Reply With QuoteI'm going to look in the on-line Afloat web site. Turning rings sounds like just what the doctor ordered!.
Steve
Looking great!
I too have been keeping a close eye on your progress.
As you say, it must be satisfying to see a "boat" appear from flat panels.
I'm going to look in the on-line Afloat web site. Turning rings sounds like just what the doctor ordered!.
Steve
Today we put in a full length re-inforcement layer of fibreglass over then underwater section of each hull. For the techo's this is 400g/sqm double bias glass. The glass is laid on dry and then wetted out with resin. It is then rolled with a steel roller to get out all the air bubbles and ensure 100% contact with the surface. Once fully wetted out, the glass goes clear as you can see in the first picture. In the last picture, we've put a layer of 'peel ply' over the wet-out glass. Peel ply is a nylon taffeta material which epoxy doesn't stick to when it dries. The peel ply draws the excess resin to itself, covers up the coarse weave of the fibreglass, and creates a beautiful surface once it is 'peeled' off.
IMG_0327.jpgIMG_0328.jpgIMG_0329.jpg
I built the transom for the boat this week. The transom consists of 3, 10mm duflex bulkhead panels glued together and then further reinforced around the cutout for the walk-through, and the cutout for the tunnel between the hulls
The first picture shows the 3 bulkheads glued together to form the transom. I screwed through the 3 layers into backing blocks on the opposite side. Then after everything was cured, patch all the screw holes.
The next pictures show the walk-through of the transom routed out to accept reinforcing. This involves replacing 5mm of the balsa “core” with uni glass. The two following pictures show how unidirectional fibreglass is wetted out and rolled up to create 3 reinforcing “sausages.” There are three of these under the walkthrough and 3 over the tunnel.
The last pictures show the sausages laid in the transom and then clamped to squeeze out excess resin and hold the sausages in the tracks while they cure (herding cats comes to mind.) In one of the last pictures the transom is actually standing the right way up, if you look closely, you can see the reinforcing already done for the over-tunnel bit. The final picture show the final look of the reinforcing. The sausages turned black because I used a black marker to draw cutting lines on the fibreglass.
Damn fine work! Really enjoying your progress with it.
Cheers
Chimo
What could go wrong.......................
you are keeping me well educated and im enjoying your thread, great job and ill keep watching.
cheers Jim
Looks as though your getting us to working with the epoxy Steve,a lot more working time with it heading into winter you dont have to rush as much ,looks good, i see you useing the 400 gm db how are you finding it and i see your useing the peel ply its good stuff to use ha,cheers chris.
Last edited by chris69; 24-05-2012 at 09:47 PM. Reason: adding
Yah Chris, It's going good! The DB 400 is really easy to work with: wets out easy, and lays down without a lot of rolling. Also lots of difference when the shed is 16 vs 29 degrees! Now I can relax a bit!. Here's a few more pics installing the transom which I glued in today. Through the miracle of CNC and not me, the transom fit perfectly within +- 1mm all the way round. If you read the post from yesterday, you can now see the uni “sausage” reinforcing is going to do its job. If I turned it over now, it would float!
Next step is to glass this in with 3 layers of the DB 400. 100, 200, and 300mm on each surface, both inside and out. Then install the webs and the mounting boards for the motors.
Hi Steve yer i saw the uni sausage on the transom by the time you overlap the 3layers inside and out it will be tough as ever layer i put in my boat has always gone to the transom i think ive got 5 over laps on my transom seam,ever time you over lap it makes it all stronger especialy when you can get the sheath rolled into the bog fillets when you radius the cornners,you are certinally moveing ahead with it great to see,cheers chris.
Last edited by chris69; 25-05-2012 at 08:40 PM. Reason: adding
Chimo, and Capt Rednut, thanks for the positive notes.Originally Posted by Chimo
Cheers,
Steve
Am loving this build thread Steve. Doing a top job there mate.
What kind of ply sheets are they Steve, the checkerboard looking stuff?
It looks like it would be a pleasure to use, bending wise.
Its not ply Fed its end grain balsa,balsa is very strong when on the end grain and laminated with epoxy.
Thanks Chris I'll look it up.
Hi ya Fed,
Yep as Chris says, end grain balsa which is milled 4" square, then coated in epoxy then sawn to whatever thickness (mine is 10mm,) epoxied side by side, then epoxied between two sheets of fibreglass. Much stronger than plywood but much much lighter and stiffer. You can bend it a little (it's made on the I beam principle) but for a major bend you make saw cuts (kerf) every 2" or so on the inside of the curve. When you got the bend you want, you fill in the kerfs with thickened glue and slap on a layer of fiberglass. When dry it will then hold the shape. Interesting thing about the way it's made, if you do get a hole below the waterline, only a 4" square gets waterlogged.
The company that makes it is ATL Composites, near Brissie. They have a good web site with lots of info. Here's a link that compares, duflex to ply, fibreglass layup, steel and aluminum. http://www.atlcomposites.com.au/file...uflex-foam.pdf
Cheers
Steve
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