Tuesday, May 15, 2007

Fairing continues; disaster averted

I wanted to post some more fairing pictures, as a followup from yesterday. Today was a fantastic sunny day in the Pacific NW - generally over 80deg F everywhere, and easily over 85 at my house. I knew I'd be looking at a warm evening in the boat tent, but went out there anyway after work to get started.

But then, as I sighted down the float side that I'm currently working on, I couldn't believe my eyes. There were some humongous bulges and low spots that I just didn't remember seeing before. I'm telling you, this was a serious "What the fudge?!?!" kind of moment; I was panic-stricken for a bit, thinking that the warm weather had melted and deformed my precious float.

I had been delaying the cutting out of my hatch openings, since 1) I don't have the small inspection hatches yet anyway, and 2) this allowed me to sand and fair the decks more easily without the holes getting in the way. It took me about two minutes of frantic thinking before I realized that this was a bad idea since I had neglected to open up any other holes in the float to relieve the pressure. Which explained the bulges in the float. Then I sprinted (okay, walked quickly) for my drill gun. After drilling a nice big 1/2" hole in the middle of the large access hatch areas, both floats hissed and spewed forth hot air for well over a minute. The deformed high & low areas all quickly returned to their original shapes. I hope there's no lasting damage! (And, I have to wonder if this had anything to do with the bubble problem I was experiencing when I was laminating the float exteriors?) Sorry, I did not take a picture of the floats in this condition - it simply wasn't a priority at that moment.

On the bright side, if the floats can hold air under pressure, then I'm pretty sure that they are already water-proof. :) Maybe I'll patent the idea: "Trimaran Float Hull Overpressure Leak Test Methodology using Environmental Friendly Heat Sources". Heh.

After the excitement was over, I got started longboarding again. Here's a couple pictures after an hour or so of sanding:


(The comealong strap is there to hold the aft end of the float down while I was sanding the bow area - the aft end is very light and can easily be levered up into the air.)

It might be hard to tell from the above pictures, but they show significant improvement from yesterday! I am feeling better about the fairing work; it's not easy, but it's not impossible either. Just keep longboarding, fill low spots, repeat. :)

After going as far as I dared with the longboard, I filled the low spots again:

Then I worked on my starboard float deck, using the level to identify the high spots. Same as before, the high spots were over the beam bulkheads, and a slight one over the extra glass for the main access hatch. However I think I'm actually close to being done for this deck -- as another F22 builder mentioned some time back, it's all gonna be covered with anti-skid anyway. I got things to a reasonable level, and then filled the low spots that were still there:

We'll see how it looks tomorrow after I longboard it again. Also, you might notice that I'm not paying much attention to the rounded deck corners -- it's a lot of work to shape those so I figure I will do them last.

Over the weekend I had applied fairing compound to the port deck (the one up on the frames) and did some preliminary sanding, but have now decided to defer further work until that float is in the cradles again -- it's just easier to sand when pressing down, instead of side-ways.

Here's a nice picture (IMO) of my boat tent as seen from the other end:

Now that I'm into some serious sanding, I am very glad that my project is outside -- this much dust would just destroy the garage as well as end up being tracked all over into the house .

Finally, I won't be doing daily fairing updates since so much of the content will be repetitive. I should be doing nothing but float fairing for the next couple weeks at least.


Edward said...

Very interesting about the pressure build-up. I wish you took a picture of it! :)

Never even crossed my mind regarding your fiberglass bubble problem either - I just took it for granted since I had already cut holes in the deck for access hatches.

Tom McCaw said...

That is a great shot of the tent...and it looks like a gorgeous day