March 2, 2008

Weekend Update

This weekend we fiberglassed the bulkheads. This was a relatively straightforward layup and the final product turned out very well. Using a layer on fiberglass on each side of 1" insulation foam, we were able to manufacture strong stiffeners for Nessie. The follow provides insight to both the fiberglassing process and what we did Saturday morning.

After preparing the foam, fiberglass, peel-ply, breather, and vacuum bag, we laid everything out on a piece of flat plywood.

Jen and Mike in the process of a dry run to double check all the materials were cut to specification.

A few steps were skipped in pictures, but what you see here is the green vacuum bagging being sealed. The epoxy has already been lathered on to the fiberglass and it a few hours, the flimsy materials will become a stiff composite.

Will, Mike, and myself double check the two vacuum bags for holes before activating the vacuum pump. It is important to eliminate holes in the bag to ensure a high pressure be applied to the bulkheads. Luckily, this was a simple layup which made for an easy bagging.

While the vacuum begins to suck out air, Jen and I smooth out the vacuum bagging over the bulkheads. Any wrinkles that appear during the vacuum stages will translate on to the surface of the finished product. Although not always a structural issue, its generally something to avoid.

An aerial view of the largest bulkhead while under the vacuum's pressure. The vacuum hose enters the bag from the top of this picture. It is simply a PVC pipe with holes and covered in the breather material, which is equivalent to cotton fleece.

The other vacuum bag has two other bulkheads within. You can really see the vacuum's pressure acting to squeeze the fiberglass to the foam. It is amazing to feel the strength of the end product.

This is what happens when you have done everything correctly. This displays excess epoxy which has been sucked away from the fiberglass, through the peel-ply. By removing excess epoxy, the vacuum bagging technique provides a more effective final product. It is lighter and less brittle than if it had not been vacuumed.

That's all for now. More next week!

No comments: