Showing posts with label main bulkheads. Show all posts
Showing posts with label main bulkheads. Show all posts

Monday, February 16, 2015

Aka Brackets


The plans call for four hat-shaped brackets on the back of the main bulkheads to carry the akas. These are simple e-glass structures.  Further structural steps on the akas will keep them from laying flat, so these need to be moulded now.




The green tape shows the designed width of the brackets.  The blue tape is a target area for me to layup.  I made them oversize so that alignment issues and rough edges can be removed.





This shows nine layers of wet glass. I used some 4 oz. plain weave left over from another boat.  There was a small amount of colloidal silica in the epoxy to help fill the weave.  The dark area on the right is where epoxy seeped through the packing tape covering the beam below the layup.






This is a rough trimmed part.  This will be properly trimmed when it goes into the boat.  It would be easier to glue them to the bulkhead on a flat table before going into the hull.   The bracket would block access for filleting the bulkhead to the hull, so it will have to wait.


Task time: 8 hours
Total project time: 490 hours

Monday, November 17, 2014

Inlay of Aka Washers

One of today's small tasks was routing out the bulkhead beams to allow inlaying the carbon plate washers.


The template was made with a 3 inch hole saw.   This was slightly bigger than the 75mm washer and it left a bit of room for glue.  The template was aligned/centered by "stacking" the components.  The G10 tube went in the hole, the washer went over the tube and the template around the washer.



The washer dry fitted.

A flush trim bit removed the material from the beam.   This is another task that an experienced build would have knocked out straightaway, but it took me a little head scratching until I came up with the solution.

Task time: 3 hours
Total project time: 334 hours

Saturday, November 15, 2014

Main Bulkhead Work

I have been trying to do several small projects in parallel.   One of the recent projects are the main bulkheads that are at both ends of the main cabin.   These stations have reinforcing planks where the aka cross beams will bolt through the hull.

The unfinished area in the middle gets cut out of the companionway after the bulkhead is in the hull. Until then, it is an extra bracing support.


The bulkheads are large enough that they came from two pieces of plywood.  After gluing the puzzle joints, I have coated both sides with three layers of epoxy.  The epoxy then got sanded back as smooth as I could get it, so it is now ready for final finishing.

The reinforcing planks will get epoxied to the bulkheads before being placed on the strongback.  The planks were shaped from templates that I had made a few months back.  I recently dry-fitted them to the bulkheads with screws through the back.  This allowed me to get the alignment correct and bore holes for the aka bolts.  The screw holes will get filled with epoxy later.   They will mar the less visible surface of the bulkhead a bit.   The screws will be used to accurately locate the planks when they are slick with glue and to help with clamping.




I left the epoxy coating off of the gluing surface of the bulkheads.  This will give an area for a primary wood to wood bond.  Probably not that critical, but it can't hurt.








The hole through the bulkhead gets a similar treatment to the akas.  A G10 tube is inserted and then there is a 75mm cplate washer that the bolt will tighten against.


Task time: 20 hours
Total project time: 331 hours