Friday, May 6, 2011

Glassing Hull #1

Glassing was easier than we thought it would be.

We did a single layer of glass on each side. The plans for the Narai Mk IV call for glass just up to the waterline, or up to the gunwale if desired. We decided to glass up to the gunwale, and to add five layers of glass to the keel, stem and stern post.

For the first side, we experimented a bit. After the first layer of glass, we applied a coat of fairing compound -- micro-balloons. We had read that the micro-balloons could fill the cloth with a single coat. We were not overly impressed with the results. It was quick to apply (approximately two hours for the side), but hard to get even. We ended up with quite a few drips and patches where the cloth clearly wasn't filled.

We roll-coated the second side in the usual manner, putting on two coats so far after the glass.

We intend to roll-coat the whole hull, keel, etc. once the final fairing is done.

Hours for glassing so far:
- six hours per side for the actual application of glass (three people -- one to mix, two to spread)
- two hours for fairing compound on the first side (three people -- one mixer, two spreaders)
- five hours total for roll-coating on the second side (two people -- one mixer, one roller)
- keel, stem and stern post -- approximately five hours per layer (two people -- both mixing and spreading)

Sanding took a total of nineteen person-hours, and now we are ready for fairing compound. For sanding, we used electric orbital sanders, both connected to independent dust collection vacuums.

It's stunning to look inside the vacuums at the end of the day. The filter on one of them (a shop-vac type) was coated with approximately a two-centimetre layer of white, powdery dust. The canister had at least two or three litres of the same powder. The shop itself is amazingly non-dusty after this process. Robbie and Trevor did the sanding, and wore full-face double canister respirators throughout the process. The air in the shop, though, stayed reasonably clear throughout.
Glass taped in place with painters' masking tape
Wetting out the glass

No comments:

Post a Comment