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Laying fiberglass overhead
On 17 Mar 2004 09:29:27 -0800, (jsheesley) wrote:
Do you guys have any advice, tips or tricks for laying up fiberglass overhead?
Besides "avoid it like the plague"? Yes, but beware, it ain't a pretty
process.
Let's say you have a foredeck with a rotten, wet core. OK, cut
carefully from below with a Dremel cutting wheel so that you have
(ideally) a single piece of glass "bottom layer". This gets reused if
possible, or used as a template if not.
Grind, cut or pry off all soaked core material. Much of it will drop
on your head, which is why you wear a Tyvek jumpsuit, a hairnet and a
full plastic face shield. You do NOT want old mouldy core, bits of
ground up glass or fresh drops of catalyst in the old eyeballs. Tends
to affect pilotage.
Clean the area with an acetone wipedown. Measure the new core material
and dry fit the piece or pieces. Encapsulate said pieces (if marine
plywood, for instance) with epoxy. Let kick until tacky. Carefully
stick to underside of deck (top layer of glass). Have a prop with a
wax papered tip or end ready to prop into place.
Relax. have a beer.
Make thickened epoxy and trowel into the voids around the encapsulated
piece. Try to fill all voids as much as possible, and here's where
pre-wetted out strips of mat come in handy, acting as "tape" to keep
the thick goo in the groove and not on your face.
Use more epoxy on the cleaned up bottom glass layer you carefully set
aside. Stick to the now-adhered core piece. Leave be until tacky dry.
Add a second, wider layer of wetted out tape over the first layer, the
remaining "underdeck" surround, and the original cut-out. Cover in wax
paper and brace from below, and let it set up.
If you are a stickler, you can fill any little voids from above by
drilling small holes, injecting epoxy, and filling the holes with
something colour matched. Me, I figure if it doesn't flex and I can
step on it and mount cleats in it, it's plenty good.
Hope this helps. It's essentially what Don Casey says in Hull and Deck
Repair, but that's on the boat and I'm not.
R.
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