Tuesday, September 2, 2008
Another piece of deck done...
A hundred degrees and 95% humidity with no wind. I'm pondering doing the side decks from the inside... with a window air conditioner going! It is quite nice working late at night, so long as the mosquitos keep away... They are guerrilla fighters, making surprise attacks as they come to suck your blooood! Difficult to defend from while wearing gloves coated in sticky goo... Slap! "Well that was smart..."
But... it is jump proof. Stiff, and pretty fair. I've got a good bit of fairing work to do yet, but for the most part things are looking up. Next weekend I'll switch over and do the starboard side past the main bulkhead, put down a little paint to keep everything protected from the sun.
Scientific approach to goo usage...
2x4 foot section of deck requires:
10 pumps of epoxy to fill the gap around the perimeter.
40 pumps of epoxy, from filling the gap around perimeter, painting it on to the fiberglass surfaces and balsawood... and mixing up the thickened goo to bed the balsa into on top and bottom surfaces.
Between 15 and 20 to do 2 layers of biax around the edges to fully wet out, and remove the excess.
Between 60-70 pumps. Or between 48 and 56 ounces of mixed epoxy per 2x4 foot section, prior to fairing.
I am using 105 Resin, 206 slow hardener. The Mini-pumps deliver .8 fluid ounces of mixed epoxy (Hardener and Resin) for one full pump stroke from each container.
For a thickening agent, I've been using a mixture of 407 fairing filler and cabosil to bed down the balsawood. Around the perimeter I've been using 403 milled glass fibers and cabosil.
*I used a few ounces more than this, as I ran out of hardener half way through one batch... set it off to the side, and ran out of resin in another. Bummer... Then of course, had to prime the pumps! Sad, but no sense making bubble gum consistency epoxy!
The best weight I've found to hold down the top deck skin... a few 6 gallon potable water jugs! Tall and skinny they put a lot of weight down on a small surface area. Anchors, and half empty paint cans/tool boxes and bottles of antifreeze just don't quite compare any more. (Grin)
If you cut the deck skin loose... make certain that you grind it a little smaller before putting it back down. Otherwise you may find yourself fighting with a corner that jams when you put weight on it. Bad time to have a fire drill. I fooled around with grinding everything before gooing it down, and decided to do both sides at the same time with my grinder. It is fairly straight forward, as the top skin is finishing cloth and mat in alternating layers. For strength of the bevel I would prefer to have a little bit larger lip around the edge than what the circular saw provides... but in the end biax is so much stronger it probably doesn't matter.
When you have the top skin off, do some looking around. I've had a few spots of delamination under the stantion posts, as well as some dry mat (Look for yellow/brown/orange glass) that was not fully staturated when new, no sense making a bond to something weak. Then a little bit of time spent smoothing out the plank lines and high spots makes it lay down flat... My tennis shoes looked almost new after that. (Grin)
I cut my own biax tape, and use a sharp fillet knife on a big piece of plywood. Fairly straight forward, but will be investing in an Olfa rotary knife from the fabric store before continuing. It probably is mis-spent labor, versus buying premade tape...
A tarp with a pole of some sort across the bow with two guy wires running down to the stem head, and a loop for the jib halyard is something I'll be working on... My tarp as pictured was merely a psychological aid! (Grin)
A box fan hooked to the jib halyard so it cannot fly over the side is quite a nice addition on windless days.
Update on Flap Disks: I am still on my first Dewalt flap disk, it has no noticeable wear... I don't think I could get as much done without it, and for sure would be spending a lot more on sand paper. I think I've gone through three sand paper skeet so far on the deck recore. That is it... I am impressed! I'm going to pick up a cheap grinder, as I get the feeling that all this glass dust is not very good for my good one... I hate sacrificing quality tools... sigh.