Hey All,
Discovered this forum doing some random Google Searches - seems like just the place I’ve been looking for!
I have some questions and could use some advice, but first I thought I’d share the project I attempted to give an idea of what I want to attempt again. Questions will be listed below the pictures.
Back in 2008, I started a Yamaha Superjet Hull build. I started with the bottom hull plug/mold as I wanted to produce the bottom hull first, as it would require the most time to rig/align motor mounts, plumbing, etc.
I started by building a stable working table the hull would “set in”:
Once majority of the “bodywork” was done on the bottom, time for the flange:
Once the flange was done, time to Duratec the plug and get it finished up. MANY layers of wax, then PVA.:
Here is where it all went wrong (with this project and my house)… but pictures first. Polyester Tooling Getcoat applied, and a couple layers of 4oz glass:
Shortly after this step, before I could start adding more layers of glass to the mold and build it up, I had a pipe burst and took out half my house… After the house was fixed up it was already spring, I had to give up on the project, pull the hull out and get it ready to use for the summer.
I broke the mold pulling it off the plug because of how flexible it was (didn’t matter to me as I would not be using it, and wanted to redo it anyway as I felt like I made to many mistakes already at that point). I also noticed the tooling gel coat had some kind of reaction once the mold was removed.
PICTURES IN SECOND POST DUE TO IMAGE POST LIMIT
What I learned:
[ul]
[li]When applying the gel coat, I should have sprayed, not brushed for a more even coat.[/li][li]When applying the Duratec primer, I should have sprayed instead of brushed/rolled it. Sanding the texture was a nightmare and took way longer then it should have. Also I sanded through many spots and down to the hull.[/li][li]USE BLOCKS WHEN SANDING. DON’T SAND IT ALL BY HAND. My plug turned out extremely wavy once everything was buffed and waxed.[/li][li]USE CHOPPED MATTE for the first couple layers of the mold (after the gel coat). It lays down nicer and contours easier in sharper corners. I had the fabric left in a few spots in the pump area and knew that was no support behind some of the gel coat.[/li][/ul]
So here I am present day and would like to tackle this project again - this time I have a different hull I will be using as a “plug”. My questions / input wanted:
[ul]
[li]The Flange: it took a good amount of time to build the wood flange, bondo/blend, duratec, sand polish. I am thinking of using aluminum duct pieces with foil tape tapped to the hull rails this time around to save a LOT of time. I would still build the wood support flange but lay the metal on top of it for a sturdy backing. I will eventually have to break the flange off to flip the hull over and do it over again for the top half. Thoughts?[/li][li]Polyester or Epoxy: thinking of going the Epoxy route this time for the mold. Once my plug is done and I begin the mold, what would you recommend my first layer be - obviously Expoxy, but specifically what mixture? Use say US Composites Thick 150 Epoxy system with some pigment in it for color? Thoughts? Let’s say right now cost is not the issue.[/li][LIST]
[li]Also, regarding the first couple layers of Matte, chopped Matte will work with Epoxy, but it has binders that will not break down causing it to be a little stiff. Was thinking mix up some Epoxy Resin and Microballons and make all the 90 degree bends have a smoother radius before putting down Matte… thoughts?[/li][/ul]
[li]Polyester w/ Fillers: can polyester resins be mixed with different fillers just like epoxy?[/li][li]What happened?: with my gel coat in the above below?[/li][/LIST]
That is all I have for now. Thanks for your time!
-Andrew
