Fiberglassing 101

I have had very limited fiberglass experience in my life.  I did build a stitch’n’glue kayak about 12 years ago.  This gave me my first and only experience with fiberglass.  I knew the rudder and centerboard would be a good reintroduction to this incredible material.  I also hoped to learn a few things with these foils that would serve me later as I glass the hull and plank joints. With that as a backdrop, I’ll try to explain what I have learned glassing the foils.   DSC00001This is the leading edge of the rudder.  Notice how the fiberglass doesn’t wrap around and lay flat against the opposite side of the foil.  I cut the glass too short, not allowing enough wrap around to secure the edge fibers from lifting up.  DSC00004 It would have been nice to have a little longer wrap here.DSC00003The trailing edge of the rudder, with its sharp radius was very difficult to wrap.  Try as I might, I was not successful in coaxing this edge to stay down.DSC00005 The good news is that with the Shinto rasp, these edges cleaned up very nicely.  I have bragged a lot about this little rasp, It continues to amaze me.  DSC00002 Leading edge after clean up.DSC00006 Even the flat sides have an almost imperceptibly smooth edge of glass.DSC00007DSC00008 On the second side, I cut the glass about 1.5″- 2″ longer than the edge.  This allowed enough wrap around material to secure the raw fiberglass edge.  I also made a few small cut around the tip to allow the glass to lay flat on the opposite side.  DSC00010 If you drape the glass over the foil and smooth it out with your hands, it seems to almost take the desired shape of the foil.  I also think it helps to let the draped glass stay in this shape for some time if possible.  DSC00009I again cut the glass around the sharp corners for a smooth underside wrap of the glass.DSC00011This second side went much better with regard to the fiberglass wrapping over the edge.  The longer edge proved very effective.  This will in effect give 3-4 layers of glass on all the lower edges.


  1. Drape the glass early, smoothing it with your hands and let it sit if possible.
  2. Make the first epoxy coat very thin for good glass to wood adhesion.
  3. Fill the weave with additional epoxy coat within 8 hours for good adhesion to the glass (remember, you cannot sand the initial thin coat without cutting into the glass, therefor the second coat must be applied within the proper adhesion window of the first coat, approximately 8 hours).
  4. 2″ glass overlap allows for very effective wrapping of glass, even over tight radius edges.
  5. Take your time and enjoy this.  It is an amazing process to behold and experience.

Shaping and Glassing Rudder

DSC00009First order of business was to shape the rudder.  It came with a rather odd looking leading edge near the rudder/head junction.  I chose to reshape this area slightly.  I carried the existing shape of the lower section onto this junction area.DSC00013DSC00007DSC00011I thinned down the trailing edge as well.  I left plenty of material for the rudder up haul line, but significantly softened all edges. DSC00012DSC00007Rudder with first coat of epoxy and glass.   DSC00003Most of the edges smoothed out fine.DSC00002But, some of the edges are a bit too sharp to wrap the glass.  On the next layer, I will leave a longer tail of glass to wrap around and secure.

Shaping and Glassing Centerboard

DSC00002 If you haven’t yet purchase the Shinto saw rasp, now would be a good time.  It worked very well to remove excess squeeze out and general epoxy clean up.  I also used this rasp to begin the smoothing of the foil sides prior to sanding.  I then went to 80 grit paper on my orbital sander.  This made short work of the shaping/smoothing process.DSC00003The bottom half of the above photo shows the stock shape of the foil as I received it.  The top half shows the shape I gave the CB/Head transition.  I felt this would make the glassing process much easier and it looks more natural to my eye.  DSC00004The tapered CB head shape from the top.DSC00016After using a 1/4″ round over bit on the CB head edges, I drilled a 3/8″ hole into the existing uphaul line hole.  The forsner bit held its angle very well on this curved surface.  DSC00020I then took a round rasp and created a depression for the uphaul line to follow.DSC00019I rounded the outer end of the 3/8″ hole to allow a smooth transition between the hole and the haul line depression.  DSC00015Cut glass ready for epoxy.DSC00024 First coat of epoxy on the glass.  DSC00028 I used a flat wooden stir stick as a squeegee to remove excess epoxy.  I was striving for a thin first layer (as not to float the glass off the wood).DSC00027Very happy with how this turned out.  I am going to do all epoxy work with the CB in the flat, horizontal position to help avoid epoxy runs.  After filling this weave with another coat of epoxy, I’ll flip the CB and do the other side.  Tons of fun here folks!!

Glueing up Centerboard

DSC00031 Centerboard notched to hold the 22 lb. plate steel, ready to be glued together.DSC00006 This is the 3/16″ v-notch spreader I am using to distribute the thickened epoxy.  I purchased it at Home Depot for $3.00.  It’s a very handy size.  After rolling unthickened epoxy over all inside surfaces, I used this spreader to distribute the thickened epoxy.  For this glueing application I thickened all epoxy with colloidal silicon.DSC00011 With the Shinto saw rasp, purchased from Duckworks Boatbuilder’s Supply, I have begun to work over the rudder edges glued up last night.  I’ve never seen a more effective tool to shape and smooth than this baby.  Good tools make such a difference.    DSC00008After properly glueing up all surfaces, I dropping in the plate steel, placed bricks along the centerline and added clamps around the periphery.

It feels so good to be moving forward.  Monday, I’ll begin to shape and prepare for the outside glassing of these foils.

Glueing up Weighted Rudder

After waiting nearly 2 weeks for more epoxy to arrive, I’m finally ready to move forward.  This is where I left off with the rudder.DSC00269

This rudder will have 2 lb. of plate steel epoxied inside per Howard Rice’s suggestion, which I feel has much merit.  DSC00007After a couple of hours, my rudder now looks like this.  I used old bricks to press down the center to make sure I had good contact around the plate steel.

DSC00009I was looking for even squeeze out all the way around the edges.  I was very happy to see this even distribution of excess epoxy.

DSC00004DSC00003DSC00010Like many have said, you cannot have too many clamps.

My Construction Steps:

  1. I first coated all surfaces with unthickened epoxy.
  2. I then thickened more epoxy and used a 3/16″ v-notch spreader to evenly distribute this thickened epoxy over all inside surfaces.
  3. I then spooned thickened epoxy around the cutout area and around the plate steel.
  4. I then paired the two surfaces, weighted the center with bricks and clamped the perimeter with soft clamping pressure.
  5. I then spent 30 minutes cleaning up the excess squeeze out around the edges.
  6. I’m now headed to my Swedish backyard Sauna to relax and contemplate glueing up the centerboard.  I love this build project!!  If you are reading this blog and trying to decide whether or not to build a boat…do it baby!

Weighting Rudder & Centerboard

I admire all those who attempt this project from plans only.

For me, even the kit will provide plenty of challenges with my limited time and experience.  Opening the foil kit box, I pulled out beautifully looking pieces of sculpted wood that caused a feeling of respect and admiration to settle down over my little wood shop.  I’m very glad I didn’t attempt to rough these out myself.  DSC00002Many have melted lead to weight these foils.

I wasn’t anxious to pursue this course, as I don’t really have the tools to melt, smelt and pour, so I came up with a different idea.  After poking around a few metal shops, I had Pacific Steel cut me two pieces of plate steel.

  1. 6″ x 21″ x 5/8″ to be used for Centerboard (22 lb.)
  2. 6″ x 2″ x 5/8″ to be used for Rudder (2.0 lb.)

DSC00012Here you see the CB steel plate.

I positioned it as low as I felt comfortable, given the thickness restraints.DSC00013

By following the plywood rings, you can get a feel the how much depth you have to work with.  DSC00014Once I determined the location, I scribed the lines on the inside of the CB halves.

 My intent is to route out each halve by a touch more than 5/16″.  This should nicely encase the 5/8″ plate steel.DSC00027I used my Bosch palm router to cut the outside lines.DSC00026The plunge base offered convenient starts and stops.DSC00028The small 1/8″ router bit took a long time and produced a bottom that wasn’t perfectly flat.DSC00029I used a wood chisel to remove the uneven ridges.

 On the second half of the CB, I used a 1/2″ bit that worked much better and didn’t require any hand work to smooth.  DSC00003I cleaned up the edges of the plate steel with a metal file.  DSC00031Here’s how it looked half imbedded into one half of the CB.DSC00006Now for the Rudder.

Not quite as much room here.  My actual placement of the weight is lower than this photograph shows.  DSC00008DSC00269By tilting the 2.0 lb. weight, I was able to move the weight somewhat more aft than a vertical installation would allow.

 I would have preferred a lower placement, but the 5/8″ thickness didn’t allow it.  DSC00271Finally, make sure you wear a dust mask.

This process kicks up a lot of fine dust that you definitely don’t want in your lungs.  This type of dust mask has worked great for me.


  1. I made all router cuts approximately 1/8″ larger than the plate steel.
  2. 5/8″ seems to be a good thickness given the shape and size of the foils.
  3. The plate steel was quick and easy.  It cost $33.00 total for both pieces.
  4. The shape of the steel made for straight forward router wood removal.
  5. The plywood rings allow for easy placement figuring.
  6. Be aware that routing out this plywood produced several small glowing embers of burning plywood dust that actually burned through the wax paper beneath it and had potential to grow into a full blown fire.  I’ve never had this happen before…so just watch things and be careful.

Now I’m forced to hold and rattle until next week, when my epoxy and fiberglass arrive.  

Shaping & Plugging Mast Ends

First order of business was to cut the mast to length.DSC00168You definitely want to measure twice and cut once.

The plans call for an overall length of 16’4″.DSC00166This could make a right nice pencil holder, and conversation piece. 

DSC00167This is the top of the mast.  After applying thickened epoxy to the top plug, I used electrician’s tape to keep the epoxy from running out.

DSC00175Here is what the top looked like after removing the tape.  You can see that the plug drifted a little inward and has what appears to be a hole at the 3:00 position.

DSC00177I started with the hand plane to create the shape.

DSC00179Once I started shaping, it was easy to see that I did have epoxy all the way around the top plug.

DSC00184The tool of the day goes to the Shinto Japanese file.  I’ve never used a file as effective as this before.

DSC00178There is a course side and a fine side.  I never needed the course side.

DSC00183 DSC00180

With the top looking satisfactory, it’s time to plug the bottom.

I am drilling a 5/8″ hole through the bottom plug to allow air movement inside the mast.  I will pour thickened epoxy into this hole and then after it has set up, I’ll drill out the center with a 3/8″ hole.  This will create a nice epoxy seal around the end grain, while still allowing air movement into the mast.  DSC00164The C-clamp worked well to stabilize the small piece on the drill press.  This piece consists of two 3/4″ pine plugs which have been epoxied together.

DSC00172Bottom plug after drilling out the 3/8″ center hole for air movement.

DSC00186I roughed up the inside for good adhesion.  

DSC00187Bottom plug epoxied into position.  Time to go for a bicycle ride!

DSC00200After the epoxy set up, I couldn’t resist flushing up the end with the chop saw.         I also took the rasp to the outside edges to finish things up.  I’ll now set it aside until I’m ready to sand, epoxy and clear coat the outside prior to rigging.