This video explains how to mix epoxy with fillers and additives (such as fumed silica or Cabosil) to create thickened epoxy. Thickened epoxy is commonly used to bond wood to itself and other materials in boat building.
You can build your own boat using our plans and instructional videos! The 7th video in the FRS12 how-to build a boat series shows how to fiberglass the boat hull with epoxy resin. This includes laying fiberglass, wetting out the fiberglass, trimming fiberglass and applying fairing filler for easier sanding.
Before You Fiberglass the Boat
We’ve rolled the boat over and the bottom is a little wavy, so we’ve pulled it up and pushed it down where we needed it. Then we pulled thickened epoxy between our zip ties. Once the epoxy cures, we can take all the weight off, cut the zip ties out, and we’ll be ready to prep for glass.
Dry Fit the Fiberglass
We dry fit our fiberglass. Start by sanding the bottom and sides of the boat. We put a 1/4″ radius on the edges so our fiberglass will wrap over easier. To cut the fiberglass, we’re going to cut it six inches longer than the length at the shear, and we’re going to cut it a half inch to an inch longer than our widest dimension. The fiberglass will be longer at the front, so we’ll trim it. We marked ours with a sharpie and cut it with scissors. Just be careful not to nick the fiberglass and pull it apart, because that could show us as an imperfection later in the process you’ll have to work out.
Your edge at the shear bumper can over hang. This is a great way, if you’re unsure of where to cut it. We left it a little long at the shear bumper to make sure we don’t come up short. We can trim it off later when it cures.
The order that we’re applying the fiberglass is the same order we’ll apply it when wet. We’ll start with our sides and then move to the bottom.
So we have the other side on, cut the same way. Two inches of overlap at the front, four inches at the back. The bottom piece is already cut, so we’ll roll it out to show how that is.
The bottom piece of fiberglass will overhang the edges. Once it cures, we’ll trim it off. The reason for the overhang is to reinforce the edge.
We also have a six inch wide strip that goes down the keel and reinforces it, that gives us wear resistance. Both pieces of fiberglass overlap four inches at the rear.
Fill All Holes with Thickened Epoxy Before Applying Fiberglass
We have all the holes from the zip ties, and the seam from our plywood. We’re going to fill all of it in right before we fiberglass. I like to do it right before so that I don’t have to sand it. But, you can do it, let it dry, sand it, and then apply your fiberglass.
What we can do, is take an old shopping card, mix up thickened epoxy, and pull it through, packing it into the holes. Some will go through. We’ll clean that up on the other side when we flip the boat over. Don’t worry about it.
We filled all the holes and cracks in the whole boat with thickened epoxy. Now we’re going to cover the whole boat in epoxy in preparation for glass. We can use a chip brush or a foam roller.
How to Fiberglass the Boat
Now that we’ve covered the whole boat in epoxy, we can apply our fiberglass. We’ll start with the sides.
After it’s laid loosely in position, I’ll come back and work each area to get it to lay down exactly like I want it.
We finished apply the piece of fiberglass, and some of the areas wet through and some haven’t. We’ll take our brush or roller and apply another coat of resin.
The fiberglass is all applied. We have both sides, the bottom and the keel strip on. Let it get tacky. Normally it will take 1-3 hours depending on your temperature. Hotter temperature = quicker cure.
Flood Coat of Fairing Filler
Next we’re going to do a flood coat. We’ve mixed epoxy and added a microlight fairing filler. The purpose of the fairing filler is so you can sand the top of resin without sanding away the fiberglass. Using a chip brush, I’ll brush on a light coat to the entire hull.
The fiberglass is cured. We trimmed off the edges, sanding them smooth. Just be careful not to sand through the fiberglass. Now we’ll roll it over and start glassing the inside.
This is the sixth video of the FRS12 how to build a boat series where we build a plywood boat. We cover installing floor supports and the outer shear bumper. This is the final step before flipping the boat over to fiberglass. These plywood boat plans and more are available for purchase, and come with full size patterns.
How to Build the Boat
We’ve installed our floor supports that are 1×1″ cypress strips. To mark their location we used a straight edge on top of the stringers and transverse frames and marked it with pencil. Then we cut our pieces to size and dry fitted them.
We notched the floor supports so the wood would take the shape easier. The notches are about 1 inch apart and half inch deep. After they were dry fitted, we pull them off, applied thickened epoxy to the back of the cypress strips, then re-installed them using screws from the outside. Don’t worry about the holes, they’ll be covered up when we glass the outside.
Then we clean off all the thickened epoxy off the top and bottom of the floor supports, so it’s easier in preparation for putting our floor down.
How to Install the Shear Bumper
Next we’ll install our shear bumper. I’ve chosen to use cypress, and mine is half inch thick by one inch tall. The first thing you want to do is dry fit the shear bumper. You’ll take the end and set it up at the stem, and without any clamps, you’ll roll it around. I like to start at the front bulk head. Then I’ll work my way back, following the top of the boat. Now that I’ve got it held in two places, I’ll come back and work my way forward.
The plywood can be wavy in an unsupported section, especially along the shear. That’s why we go ahead and install the outer shear bumper. At the front, once you secure it, you’re going to want to stand back from the boat and look at it to make sure the shear bumper is in a fair curve. Chances are, there might be a few imperfections. That’s normal, and if you need to tweak it, and sand down the top, that’s ok.
So once the shear bumper has been dry fitted, we’ll mark where it goes. We’ll pull it apart, and apply thickened epoxy, and clamp it back on. We’ll let it cure before we flip the boat over and fiberglass it.
How to Install a Stem
We installed a stem at the front of the boat to reinforce it. We cut it down to shape and glued it in with thickened epoxy. Whenever we mount a d-ring on the front of the boat, it gives us something to drill in and something for our bolts to bite into.
This is the fifth video in the FRS12 how to build a boat series where we build a plywood boat. We cover how to pull epoxy fillets. This shows how the frames are epoxied to the hull with epoxy fillets and the individual plywood pieces become one large piece. This is where a boat is born! These plywood boat plans and more are available for purchase, and come with full size patterns.
How to Pull Epoxy Fillets
We’ve mixed thickened epoxy and spread it out on the board, because it’s so hot, so it doesn’t cure in the cup. We will pull fillets in between the zip ties. That will hold our boat together, and then we’ll cut out the zip ties.
Once the fillets are pulled (but not cured) we use a putty knife to clean up all the epoxy that pushed out the side and smear it on the board to reuse it.
We pulled the fillets and cleaned it up. Now we’re going to let it cure and cut our zip ties. Then we’ll pull the fillets in between. But first we’re going to pull the fillets in the whole boat, all the way to the front.
All the fillets are pulled, and we’ve cut all the zip ties out, expect for those holding the bottom to the chine.
After You Pull Epoxy Fillets
We supported the keel all the way down the center with a straight 2×4. Then we covered it in plastic (or tape) so the epoxy doesn’t drip down and bond the 2×4 to the boat.
Now we’ve mixed up some thickened epoxy, got a spreader and are going to use the flat side. We’ll use a little pressure as we pull to shove it into any cracks or holes.
We’ve applied just enough pressure so that we’ve pushed the epoxy down into the crack of the wood. This fills the holes, but we haven’t applied too much pressure that we’ve bent it into a full curve. So there is epoxy built up above the plywood. That’s what your glass will lay on. And we’re going to do that all the way from the front bulkhead to the transom.
Let the Epoxy Cure
So after we cut our zip ties and applied our thickened epoxy, our plywood wanted to lift and relax a little bit, not staying in contact with the 2×4 underneath. To ensure we keep a straight keel, we apply a little bit a weight at the keel from what ever we had around the garage, which keeps our bottom on the 2×4 and keeps our bottom straight.
You can build your own boat using our plans and instructional how to videos!
This is the fourth video of the FRS12 how to build a boat series where we build a plywood boat. We cover installing the frames and longitudinal and transverse stringers, which give the boat its strength. These plywood boat plans and more are available for purchase, and come with full size patterns.
How to Install Stringers
We installed our front, middle and rear transverse frames. We glued a piece of 1×1″ cypress to the transverse frames before we installed them which helps keep them straight. And also when we put the floor down, it gives the screws something to bite into.
For the stringers we have left and right. They notch in and we also put a 1×1″ piece of cypress on them and they’ll also notch into the front, which we can secure with a screw.
How to Install the Bow Support Brace
We’re going to install our bow support brace. We put in a piece of wood to serve as a guide. We have it parallel to our front bulkhead and that will give us something to serve as a guide as we push the bow support in.
First, we want to dry fit the bow support, so we have it screwed together with no glue. We slide it in, and it will push the sides of the boat out. We’ll slide it down until we hit the chines. Then we’ll use a level to make sure we’re vertical and use a screw from the outside.
When we remove the guide board we can secure it with zip ties and glue it in, but for now we know it fits. If you need to take a little off, you can pull it out, sand a little off and drop it back in.
You Can Build a Boat!
You can build your own boat using our plans and instructional videos documenting exactly how to build a boat! Check out our plywood boat plans for the FRS-12
We’ll show you how to build a boat using our stitch and glue boat plans!
In the 3rd video of the FRS12 how to build a boat series we cover assembly of the hull using zip ties with the stitch and glue method. This method can be used for other boats and wood working projects.
These boat plans come with full size patterns for you to trace on plywood and cut out.
Before we Stitch and Glue the Boat
We have the pieces for our boat that have already been scarfed and sanded. If they aren’t perfect, don’t worry, we’ll cover them in fiberglass.
We’re going to start at the bottom, at the front. If you lay the pieces flat on a table, you’ll notice an inward bulge. You want to put them tangent to start. After that we’ll line them up and drill holes for the zipties to go through.
To size the drill bit pick one that’s about the same diameter as the width of the ziptie so the ziptie will go straight through the hole without binding up.
How is PVC used in Stitch and Glue Boats?
We also cut small pieces of PVC pipe. As a result, when the zipties go through the hole, the PVC will sit on top to keep the boards aligned. What happens without the PVC is that you’ll put the boards together, work your way down, and one board will slide behind the other, or one will buckle in, or buckle out. We don’t want that to happen. Instead, we want to keep them aligned, so the PVC will hold them in place.
We’ll start in the center, using PVC and a ziptie, and work our way to the front. Once we pull the front together, we’ll go back to the center portion and work our way back.
We finished stitching our keel all the way down to the transom. Then we worked our way down the chines.
How to Stitch and Glue the Boat
The spacing for our holes is about 8″ at the transom, and as we work our way forward into the compound curvature, we’ll go back to 2-3″ spacing. We used 2 or 3 pieces of PVC at the back just like we did at the front to help our wood.
At the end, we’ll grab our front zip tie without drilling any holes in the chine.
We zip tied from the transom up to the front bulkhead. The holes are about 4 inches apart at the front bulkhead, and about three inches at the front.
Don’t zip tie all the way up to the front. We’ll get close and use a zip tie to hold the very front in place without drilling any holes. For the last hole, we’ll grab the bottom and pull it to the side and sandwich the chine, so there’s no need to zip tie it to the chine.
To zip tie the bow together, we’ll use PVC to push our boards apart and at the bottom we won’t need it.
The jig is CNC cut and includes all plywood shown. This center console design is 21’6″ long with an 8′ beam. Her shape is timeless with the iconic custom Carolina flare, proud bow and a raked transom.
We offer stock and custom designs to build your own boat. More information is available on our website.
You can build your own boat using our plans and instructional videos!
In the 2nd video of the FRS12 how to series we cover scarfing plywood using epoxy. This method can be used for other boats and wood working projects.
Boat plans with full size patterns are available for purchase.
Plywood Scarf Setup
We are going to go over how to scarf thin plywood together. To do this, we have a flat, concrete floor. We set up a flat, sacrificial board that is about 8-10 inches wide and is covered with a thin plastic film. This will keep the epoxy from our joint from sticking to our guide boards. We have guide boards in the front and in the back, and they will carry the load of the plywood sheets as we lay them out.
Scarf with Epoxy
First we’ll position our boards and grab mixed epoxy. We’ll use the brush to paint the boards. We’re only going to paint the portion from our mark down, which is the part we’re going to bond. We don’t want to get a bunch of epoxy everywhere else.
We’ll paint one side, flip the other piece over to expose the scarf, and paint it as well. We’ll let that dry. The reason we paint it first is because it is a lot of end grain. The plywood will suck the epoxy into the end grain and dry out the joint if we don’t pre-paint it.
Then we’ll take fender washers and screws – we always use fender washers to keep them from ripping out a hole in the plywood – and fasten them to the board. Use 2,3, whatever you need to hold it flat.
Using Thickened Epoxy
Then, we’ll take thickened epoxy and smear it on our joint area. Because we have plastic down, we’re not worried if some goes over. With the thickened epoxy smeared, we’ll take the next piece, make sure it’s oriented the correct way, and lay it over the bottom piece with the edge very close to the line.
We’ll take a tape measure, or a pre-measured guide block, and measure from the marks we placed when we cut the scarf. These marks should be three inches apart for a three inch scarf. The mark on both side should be three inches. We’ll use more screws to fasten the top piece down.
Let the Epoxy Cure
Then we let everything cure and dry. Don’t be concerned if you have a lot of epoxy to fill up a mistake or a low spot, as long as your dimensions are ok. We’ll sand off anything we don’t need, it will peel off the plastic and we’ll clean up any run-through on the back.
Now you’re ready to build a boat!
This is the first video of the FRS12 how to build a boat series where we build a plywood boat. We cover building a plywood scarf jig and cutting a plywood scarf joint using a router. These plywood boat plans and more are available for purchase, and come with full size patterns.
How to Build a Plywood Scarf Jig
We use a one inch piece of plywood, two 2x4s and a half inch piece of plywood on the sides to create the angle. The center plywood is screwed to the 2x4s and the sides are fastened on an angle. We generate the angle by knowing the length of the scarf is three inches for the 3/16″ thick plywood. We set the sides based on the angle, so we can get a cut that goes from zero to 3/16″.
To find the angle, we can use a scrap piece of wood and measure it, use an angle finder, or if we know the degree that the angle should be, we can use an angle finder with the degrees already labeled on it.
We set the front up at the same height and we’ll raise the back so they are parallel and the correct height.
Using a Router for Scarfing Plywood
We mounted the router to a piece of PVC board, using dissimilar material because they slide better. We used countersunk holes to mount the router.
The height at the front of the jig is also the same height we set the depth of our router bit, so when we touch the router bit to the front of the jig, it just barely touches. When we cut the scarf and pull the router back to us, the router slides up the hill and creates the scarf cut. When we move the router, our wood will have a scarf cut in it.
We will adhere our plywood down with screws and fender washers to ensure the wood doesn’t move. Make sure the fender washers are far enough back that the router doesn’t hit the washers. It could ruin your router bit.
Aligning Wood on the Scarf Jig
Once we have the jig set up ready to scarf, we will align our wood flush with the edge of the jig. We made a three inch mark, for the three inch scarf and have screws and washers holding the plywood down. We have supports off the back of the table to hold the other end of the plywood.
We’ll bring the router and work from top to bottom to cut our scarf. If we make a mistake – we have a bur, so something we don’t like – don’t worry about it. The sander will take care of it, and if it’s a low spot, you can fill it in with epoxy.
You can build your own boat using our plans and instructional videos documenting exactly how to build a boat! Check out our plywood boat plans for the FRS-12