The Tongass!
Step 16) Fiberglassing the Hull

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(Click pictures for full size image)

Hanging side panel glass

Wetting out side panel glass
(Click to enlarge)
These two images show the basic process. If you are more of a production builder like Renn, you can roll fresh epoxy onto the boat and then unroll glass onto it as he does ...the "wet method". I, on the other hand, am not a production builder, so I use the "dry method". The dry method allows you to get everything right before you commit the job to epoxy and errors are much easier to fix.

Here are the steps for applying glass using the dry method:

  1. Precoat the wood with epoxy, let cure, lightly sand and wash off with water or ammonia water,
  2. Do what you must to hang or hold the glass in place. Here, you can see my use of blue painter's tape to hold glass on the side of the boat. I remove individual pieces of tape as the wetted region approaches it since the wetted epoxy hangs onto the boat just fine.
  3. Next, start in the middle and working your way to the ends, use a roller to wet out the cloth with epoxy. By starting in the middle, the glass is continually stretched as you go and you will prevent the creation of wrinkles. If they do occur, pulling them out by sliding the dry glass away from the wetted areas works fine.
  4. Starting in the middle again, brush out with a black foam brush to make sure there are no drips and the epoxy is nice and even. If you do spot a dry spot, roll epoxy onto it then let it soak in a bit before brushing it out.
  5. Let cure. If you put the right amount of epoxy into the glass, the weave should be very evident, tight and smooth on the boat, but not whitish (which indicates a lack of resin in the cloth.)

Here we are applying the bottom panel glass. Like Renn, I used 38" wide glass and then followed with a patch over the keel since the Jumbo's greater width requires this. Some folks use 50" or 60" wide cloth and let it overlap from either side. It's your call.

Hints: When putting on the bottom panel glass, it'll tend to lift along the inner edge of the chine flat if you are not careful, and when rolling it down over the chine, it'll pull even more. I found that by wetting out the bottom panels completely, leaving the chines dry for now, worked best. Since the epoxy starts to cure (sticky), it holds in place much better for when you go back over it and wet out the chines. But even with special care like this, it is hard to pull the glass tight enough over the chine to guarantee that you will not create hollows (see below) along the way. On one side of my boat, the glass was from a different manufacturer ...same identical type, but had a different wetting agent in it that caused it to be slightly stiffer. On that side, I created a hollow or two along the chine, but the other side went fine. I like the glass from TAP Plastics in Portland, Oregon the best. Note: I applied extra glass (not shown) to the bottom panels before putting the required 10-oz glass on them. In my case, I used some low cost 12-oz Woven Roving that I got from eBay first, then finished with the 10-oz on top. This worked fine. It required some sweaty scraping to smooth it out and used up an additional 1-1/4 gallons of epoxy (mixed) to do it, but I wanted a bottom that was tough enough for beaching while not requiring a lot of maintenance. This step is certainly not required, but it's just what I chose to do.

Applying bottom panel glass
(Click to enlarge)

Freshly cured glass
Scraping the glass
Tapered, filled, and sanded
(Click to enlarge)
Just like throne work where the job isn't done until the paperwork is done, glassing is not done until it's smooth and transitioned into the rest of the structure nicely. After glassing (first photo), you will have selvage edges and 'snarlies' that need cleaning up before continuing. I use a SurForm to quickly take off the worst and to give it an initial smoothing (edge areas). Then I use a Sandvik carbide scraper (middle photo) to remove selvage edges and to taper them to the hull (be careful not to cut existing glass on the hull). Third, I give the boat a light sanding with 80-grit to remove sharp points and minor non-smooth issues on the glass cloth itself. Lastly, I go back and fill the edge areas with microballon/epoxy to hide the edge of the glass, then I let it cure and sand it nicely (third photo). I do this with each layer of glass before moving on. I work according to the philosophy that you should fair early, and fair often. I've gone the other route (all fairing at the end of the build process) and believe me, it's a lot more work that way! My described method might sound time consuming (it is), but in the long run it'll save you work and produce a nicer product when you are done.

UH OH! Dang!

In spite of your best efforts, you are still likely to produce a few goof ups. The most likely are going to be wrinkles in the glass, hollows along corners (shown), and c) bummed up glassing on corner areas such as where the side panels, bottom panels, and transom meet.

Wrinkles are a bummer since they tend to be too far from the surface to force down, so they typically have to be SurForm'd off and then patched. Hollows are typically close to being flush on the boat, but not always. If you can check the hollow and it's perfectly flush, then you can drill a tiny hole (1/16" or smaller) and inject epoxy into the hollow area to fill it. Adhesive syringes can be had from some hobby stores and some Feed & Seed type stores will carry vaccination syringes with larger sized needles available. In the picture shown, I have a hollow spot that needed a little more than the usual epoxy injection. In this case, the hollow was not quite flush so I first injected it then followed with a couple of temporary staples to hold it in place against the hull. The tie-wrap loops give me something with which to pull the staples back out later (about 12 hours later). The third photo shows the cured repair filled with microballoon/epoxy fairing compound.

A hollow spot
Fixing a hollow spot
Filling the repair
(Click to enlarge)

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© Copyright 2004 Brian Dixon