Drying out the hull, laying on the tie coat epoxy

Once the hull was sanded- old bottom paint, epoxy, filler, gelcoat, and down to the glass, with all the small surficial blisters exposed- it was time to tent and dry the hull.

I used 6 mil plastic sheeting with 2 x 4's, attaching the plastic using carpet strips and staples. Because it needed to survive the upcoming winter storms, we used lots of duct tape to attach to the hull. - Duct tape comes off after a month leaving a nasty residue, but the residue comes off easily with WD-40 and a rag, and some elbow grease.

We then rented a low temperature dehumidifier, one that has a heating element cycle to melt the ice that forms on the coils, and turned it on full blast for a month between December and January. I washed the hull every few days, to draw out the glycols in the fiberglass.

In conjunction, we used a space heater plus a carpet blower in the tent to keep the air temperature up, and the air flowing.  We measured the moisture content of the hull with a borrowed moisture meter at regular intervals, marking the water content on the hull where each measurement was made, with the date taken.  The moisture dropped substantially, then leveled out, and finally raised slightly again when the last water was drawn out of the hull. This took only a couple weeks, as the hull was pretty dry to start with. I could have probably not bothered with the drying out at all, but as we had taken the trouble to grind the whole hull, we thought it prudent to try.





After a month of drying, it was time to start rebuilding the layers of protection. Bare fiberglass needs a tie coat to Interlux 2000E barrier coat, so we used West System 105 with 205 fast hardener, some foam rollers, and a foam brush to get into the corners, and applied a coat of epoxy to the hull.  We did half the boat the first day, and then washed the dried epoxy with soap and water the next weekend to remove the amine blush that had formed. Then we scuffed the epoxied half with 80 grit sandpaper, and repeated the process to the other half, with a small overlap down the middle.. When the whole thing was dry, we washed the amine blush off again, and scuffed the hull with 80 grit.

The next step was to fill the holes I had ground into the hull to remove all the small blisters. There were hundreds of small blisters that were easily filled with West System 105, using 205 hardener and West System 407 light structural filler, mixed to the consistency of peanut butter. I spent a couple days filling and fairing this. The results of the 16 hours or so spent filling and fairing was well worth the hassle in the long run.

It was important to seal in the filler, so after filling and fairing, I applied another coat of West System 105 with 205 hardener to the entire hull, and then washed the amine blush off and sanded with 80 grit once again. This effectively sealed in the filler in between two layers of West System Epoxy, and prepared the smooth hull for laying on the barrier coat.