bend the plywood to the outer ribs, but we succeeded. We then applied each end panel in a similar manner.

Setting some nails with a punch.

The hull took a nice shape.

It's definitely starting to look like a boat!

Upright view.

Carnage

I forgot to make my alignment tool that helps mark the nail holes to assure they landed in the center of the 3/4" gunnel. I realized this after we had already spread the thickened epoxy on the ribs and gunnels. The epoxy would have set up if I had taken the extra time to make the tool, so we rolled with it.

Unfortunately, I missed the mark on six nails and busted through the gunnel on either the inside or outside edge.

I split the wood the rest of the way and used the chip to make the repair. Thickened epoxy is both gap filling and structural and makes these repairs easy. Here I am applying the chip to the bed of epoxy.

The chip fit well in the repair. I placed tape over it and then clamped it lightly in position. I did this for all six damaged areas.

Alignment Tool

This simple little tool would have saved me 6 small repair jobs and also prevented me from filing most of the heads off of quite a few nails when I rounded over the hull edge in preparation for fiberglassing.

This fits over the plywood that is extending from the edge of the gunnel and finds the center of the gunnel. I trim my plywood edges ahead of time, so the slot on the alignment tool doesn't need to be crazy deep. I cut the edges of the jig to 15 degrees since the entire hull and deck meet the gunnels at about that angle.

Flushing the Edges

The hull panels needed to made flush with the gunnels.

A router with a flush trimming bit removed much of the excess wood, but since the hull is at an angle, there was at least 1/4' of wood remaining to remove all the way around. NOTE: Later in the project, I decided to not chicken out when flush trimming the deck panels. I kept the router level to the ground for a finishing cut to allow the bearing to rub flat on the gunnel and it removed all the plywood flush to the gunnel. The reason I didn't try that on the hull plywood was fear of going beyond level and removing some of the gunnel. However, removing the remaining 1/4" of hull plywood around the perimeter of the boat with hand tools was way too much work…that's what drove me to take the chance on the deck plywood. It worked fine.

I settled on my aggressive cross-cut saw and an old file that has what looks like rows of hacksaw blades for teeth. Both of these worked well for the task.

Rounding the Edges

The hull and the deck receive fiberglass. The fiberglass needs to bend around the gunnel to provide a double layer of protection to the gunnel. However fiberglass can't be applied around a sharp angle. That's why the edges of the hull and the deck must be rounded where they meet the gunnel. The previously mentioned file was perfect for this since many of the nail heads were too close to the edge. Thankfully, I used silicon bronze nails to apply the hull and they were easy to file off when needed.

Rounded edge.

Another view.

Conclusion

Even with the challenges, I'm happy with the way the hull turned out. This is a duck boat that gets painted and nobody will see the mistakes! Fiberglassing the inside of the hull panels with 2.3 ounce cloth worked well and I will do it to the deck panels also. It's an effective means of applying a light layer of waterproofing.

Next

In the next installment, I'll discuss sealing the hull interior for water protection.

Click to expand...

DustyMark said:

Applying the Plywood Hull Panels

Fiberglass Experiment

I applied a layer of fiberglass cloth to the plywood hull panels before work, betting they would be "green" cured in the afternoon upon my return. Using Raka 127 Resin and Raka 350 hardener at 72 degrees and 48% humidity the fiberglass was set perfectly in about 8 hours. It was bonded, yet flexible enough to not restrict the plywood from curving around the hull ribs.

The epoxy is wet into the fiberglass cloth with a foam roller.

I never pay extra to ship the fiberglass on a roll, so there are wrinkles that need to be worked out with a spreader.

It doesn't take much effort to work out the wrinkles.

Immediately before applying the plywood panels, I applied a second layer of epoxy to fill the weave on the fiberglass cloth.

Hull Plywood Application

I mixed up a 6 ounce batch of thickened epoxy and my wife and I each took half the batch and spread it on the ribs and gunnels. We then screwed the middle hull panel, we had fit earlier, into position. We followed the plan instructions and worked our way from the middle, down the ribs, and onto the gunnels to affix the panels with silicon bronze ring shank nails. It took more force than I anticipated to bend the plywood to the outer ribs, but we succeeded. We then applied each end panel in a similar manner.

Setting some nails with a punch.

The hull took a nice shape.

It's definitely starting to look like a boat!

Upright view.

Carnage

I forgot to make my alignment tool that helps mark the nail holes to assure they landed in the center of the 3/4" gunnel. I realized this after we had already spread the thickened epoxy on the ribs and gunnels. The epoxy would have set up if I had taken the extra time to make the tool, so we rolled with it.

Unfortunately, I missed the mark on six nails and busted through the gunnel on either the inside or outside edge.

I split the wood the rest of the way and used the chip to make the repair. Thickened epoxy is both gap filling and structural and makes these repairs easy. Here I am applying the chip to the bed of epoxy.

The chip fit well in the repair. I placed tape over it and then clamped it lightly in position. I did this for all six damaged areas.

Alignment Tool

This simple little tool would have saved me 6 small repair jobs and also prevented me from filing most of the heads off of quite a few nails when I rounded over the hull edge in preparation for fiberglassing.

This fits over the plywood that is extending from the edge of the gunnel and finds the center of the gunnel. I trim my plywood edges ahead of time, so the slot on the alignment tool doesn't need to be crazy deep. I cut the edges of the jig to 15 degrees since the entire hull and deck meet the gunnels at about that angle.

Flushing the Edges

The hull panels needed to made flush with the gunnels.

A router with a flush trimming bit removed much of the excess wood, but since the hull is at an angle, there was at least 1/4' of wood remaining to remove all the way around. NOTE: Later in the project, I decided to not chicken out when flush trimming the deck panels. I kept the router level to the ground for a finishing cut to allow the bearing to rub flat on the gunnel and it removed all the plywood flush to the gunnel. The reason I didn't try that on the hull plywood was fear of going beyond level and removing some of the gunnel. However, removing the remaining 1/4" of hull plywood around the perimeter of the boat with hand tools was way too much work…that's what drove me to take the chance on the deck plywood. It worked fine.

I settled on my aggressive cross-cut saw and an old file that has what looks like rows of hacksaw blades for teeth. Both of these worked well for the task.

Rounding the Edges

The hull and the deck receive fiberglass. The fiberglass needs to bend around the gunnel to provide a double layer of protection to the gunnel. However fiberglass can't be applied around a sharp angle. That's why the edges of the hull and the deck must be rounded where they meet the gunnel. The previously mentioned file was perfect for this since many of the nail heads were too close to the edge. Thankfully, I used silicon bronze nails to apply the hull and they were easy to file off when needed.

Rounded edge.

Another view.

Conclusion

Even with the challenges, I'm happy with the way the hull turned out. This is a duck boat that gets painted and nobody will see the mistakes! Fiberglassing the inside of the hull panels with 2.3 ounce cloth worked well and I will do it to the deck panels also. It's an effective means of applying a light layer of waterproofing.

Next

In the next installment, I'll discuss sealing the hull interior for water protection.

Click to expand...

DustyMark said:

Applying the Plywood Hull Panels

Fiberglass Experiment

I applied a layer of fiberglass cloth to the plywood hull panels before work, betting they would be "green" cured in the afternoon upon my return. Using Raka 127 Resin and Raka 350 hardener at 72 degrees and 48% humidity the fiberglass was set perfectly in about 8 hours. It was bonded, yet flexible enough to not restrict the plywood from curving around the hull ribs.

The epoxy is wet into the fiberglass cloth with a foam roller.

I never pay extra to ship the fiberglass on a roll, so there are wrinkles that need to be worked out with a spreader.

It doesn't take much effort to work out the wrinkles.

Immediately before applying the plywood panels, I applied a second layer of epoxy to fill the weave on the fiberglass cloth.

Hull Plywood Application

I mixed up a 6 ounce batch of thickened epoxy and my wife and I each took half the batch and spread it on the ribs and gunnels. We then screwed the middle hull panel, we had fit earlier, into position. We followed the plan instructions and worked our way from the middle, down the ribs, and onto the gunnels to affix the panels with silicon bronze ring shank nails. It took more force than I anticipated to bend the plywood to the outer ribs, but we succeeded. We then applied each end panel in a similar manner.

Setting some nails with a punch.

The hull took a nice shape.

It's definitely starting to look like a boat!

Upright view.

Carnage

I forgot to make my alignment tool that helps mark the nail holes to assure they landed in the center of the 3/4" gunnel. I realized this after we had already spread the thickened epoxy on the ribs and gunnels. The epoxy would have set up if I had taken the extra time to make the tool, so we rolled with it.

Unfortunately, I missed the mark on six nails and busted through the gunnel on either the inside or outside edge.

I split the wood the rest of the way and used the chip to make the repair. Thickened epoxy is both gap filling and structural and makes these repairs easy. Here I am applying the chip to the bed of epoxy.

The chip fit well in the repair. I placed tape over it and then clamped it lightly in position. I did this for all six damaged areas.

Alignment Tool

This simple little tool would have saved me 6 small repair jobs and also prevented me from filing most of the heads off of quite a few nails when I rounded over the hull edge in preparation for fiberglassing.

This fits over the plywood that is extending from the edge of the gunnel and finds the center of the gunnel. I trim my plywood edges ahead of time, so the slot on the alignment tool doesn't need to be crazy deep. I cut the edges of the jig to 15 degrees since the entire hull and deck meet the gunnels at about that angle.

Flushing the Edges

The hull panels needed to made flush with the gunnels.

A router with a flush trimming bit removed much of the excess wood, but since the hull is at an angle, there was at least 1/4' of wood remaining to remove all the way around. NOTE: Later in the project, I decided to not chicken out when flush trimming the deck panels. I kept the router level to the ground for a finishing cut to allow the bearing to rub flat on the gunnel and it removed all the plywood flush to the gunnel. The reason I didn't try that on the hull plywood was fear of going beyond level and removing some of the gunnel. However, removing the remaining 1/4" of hull plywood around the perimeter of the boat with hand tools was way too much work…that's what drove me to take the chance on the deck plywood. It worked fine.

I settled on my aggressive cross-cut saw and an old file that has what looks like rows of hacksaw blades for teeth. Both of these worked well for the task.

Rounding the Edges

The hull and the deck receive fiberglass. The fiberglass needs to bend around the gunnel to provide a double layer of protection to the gunnel. However fiberglass can't be applied around a sharp angle. That's why the edges of the hull and the deck must be rounded where they meet the gunnel. The previously mentioned file was perfect for this since many of the nail heads were too close to the edge. Thankfully, I used silicon bronze nails to apply the hull and they were easy to file off when needed.

Rounded edge.

Another view.

Conclusion

Even with the challenges, I'm happy with the way the hull turned out. This is a duck boat that gets painted and nobody will see the mistakes! Fiberglassing the inside of the hull panels with 2.3 ounce cloth worked well and I will do it to the deck panels also. It's an effective means of applying a light layer of waterproofing.

Next

In the next installment, I'll discuss sealing the hull interior for water protection.

Click to expand...

DustyMark said:

Sealing the Hull Interior

Objective

This boat is going to get wet and stay wet for days at a time. I plan to seal the interior with epoxy to give it at least some protection from the elements. My main concern was with the plywood. That is sealed well with the fiberglass cloth. The keel, gunnels, and ribs will be sealed by caulking the seams where they meet the plywood with thickened epoxy and coating the rest with unthickened epoxy.

Caulking

I imagine a builder could use silicone caulk to seal the joints, but I'm using epoxy since it will last just as long as the rest of the boat.

Start with epoxy that is thickened like this.

Plop the epoxy into a 1 quart bag that has the corner nipped off. I use a smooth plastic scraper to move the epoxy into the corner of the bag with the hole.

Squeeze the bag to lay a bead of epoxy on your seams. You need to squirt that epoxy in a timely manner since 3 ounces of epoxy in such a thick blob could cook off pretty quick and it's too expensive to waste.

I cut the edge of a scraper to make a custom scraper of a small radius to spread the epoxy evenly. These beads of epoxy will help prevent water from getting under the keel and the ribs. I applied thickened epoxy to the ribs prior to applying the plywood, so the underside of the ribs are protected.

Painting on the Epoxy

The plywood is already coated with fiberglass and the seams inside are caulked. Next, the rest of the interior is coated with epoxy that is applied with a chip brush. There's nothing special about this and it's pretty much a drudge task. However, timing is something to consider. If you brush epoxy on your caulk seams before they are cured enough, they could run. If you paint the epoxy on at just the right time, it may smooth out any rough areas along the caulk line.

It looks like I'm obtaining satisfactory coverage with two coats of epoxy. Some would advise more, but I own a well-used kayak that I built in 1996 that is doing just fine with two coats. Hopefully I'll be too "smart" to duck hunt 20 years from now!

I'm not neat at this paint work. I got lots of epoxy on my sleeves and some on my pants. Here they are curing before I can bring them upstairs!

Next

In the next installment, I'll show how to keep the anchor pole holes from leaking through the hull.

Click to expand...