: Hi,

: I finished stripping my kayak about a year ago now and after a long
: "break" to get my business in order (good luck, but at least I
: have a little more time now :-) I have finally finished sanding my
: 1/8" North Star (a little on the heavy side of 1/8"th, forget
: the exact 1,000th now). And now comes the step that I (like so many others
: before me) have found a little intimidating. I have read about it and I
: think I am as ready as a "first timer" can be ... BUT still it
: is like "concrete day" because once the epoxy is on it's ON! I
: Haven't done epoxy/fiberglass yet, except on the two 25"X18"
: FLAT bulkheads. I've learned somethings from the "practice
: panels" but sure would like to check my last questions now with the
: experienced guys on this board !

Epoxy resin starts to thicken the moment you add hardener. Expecting the syrup thick resin to totally absorb and wet-out the twisted strands of fiberglass cloth and displace all the air is a tall order. This is why epoxy makers produce specialty wet-out resins like Clear Coat which have a thinner consistency. I have used Clear Coat.

I switched back to using System Three’s regular resin for wet-out because I’ve had perfect results with the method I use and the resin cost is much less.

To keep the resin as thin as possible I ; heat my shop, mix resin batches no larger than 6 oz., pour resin into a flat roller tray (slowing down set up) and roll on the resin for a fast application.

Rolling on the sealer coat of epoxy will produce a thin even coating. I only use West System roller covers made for epoxy. These roller covers have 1/8” of foam on them, so they generate less bubbles than any other roller cover. Once your sealer coat is applied tip off the surface with a foam brush to remove air bubbles created by the roller.

Despite the inevitable bubbles created by the roller I like this method better than any other because it creates a smooth uniform coating. I use the “tip off” with a foam brush procedure to also further smooth out any heavy areas of resin and make sure I haven’t missed a spot. The uniformly thin coat applied with the roller allows me to keep boat weight to a minimum. I also have much less sanding to do because rolling on resin keeps my coatings uniform.

When I started working with System Three epoxy more than ten years ago, their tech people were recommending sanding to no finer than 80 grit for maximum adhesion. I’ve noticed that Nick says he sands to 120 grit. I recently called West and System Three’s tech people and they now say no finer than 100 grit. I don’t know what MAS recommends but the best way to find out is to call them. These companies obviously have the most experience and testing on their own products and they offer free advise so why screw around with hear say?

MOST Importantly, make sure the temperature in your shop is falling before you apply the sealer coat, so the resin will be sucked INTO the wood. If the temperature was rising, air in the wood pores will expand and off-gas air bubbles into your sealer coat. Also turn off any overhead lights after you’ve applied the resin since these could heat the surface and cause off-gassing.

Do not sand the sealer coat! If you applied a smooth even coat there is no need. If you try to sand and expose bare wood you will have a different colored blotch in that spot when it’s recoated, so don’t do it!

As soon as your sealer coat is tack free lay out your glass and wet it out. It is still important to work with the temperature falling. The sealer coat will not have closed all the wood pores and off-gassing WILL still occur. Roll on the resin. I start in the hull center working along the keel and establish a diagonal leading edge of wet-out cloth toward each sheer strip. By rolling the resin on the cloth on the diagonal you’ll work with the bias of the cloth and will easily remove any wrinkles. Once I have wet out one half of the hull I squeegee off the excess resin. I cut up plastic milk cartons for my squeegees. This plastic is stiff enough to remove the excess resin, but not so stiff it will take off too much resin or force air into the cloth weave as a stiff squeegee will. You cannot overpower the work with the milk carton squeegee. Wet-out the other half and squeegee.

A second below the water layer of glass must be added over the full hull layer. This allows the edge of the second smaller layer to be feathered (sanded smooth) with the previous one. Whenever you sand a surface the additional layer MUST be added on top. IF you put a smaller piece of glass under a larger layer of cloth a step down in the surface will be created at the edge of the partial layer. If you sand this edge you will cut through the full layer of cloth and destroy the integrity of the hull strength.

The Only time you can put a partial layer under a full layer of cloth is when you will NOT sand the surface. I do this on the INSIDE of a hull where I want to add another layer of cloth for strength. I do not sand the cloth on the inside of my boat except for varnishing purposes.

A couple years ago I was at a show in Michigan and talked with the West System Epoxy representatives there. They said they prefer applying additional glass layers over a previously hardened layer. More excess resin can be removed from one layer of glass when squeegeeing against a hard surface than if you laid up two layers of glass together. I now use this method for additional glass layers. It takes a little more time but is also easier for the novice and reduces the chances for air entrapment.

I have changed my mind on using multiple layers of reinforcement at the stems. I now only use one layer of bias cut cloth on my kayak stems. It is important to use the same wet-out resin and shop temperatures whenever you add cloth to your boat, be it stem reinforcement or exterior seam sealing, if you want the cloth to be as transparent as the rest of your hull.

Fill the cloth weave with 3 coats of regular resin (Clear Coat is too thin for this plus it’s much more expensive to use) by rolling and tip off.

After you’ve added your exterior seams and stem reinforcement sand and feather edges with 80 grit. Watch carefully to prevent cutting into the cloth surface as you sand. The cloth will show up and a fine whitish dot pattern as you start to cut the weave. STOP SANDING! Then I add two more coats of resin. This will fill the scratches of the 80 grit, fill the feathered exposed glass and leave a very smooth resin surface. You will be certain of not cutting into your cloth since you have new resin to sand and will not go deeper into the surface of the cloth. You can sand with 120 on the new resin. Then wet sand with 220 and you’re ready to varnish.

A lot of years and boats worth of experience went into the plans you bought from me. If you follow the information in those plans you will produce a fine boat.

All the best,
Rob Macks
Laughing Loon CC&K