Nidaplast layup

Hi,

I’m building a non structural bulkhead with a door for a 24ft fishing boat. It’s a flat panel with a recess moulded for a door and I’m planning on keeping the nidaplast back from the door recess by 75mm to allow for fixing hardware.

As it would be very flimsy without a core (as was the panel I removed) I was going to use spare 20mm nidaplast I have.

Couple of questions……

First, after gel coating I’ll have to apply a single layer of csm and let cure. Then I’m planning 2x450csm and lay the nidaplast into it whilst wet. Now at this point should I weigh it down, let cure and then put the final 2 layers on or do the whole layup in one sitting? Just cautious about laminating 4 layers of 450 around the door at once.

thanks

 

I’m a bit confused. It looks like the panels are already placed, so are you asking about table work or working in situ? And a single panel or a doghouse and locker/bench boxes in situ?

The veil layers in nida or any veil covered honeycomb are very thirsty, so you cannot just lay that core down onto gc/csm in a table setup and expect a bond. You must meet the demands of the veil and by curing the gc/csm, you’ll lose chemical bonding.

But it also looks like you plan to work in situ and not on the table, so I’m confused about the stack. For in situ work, you must edge all the exposed nida with a core that can be radiused, about 25mm, then a 10mm radius. You would flip that panel over and wetout the veil and hard edges with resin and laminate the inside up on the table. You don’t gelcoat it because you are still bonding to the other sides, no?

Then you build the box or doghouses and bond the hard edges. Then you wet the core to spec and laminate the outside. Then tabbing, fair and then g/c.

I just don’t fully understand how you expect this to go unless you want to table build all the panels and fix the gelcoats at the end. In that case; you are going to end up doing a lot of fairing with gelcoat.

I admit I am not well versed in the application of gelcoats, but I am well versed in building with veiled honeycomb core, so sorry if my gelcoat knowledge is causing an error in interpretation.

Maybe explain a bit better for forum contributors exactly how you plan to do the work and whether or not these are going to be built as boxes. Typically, the box edges would also be tabbed inside n out, so we are missing some pieces you need to explain better.

I think all your gelcoat work looks like final and not any on the table, but will accept a correction.

 

If I were building boxes and in situ, I’d build all the panels and hard edge n radius the tops. Then I’d laminate all the inside surfaces without gelcoat on the table or deck over plastic, etc.

Then I’d bond everything together and fillet n tab the inside of the boxes. Then I’d tab the outsides of the boxes with 150mm tapes and 100mm tapes and then I’d laminate to the edges of the box and minus 50mm, then fair. Then all the gelcoat work by hand after fairing.

Perhaps the csm layer could be done as part of the fairing; this part is where I fall down in expertise some; sorry. Hopefully, I kick off some dialogue.

 

As for the door, I’m not sure I’d consider a door bulkhead non-structural. The bulkhead carries the door, but I digress. Door mounting usually requires a solid core, but you can worry about that bit.

For me, on table build of the b/h, if you have a very good table, you can g/c and csm, then cure then laminate then core wet the veil and lay all on and weigh it all down. Then finish other side a second day, but I actually really don’t like using veiled honeycoms this way at all and have found the veil layer really needs to be fin rolled well.

So, I would probably do the gelwork all at the end; sorry. I just don’t like the way the stuff behaves without fin rolling. The bonding just setting it down is always **** when you do a lift test. Fin rolling can result in some printing of the honeycomb, so you may want to fair one pass before the csm/gc work, up to you. I think 2x 450 will be okay, but check it before the csm goes on.

Make sure to prewet the veil before any laminating, no matter the method. I hate this part because the stuff tends to drink resin terrible. I recommend using a 6mm paint roller and tray. It is messy, but beats pouring onto the honeycomb and resin running into the combs.

 

That’s just an image of the bulkhead I’m renewing. It will be laid up on a sheet of melamine.

 

I would either use weights or vac and laminate side 2 in a second go, but I also really prefer bonding to veil/honeycomb with a fin roller to eliminate voids. The issue with comb is it doesn’t bond well, another idea would be to run the g/c and csm and then fin roll one piece of glass and flip the entire thing, but that could be hard. Either way, I’d say you are gonna end up with air laying that big panel down; sorry.