Wednesday, June 15, 2011

Chipping Away

With the high temps in the low 60's over the past few days, I couldn't allow myself to squander the good layup conditions so I have been carving out a few hours here and there to get some core layed up.  Of course even using my work estimation algorithm 3x + 2.754 where x = my estimated hours, the area around the cockpit has lots of curves, cut outs, indentations, and generally annoying things that cause my progress to go even slower.

When I tore up the mess aft of the cockpit, it appeared that the old recore job had replaced the top skin, the core (with plywood), and at least part of the bottom skin.  Unfortunately, the bottom skin was not very sturdy and appeared to be some sort of matte that was very porous and not particularly strong.  There was also an old deck blower vent from when the boat had an atomic 4 that I didn't want anymore, so I decided it would make sense to reinforce it with a layer of 1708 cloth prior to installing the core.

I left the section directly aft of the locker opening to give a little rigidity to the structure while I was laying up the core.  Otherwise I ran the risk of the entire deck sagging under the weight of the sandbags while laying it up.  I could have reinforced from the underside, but thought that this would suffice (it did). 

After I cut out the cloth, I did the same with the balsa core then taped up all the deck holes from the underside and mixed up a 24 oz batch (16 resin, 8 hardener).  I wet out the deck then the cloth and layed it in.  When I was satisfied that it was fully saturated, I wet out the underside of the balsa and then added Aerosil to the remaining epoxy in the pot and thickened it up to spread.  I layed the balsa in, seated it and then mixed up a 20 oz batch and added Aerosil to make a peanut butter mix that I used to fill the gaps under the existing deck flange and around the balsa.  Finally I covered it all with plastic, followed by sandbags and let it kick.

The next day I went back and cut and ground out the area aft of the locker opening and repeated the same procedure as above.  While prepping this section I pulled the backstay chainplate and made sure that there were no issues with the area where it attaches to the stern.  It appears that the chainplate isn't original because it seems to be a different type of metal and not as thick as the shroud chainplates.  It doesn't look like stainless steel, nor bronze.  I don't know my metals very well, but it almost appears to be galvanized.  In any event, it looks to be in good shape, but I think I will be replacing it to be on the safe side.

Yesterday I only had about an hour (my son set his watch to keep me honest), so I set to work on the starboard side along the cockpit to see how much I could get done.  I ate up a good 30 minutes prepping the area with the grinder and sander to ensure a good smooth mechanical bond to the bottom skin (this area still had the original skin intact). 

Because the winches will be located in this area, I decided to do a solid glass layup on part of it to accommodate the large loads it will be subjected to.  Unfortunately, I'm not quite sure exactly where (or how) I will be mounting the winches - the old winch bases were rotting and I am considering using bronze pedestal bases like these.  So I cut out 6 layers about 2 feet long and cut them to the shape of the area in question.  Next I cut out balsa to fill in the remaining area forward of that.  I laid everything in place to see how it fit and at that point my son popped his head up from the ladder and told me my time was up.  The next few days are going to be busy, but I hope to get this section laid up before the weekend (no work this weekend, going to NY). 

I'm reaching the point where I can break the core job up into smaller manageable pieces that I don't have to spend as much time on.  It also works out fairly nicely because I am doing this after work when the temperature is on the downslope so I don't have to worry about the epoxy outgassing.  Ultimately it may take longer, but given how busy my life is right now, it's tough to block off full days.  With that said, I think if I were able to get one full day in, I could probably get the rest of the core in. 

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