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Fiberglassing the Petrel Deck and Hull


At the start of the day I went into the shop and turned the heat up to 80° F (27° C) and made sure the lamp I keep on my epoxy to keep it warm was turned on. This assures the epoxy flows easily.

I rolled the cloth out on the boat about an hour before I started glassing. I could have done it earlier, but I did want to give it some time to warm up to room temperature.

The epoxy was from new bottles with new pumps. I cycled the pumps a few times to get resin into the works. Then I slowly pump to make sure it is being dispensed before I start measuring. I start with the hardener pump and finish with the resin. So long as I always do this I know I will have the correct ratio. The exact amount mixed is not as critical as the ratio. I don't mix up big batches at one time, just enough to fill the mixing cup up about one inch or a couple centimeters. This needs to be mixed throughly.

When I have a level surface, such as the middle of the boat, where I can dump the mixed epoxy, I do so. I want the resin out of the pot and on to the boat quickly. A large thermal mass in the cup will start to cure more quickly than a thin film spread out on the boat, thus getting it on the boat fast gives more time to work on it.

Obviously, more vertical surfaces will not allow the dump-and-spread method, so I use a chip brush to dab on some epoxy and then spread that around. I am not trying to wet out the cloth with the brush, I use the squeegee to spread and saturate the fabric.

I first get the whole boat covered and then go back and inspect for starved areas or missed spots. As long as I work fast this gives me plenty of time to resolve any issues and the resin will still be liquid enough to scrape off the excess into the grunge cup. If I fuss to much with every little spot it will take longer and I might not finish in time to remove the excess. With a little time between the initial application and the inspection some issues take care of themselves and I can see where the wood is absorbing resin and add more as needed.

Note that my techniques here are tuned to the MAS "Slow" epoxy and you experience with other resin systems may suggest alternative methods.