A Gap In Understanding of Cored Construction

[ondarvr]

I meant the core used as the frame.

 

[Chotu]

I'll probably grab a 4x8 melamine sheet for a table this time. I used to have a beautiful 27' long by 8' wide glassing table when I built the boat. Now I'm at a marina finishing up the interior and odds and ends.

 

[Chotu]

I meant the core used as the frame.

Whoops. My post wasn't clear.

I meant what you meant.

Using a more solid strip of whatever around the door as the core. Then regular airex for the rest of the core. Sorry about the confusion.

Meant the same thing you said.

 

[fallguy]

We make flat panels all day long.

Lay out the door on your table with a frame of the desired material, dense foam, wood, PVC, etc, then use the lighter weight foam inside that frame. We make the frame slightly oversized and trim to the correct dimensions afterwords.

Thank you for this post and OP for the original question. It is often easy to overlook the obvious.

I am doing some work with 1" plascore that requires solid edges. Originally had planned decoring, but this is a much better idea. It will require some creativity shimming up my 20mm core for the first layup and a bit of thixo on the other side, but much better than trying to decore big honeycomb as planned. We need solid sides for hardware and I can use scraps of corelite for the work, too.

I am also considering making a glass trim piece in a mould to close any of my 12mm core with biax. A moulded strip of glass seems easier than hand finishing; especially since there is already fairing to be done for bulkhead taping there. I will make the mould from wood with a couple of epoxy or duratec lifts. The trim would be epoxied over exposed core; specifically around door openings. In conventional house building; it would be the equivalent to a corner bead.

 

[redreuben]

If your female moulding you can fill corners with gun roving (unidirectional) until you have enough radius for your cloth, alternatively you can go
cheap and fast by painting in some thickened resin with or without fibre and lay into that.

 

[fallguy]

If your female moulding you can fill corners with gun roving (unidirectional) until you have enough radius for your cloth, alternatively you can go
cheap and fast by painting in some thickened resin with or without fibre and lay into that.

Do you mean separate the fibers and lay them in as eaches? I figured 1208 would work well in a tight mould.

 

[redreuben]

Yes seperate fibres - chopper gun rovings, 3 or 4 passes and lay cloth over top, fills the corner.

 

[redreuben]

I’m talking about sharp minimal or no radius corners where cloth and csm will bridge.

 

[SamSam]

Do you mean separate the fibers and lay them in as eaches? I figured 1208 would work well in a tight mould.

Like you cut some long strands of chopper gun roving or pull some strands out of some woven roving and lay it in the corner length wise. You put enough in so the lamination fabric won't bridge the sharp (inside) corner and leave air bubbles or un-reinforced resin. Sort of like how a putty filet does.

 

[fallguy]

Here is the bead I plan...core is say 14mm wide. Shown a bit more open than real for drawing ease.

Showing the tabbing on the other side. The difference gets faired.

I want a radiused edge, so this is different. You guys are talking about harder edges where the glass strands would help square this off. Mine are door openings and pass throughs in bulkheads mostly where people might get caught by a sharp edge the OP asks about. A few external hull areas as well.

Not sure, but there must be some commercial pultrusions for this sort of thing. Whether they fit well will be the question. But a commercial pultrusion might also answer the OP better.