Help making molds for hatches

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Southern Gent
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Help making molds for hatches

Post by Southern Gent »

Let’s plow this field again. I’m starting my mdf hatch mold plugs and Hatch plug too.


2 larger 14” x 60” for rod storage and 2 for battery boxes still working on size.

The build up schedule of fiberglass for each Hatch base with gutter & Hatch braced with marine plywood is my question.

Prep of plug spray PVA or wax release.

I want to use epoxy and correct weight fiberglass cloth or matting.

I keep reading use veil fiberglass?

I read that epoxy resin and matting aren’t compatible?

I will add plywood core to strengthen the hatches.



fallguy1000
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Re: Help making molds for hatches

Post by fallguy1000 »

You can use veil for epoxy if you like. I wouldn’t. Veil is really hard for hand layup-likes to move under following layers.

CSM is advantaged when using polyester as the binders breakdown and it forms easily as such. No help with epoxy.

I recently did some mould work. I used 4 layers of 18 oz glass. Plus 4 on the bottom. The part was a beaching keel. I would tell you two layers is flimsy, 4 is good. If you run 4; after it cures; you could add a single piece to the inside if it was too flimsy.

With the biax; you might need to make corner cuts.
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fallguy1000
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Re: Help making molds for hatches

Post by fallguy1000 »

Okay. I reread. Your post is co fusing. You are making plywood hatches? Or a mould for all glass?

I see. Maybe. So you want to sandwich some 1/4” or 3/8” ply? That would make a backer for screws?

Then y edges are all glass?

Go with 4 layers of 17-18 oz biax.
Last edited by fallguy1000 on Wed Jan 31, 2018 10:55 pm, edited 1 time in total.
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fishgitr
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Re: Help making molds for hatches

Post by fishgitr »

I personally would not use epoxy. It won’t break down the mat like polyester will. Polyester will break it down and make it easier to work with. Within the mat you can use strips of biaxial to strengthen it.

Southern Gent
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Re: Help making molds for hatches

Post by Southern Gent »

Fallguy1000, thanks. Sorry for confusing this. I would like to do all fiberglass
But thought I might need plywood to add support


Let’s separate the base with gutter and Hatch all fiberglass

Hatch. 4 layers 18 oz FG. & add 4 layers 18 oz FG. That should be stiff enough for 14” x 60” hatch

Hatch base with gutter, use as many layers 18 ox FG to build up to 5/16” to 3/8” thickness, should be solid for base.

fallguy1000
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Re: Help making molds for hatches

Post by fallguy1000 »

No need for the extra 4 layers. I was just telling you what I did for a beaching keel. The while boat will rest on it.

Build it with a total if 4 layers of glass. After it cures a few days; not overnite; if you don’t like the stiffness; add a layer to the inside of the cover...

You need edge thickness or it’ll be sharp you know. Four layers won’t be sharp.
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Jeff
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Re: Help making molds for hatches

Post by Jeff »

fallguy1000, Sorry to steal the thread but just wanted to check and see if you received my email (or 2) yesterday? Jeff

Southern Gent
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Re: Help making molds for hatches

Post by Southern Gent »

fallguy1000 wrote: Wed Jan 31, 2018 10:59 pm No need for the extra 4 layers. I was just telling you what I did for a beaching keel. The while boat will rest on it.

Build it with a total if 4 layers of glass. After it cures a few days; not overnite; if you don’t like the stiffness; add a layer to the inside of the cover...

You need edge thickness or it’ll be sharp you know. Four layers won’t be sharp.
Thank you. I think where I got off track was not understanding usage of Polyester Resin and it’s fiberglass cloths , matting, veil etc.

Compared to Epoxy resin and it’s adhesive qualities as used in stitch & glue, with it’s additives to change usage.

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Re: Help making molds for hatches

Post by DAYTRIP »

Southern gent,

My son and I have built about 100 hatch and gutters. On the hatch we do gelcoat-1-1/2 oz mat-1708 biax- aired foam- 1708 biax- gelcoat. On the gutter it is gelcoat- 1-1/2 oz mat-1-1/2 mat-1708 biax. Very strong! Polyester resin.

You can make the mold with mdf and duratec. Once you see how much work it is you can ask JEFF for pricing :D

fallguy1000
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Re: Help making molds for hatches

Post by fallguy1000 »

Are you selling hatches Daytrip?

If so, can you send me a listing?
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