Wednesday, September 21, 2011

Getting Better All The Time

After a bit of a rocky start trying to lay down fairing compound so I won't have to spend weeks and weeks sanding I think I've finally figured out a technique that works for me.  It's not so much technique and comes down to practice to be able to lay out a decent layer of delicious white frosting on the decks.  Part of the issue was getting a batch mixed up to the right ratios before it starts to kick without panicking.

Adding the Aerosil after all the Q-cells
When I did the aft deck I thought I'd plan ahead and mix up the Aerosil and Q-cells together in the proper ratio, but for some reason when I did it that way, the mixture didn't thicken up as it should given how much Aerosil I was adding.  I can't be sure, but I think when you mixed the Aerosil with the Q-cells before adding to the epoxy, the Q-cells 'smother' the Aerosil and cause it to lose its thixotropic properties.  Whatever the reason, I ended up adding way to much to the epoxy and nearly ruined the batch.  So I've gone back to the standard method where I add the Q-cells first to get a creamy texture, followed by the Aerosil to stiffen up the batch so it won't run. I know it's ready to apply when my mouth starts watering because it looks so much like yummy white frosting.  I haven't tried it yet, but I'll bet it tastes delicious.

I spent about 3 hours yesterday getting the first coat of fairing compound on the foredeck.  Over half the time was spent with the DeWalt random orbit sander and a pile of 60 grit paper.  I went over the entire area to knock off any major high spots and to provide a good substrate for the epoxy to adhere to.  I also found a few air bubbles along the way that I had to sand/grind out.  They were only about the size of a quarter and didn't extend beyond the top layer of glass (of 3 total).  Once sanded, I vacuumed and wiped everything down with acetone before mixing up my first batch.

Small areas on forward cabin top were easy.
I had to plan ahead a little because of the large area and ended up doing it in 3 batches of 18 oz.  I had enough of the third batch left over to put a second (and possibly final) coat on a few of the small sections of the forward cabin top.  I am really enjoying this part of the process; it's a nice feeling when you lay down a nice smooth trowel of compound with no ridges or ripples;  there isn't a huge pile of grinding dust to make you itch for days; and knowing that each swipe brings me that much closer to finishing this sucka.

I stopped back after dinner to check on the layup and spent about 20 minutes longboarding the cabin top that I had done a few days back.  The good news is that the 2:1 Q-cell to Aerosil ratio is nice for sanding; the 60 grit paper cuts right through it and is very satisfying.  The bad news is that I didn't get the cabintop fair with the first coat of compound.  I'll have to do at least one more coat before I'll be happy, but from what I've read, the big areas typically will need several passes before they could be considered fair enough.  I'll post some photos of that next time.

It's starting to look like a boat again.

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