Reply With QuoteWouldn't the supports catch a bit of water at times Steve?
Coming down bum first off a wave at high speed could put a lot of pressure on them. Will you be wearing your hat while driving, it could make all the difference.
I made up the supports for the duck-bill (boarding platform,) glued them in yesterday and glassed them today. This is an example of kerfing the duflex, bending it, then filling in the kerfs and glassing over the cuts.
Wouldn't the supports catch a bit of water at times Steve?
Coming down bum first off a wave at high speed could put a lot of pressure on them. Will you be wearing your hat while driving, it could make all the difference.
Look great Steve,its easy to just make something up and stick it on,you got to love the composite contrucion and even easyer with the endgrain balsa,cheers chris
Fed, I saw this on a boat that a mate did, 28012011160.jpgand thought the same thing. He hasn't had any problems with his, but just to be sure, I made mine smaller than his and made sure not to extend beyond the line of the chamfer panels (the diagonal ones) As you say, mother nature may modify this for me one day, but if that duckbill goes under water, then I reckon my 4strokes are going to enjoy a bit of water too!
You could always fill in the hollowed out sections, think of the fun you'd have making tapered kerfs.
Many thanks for the thread Steve I'm really enjoying it.
Steve
What motors did your mate hang on that one. Nioce looking rig! What dimensions?
C
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What could go wrong.......................
Hi Chimo,
He has Suzuki 60's and gets a max 29 knots . This is 23' long, 8'2" beam.
The next project is the motor wells. The webs are 25mm ply and the mounting board 2X25mm laminated together. The first picture shows them cut out and saturated with epoxy. Next photo shows them glued and filleted to the transom. I clamped small blocks on to get the webs at the right height and used the offcut piece of ply to centre and square the webs on the cutout.The next step was to drill and round out 1/2" holes for strips of uni to tie the webs permanently to the transom. The uni was glassed over inside and out with 400 double bias. This was followed with three layers of fibreglass at 4,6 and 12inches, inside and out. Once this cures, I'll fair the wells on the inside then glass on the motor mounting board.
Laminating the uni through the hole was a bitch. For the first one, I wetted it out on the table. The instructions show this neatly fanned out on the web and the inside of the transom. However, when you wet it out it sticks together like a soccer team of 5 year olds! For the second one I tried putting the uni through the hole dry, I thought I might be able to fan it out as I wet it out. Problem was I couldn't get the inside of the bundle wet whilst it was in the hole. Took it out re-wet it on the table and ended up with even more spaghetti back on the web.
^ That's gold!sticks together like a soccer team of 5 year olds!
Interesting thread. Keep going. It is looking good.
Could you explain the uni hole a bit more? Is it structural? Is it to hold the transom on better than just normal right angle glassing and knees?
Very interesting Steve i can understand what the uni does in tieing it in once laminated but yer a bit of a pain as you say , you would think that the 3 layers of glass over lapped would have been cerficant and it being bogged aswell,some 12k carbon tow would have made it realy strong and stiffened it up instead of the uni,cheers chris.
Learn and see something new every day. Never done it exactly like that before. Interesting. I think you are right that it should have fanned out the full 180 degrees or more so it then bonds with as much cloth and wood as possible and doesn't bulk/ bunch up. Worries me that when you cut this area back and fair it that you may cut a bit of the strength out unless you build the cloth up a little. No big issue
I've done it before by running fg tapes under butt joints splaying them so inner and outer glass layers are bonded diectly and also through holes in a simlilar way to stop "drumming glass" from inner to outer skin but not in a joint like that.
Credit to you so far . love the updates
PS ya mate has a better shed . Shed envy.
Myusernam, Chris69 and Cormorant,
I had responded to your questions/comments but the response didn't update to here. So here goes again, this time with a better story anyway:
Even though the transom of this boat is made up of 3 layers of 10mm duflex laminated together, anything you attach to the back of the transom (such as the motor wells) is only attached to back of the outside duflex panel AND to the layer of fibreglass on the back of that. A way needed to be found to transfer the weight of the engines etc, through the transom so that the entire transom, and not just the last layer of fibreglass, structure supports the engine wells and the weight of the engines. This is the solution that Craig Schionning of Spirited Designs came up with.
Taking into account Cormorant's comments, I wasn't real happy with my first efforts with the uniglass strands. I stripped the uni strands that I had out of a sheet of uni. The strands were about 2mm in diameter and were easy to work with when dry. However, wetted out the strands all stuck together like a wet rope. When I tried, I could no longer separate the 2mm strands; instead the hundreds of glass fibres that make up each strand tended to separate into angle hair. Getting this to fan out was a nightmare, especially where the bundle exited the 1/2" hole on the web. I really only wanted to fan this out about 45 degrees in the direction of the pull as the web would try to pull off the transom. So as Cormorant suggested I'm not going to grind this down to fair it as it will only remove the reinforcing fibres. Instead of grinding down, I'm going to fill to get it fair. Luckily, it's not that big a surface.
I had completed reinforcing 3 of the four holes through the webs as shown in my last post. Before doing the last one, I went to my local glass supplier looking for a 20-25mm uni tape that would be easier to manage. That I couldn't find but I did manage to find some 25mm uni directional tape in carbon fibre ($9./metre!) So I bought 3 metres and created 5 reinforcing tapes for the last hole.
To make this as strong as possible, I first created a bedding layer of cabosil high density which I spread on both sides of the web, around the rounded section of the transom and on the back side of the transom. I took 5 25mm strips of carbon uni 600mm and wet out all but the last 50mm (which was very useful for getting the bundle through the hole.) The carbon uni tapes laid down very nicely. I put down more cabosil bog between the strips to create a nice level surface then covered the lot with a layer of 400 DB. Here's some pics taken before I bogged between the strips and glassed over.
hi Steve,
Great thread and looks like it will be a great rig for what you want. Please keep us updated and i don't know where in oz you are but would love to come for a look once completed. Maybe us Ausfish guys could do a road trip and you could take us on a fishin trip Steve.
I'm definatley going to do something like this once my life slows done a bit.
Great job and i really would like to come for a look one day.
Now your cooking with gas Steve it looks like you got what you were after and when it is laminated over with your 400gm it will go no were,the carbon will give you many more times the strenght than the uni ever will,cheers chris.
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