Saturday, March 31, 2007

Bulkhead flanges done

I spent Thursday evening trimming and sanding the deck flanges back, doing prep-sanding for the bulkhead flanges, and finished up the rest of the keel taping on the port float (as mentioned, very easy to do in the upright position):



I do wish I had a smaller sander though -- its very hard to get mine into small spaces like down by the keel joint. That's why you see a layer of putty under the tape in the picture above; the putty smooths out irregularities that are too hard to sand out, but would make the tape lie non-flat if left alone.

For doing the bulkhead flanges, I had been thinking that I would setup the form frames (#'s 5, 7, & 9) back up on the strongback, and then add a mold plate to the top of them (other F22 builders have been doing it this way, can't claim this as my idea). Then I began thinking about what it would be like crawl around in the middle of my strongback while laminating -- did not like that idea. So instead, I did my flanges with the float halves sitting on sawhorses. Each bulkhead had its own mold plate of course, held in place with a strap & comealong.

On Friday evening, I prepared the horizontal mold plates:


...cutting them to a reasonable size and covering them with packing tape. You can't tell in the pictures, but they are cannibalized from a few float frames (just like the Indians and the buffalo - no part of the carcass goes unused). I also prepared the angled mold plates used for the deck flanges:


Today the first order of business was setting up the mold plates on the float:

I really liked the idea of being able to sit on the chair while working, but I didn't seem to have enough scrap lumber laying around to get the float high enough (the chair fit, but I still wouldn't have had room to sit under the float). Also, there's not much room toward the aft of the float -- I was moving that rear sawhorse forward and back all day, depending on which side of the aft beam bulkhead I was working on. So alas, no chair - instead, I spent the day on my knees (ouch).

There is a crapload of laminates to be cutout for this phase of the project. I recommend staying as organized as possible, otherwise it is easy to lose track of where you are.


In some cases, you have eight pieces of glass per bulkhead side. By keeping the glass for each bulkhead side in a pre-counted pile, I didn't have to worry about counting glass layers as I went. (It would be quite tragic to be in the middle of the layup, and start wondering "was that two or three layers on that last bulkhead?")

Here's a fwd bulkhead beam, with just the first two layers of "C" laminate in place:

The angled line on the left is there to guide me later when placing the angled mold plate. Note the scribbled-out angled line on the right - that's right, I almost screwed up and laminated the deck flange backwards. Thank goodness I was double-checking things today; it's easy to get confused (could be just me though).

The fwd and center bulkheads are pretty easy to work on. You want to be careful on the aft bulkhead though....if you were to jerk your head to the side without thinking, you could guillotine yourself on the deck flange. :)

Here I am using hot-glue to place one of the angled mold plates into position:

(Wow, look at the belly on that guy. Maybe he should be building a tugboat instead of an F-boat? :))

The hotglue gun trick works great by the way; I was worried that the glue would not be sufficient to hold the mold plates in position, but they never budged.

Here is an aft beam bulkhead with all glass in place:


One thing I found, was that on the aft bulkhead the 9" angled mold plate does not quite fit if placed in the specified position and angle -- it's too long, and will hit the side of the float. I had not seen any other builders mention this though, and wasn't sure what do (and wasn't willing to lose time by emailing Ian about it). Choices were to trim the length to fit, stand the 9" mold plate up at a steeper angle, or position the bottom of the mold plate closer to the centerline. I chose the first option -- it didn't need much trimming, I think I cut it down to about 7 1/2" before it fit.

Working the glass on the angled mold plates is not difficult, but does take time. There are six pieces of "A" laminate per bulkhead side, for the fwd and aft beam bulkheads. I wet out and placed each piece of glass individually, since on the first beam bulkhead I tried to work a triple-layer of "A" into place and found it to be a difficult task and gave up. Doing it one layer at a time like that, by myself, meant I was up and down a lot today -- I will sleep good, for sure.

5 comments:

Edward said...

I had the same issue with the aft beam angle - had to cut almost 2 inches off it. For some reason I forgot to mention it on my site.. oops :)

Jay said...

No worries, Ed. Thanks for confirming you had the same issue -- thought I was going nuts on that part.

T.McCaw said...

Jay I noticed that your sawblade tilts away from the fence...how do you like that?

Tom

Jay said...

Hi Tom,

This is my very first table saw so I don't have much experience to compare it against, and I'm not much of a wood-worker. That said, I am quite happy with happy with the saw in general, and the left-tilt blade. When I was doing pre-purchase research, it didn't seem like there was a big difference between left-tilt and right-tilt. In practice, my fence is easily movable to either side of the blade, and I've had no problems making any cuts I need to.

Grant said...

I found that on the aft beam bulkheads the MDF I used had to be sanded to thinner dimensions to get the length and angle as specified. I just assumed his model incorporated a mold plate that was thinner.