Pourable core for FG side wall?

tburke

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I've been working over the winter removing the wet balsa core from under two 27" wide pilot house windows (per side). Windows leaked for 25 years into the vertical 20" of 1/2" end grained balsa core below it. I needed a difficult project to occupy me. I chose not to remove the inner skin for several reasons.

Now I need to figure out how to insert a core into the 1/2" wide by about 28" wide, going down about 20". This 26' boat pilot house has no structural load above like a flying bridge. Just my weight erecting the winter cover. Inserting 7/16' solid Divinycel core will be tricky and blind. Reading some web materials, some offer pourable materials. Some say special foams would work (about 4 to 8 lbs/CF). But even if it was not the rapid expanding type, I would think once it started to expand and slowed the vertical expansion, it would have to expand sideways. Thick strong 3/16" outer gelcoat laminate. Weak 1/8" inner skin. Even if I tried to brace the inner skin, the expansion forces might overcome the bracing.

Any experience out there on this?

Thanks
 

F/V First Team

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Adhesion would be your number one concern here, maybe a closed cell foam that you put in with a wand for home insulation? Get down in there all the way to the bottom, just have to go slow with it though, spray here, let it expand, give it another squirt, etc.
 

steveinak

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how about something like a concrete form, plywood on both sides with a few bolts going through to hold it all together and the plywood should take care of any outward bulging. Once the foam sets up pull the bolts and plywood and all you'll have to do is patch up/cover the bolt holes. Hey maybe even just use stainless wire, like a stitch & glue, to hold the plywood on ?? Yes i'm a simpleton:D but it might just work.
 

tburke

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I have heard of the Seacast transom filler. It won't expand (good) but seems like mostly poly resin with some wood flour, so heavy. Increase the pilot house noise maybe? And I seem to remember from fall that their min. container is quite large ($).
 

Bill

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Do you have pics of the pilot house ? Can it come off? Why does it need core? I would lay it on its side if it's not that big and use gravity.. If not like Travis said there will be no bond if you try to just stick the stuff on there and you will have a lot of channels where water will leak,rot the core again and your done. I would think about going solid glass unless you can turn pilot house on its side..
 

Keelboater

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If the area is only 20" x 28" I think I might look into the 345 Bond-A-Lite from LBI. It is a polyester compound that can be used to replace damaged core. Trowel in place, or in your case, pack it in between the inner and outer skins. Give 'em a call at 800-231-6537 to get their opinion for your application.
 

DMack

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I used NidaCore Pourable Transom Compound that I purchased from Composites One in Bristol, RI to pour a transom. It requires a very clean surface to be able to bond. It's polyester based. I used bolts and plywood C-shaped braces to hold the whole thing together while I poured so it wouldn't bow out. Worked good and is strong as concrete but drillable and sandable.
 
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