What Material, Aside From Epoxy, Can I Use to Close Out the Core?

[Chotu]

And I’m VERY used to wearing a mask. No problem. LOL

I have to wear an n95 or p100 one when particulate pollution is above 50ppm just to breathe.

I love my forced air respirator. It’s enabled me to work on so many things I’d never be able to. Truth is, without it, I’d have to sell the boat. Especially since there are very few other masks available. Just about all chemicals cause adverse reactions (burning sinuses, dry sore throat, burning bloodshot eyes and some difficulties breathing) now after the epoxy sensitization.

I use the forced air respirator or a p100 if I’m getting sick of dragging the hose through my work.

[MicHughV]

well, I'm plumb outa ideas....but the whole objective here is to stop the upper and lower layers from compressing when you tighten down on a bolt.....so I'm gonna throw out my last suggestion...

you may know by now, that I built my first boat....
when I ordered my mast, it came with this long tube of aluminum pipe...and I didn't know what is was for.....it turns out it was to be used as a compression tube...cut to fit...

ie, when I wanted to bolt...say...a 1/4" bolt thru' the mast, I had to drill a hole the size of that aluminum tube...it was maybe 1" in outside dia....I forget now, with an inside diameter of about 1/2". This tube was cut so that it fit exactly from one side of the mast to the other...outside to outside...and it got inserted into the mast, where I wanted the thru' bolt....ie, rigging tangs, etc....so when I tightened down on the 1/4" bolt, that aluminum tube took the compression load and also spread the load over a much wider area...ie, a 1" pipe vs. a 1/4" bolt...same load, but much larger area to distribute the load..

in the same way, you could insert a short length of aluminum tube, wherever it is that you want...fitted to go from the upper skin layer to the lower skin layer, instead of "pouring" a plug...
the bottom side would then get a large washer or backing plate, and the top side will have the fitting, if the base of the fitting is not big enough, maybe another backing plate under it...

food for thought ???...no epoxy of any kind required....maybe some sealant....not sure if that is a no-no for you, but if not sealant, a rubber gasket or something along those lines....

[kmacdonald]

Originally Posted by Chotu

I’ll probably try vinylester. Just have to be sure there are no amines in the hardener.

Vinylester catalyst is MEKP.

Have you considered epoxy?

[Chotu]

Actually, it’s 25mm/1” balsa. As strong as marine ply in compression. Maybe a little stronger. You can’t compress it. It’s why it was chosen in areas I’m mounting hardware. Very light, incompressible.

The goal here is to seal water out. If for some reason, torquing down like a madman was necessary (it’s not - I also use nylock nuts), I could definitely use a sleeve as you are describing and has been introduced earlier as well.

My primary goal here is to keep water out.

Then we have cutouts for hatches. These may be on balsa OR corecell deck areas.

Those are just huge cutouts you could fit through as a person. How do I close that core out assuming 5lb foam? What can I use aside from epoxy to keep water out there? People usually thicken Epoxy and stuff it in the edge of the cutout after decoring a bit.

[Chotu]

Originally Posted by kmacdonald

Vinylester catalyst is MEKP.

Have you considered epoxy?

I’m glad most of it is. A year ago, researching it, I found some vinylester chemistry that worked a bit more like epoxy.

If vinylester is MEKp, that’s perfect. So long as it’ll stick to the existing epoxy, keeping water out of the core.

[MicHughV]

I don't know if you are allergic to this....but you can buy this " expandable " foam that comes in a cartridge....Home Depot carries it....you blast this in there and smooth it out with a palette knife as it will set up quick...homebuilders use this to seal new windows into place....I used this foam setting up the portholes in my hull...

I'm dredging the bottom of the barrel here, you could also try a really thick paint....??? may require one or two coats...???
I often use paint to seal things, I can paint it on, slop it on, etc...sometimes I use a blowdryer to dry it up quick...

all I can think of at this moment....

[kmacdonald]

Originally Posted by Chotu

I’m glad most of it is. A year ago, researching it, I found some vinylester chemistry that worked a bit more like epoxy.

If vinylester is MEKp, that’s perfect. So long as it’ll stick to the existing epoxy, keeping water out of the core.

Downeast boat builders use "hull and deck putty". Call Mertons. You will talk to someone that really knows, probably the owner.

Merton's Fiberglass & Marine Supply

http://www.mertons.com/Epoxy/polyest...ins/putty.html

[fourlyons]

Chotu, have you considered Resorcinol? Not only is it an excellent adhesive, the only truly waterproof glue, it is easy to work with and cleans up with water. It also will soak, or wick, deep into wood fibers. You can also (per the manufacturer) add fillers to change the viscosity. It's very hard when cured, you could drill and tap it, though I've never seen that tested for strength. There is a low temperature version available as well. About the same price by volume as epoxy.

[thinwater]

Originally Posted by Chotu

Hmmm. This is interesting.

It’s way too foamy but if there were a similar glue that didn’t foam...

Yeah. Way to foamy. No seal. limitied compressive strength.

[Thumbs Up]

Acrylic resin. Have you looked into it?

[Chotu]

Resorcinol and acrylic - haven’t looked into either of these. Thanks for the ideas there.

[Chotu]

Originally Posted by kmacdonald

Downeast boat builders use "hull and deck putty". Call Mertons. You will talk to someone that really knows, probably the owner.

Merton's Fiberglass & Marine Supply

Hull and Deck Putty

The interesting thing about this one is it’s just thickened polyester.

[MicHughV]

in my quiet time I do a lot of artwork...and use artist acrylic paints...I've found that it is remarkable stuff..I've used it to paint odds and ends out doors...it seems to weather extremely well, hardens nicely, flows good, doesn't smell, dries quickly, doesn't crack, ...etc....It might be a good candidate to seal the edges for you...it can be purchased in little tubes for around $4 a color....and small brushes are a dime a dozen....
any art store will carry these....

you can do one little area, let it dry....and see for yourself....a small investment...$4-5, worth a shot in my opinion....

[thinwater]

I would put a call into Plexus. They make a lot of acrylic adhesives used in boat manufacture, but I don't know which would best fit your needs. I've used a few, and they've got smart people.


They are expensive.

[rmhutch59]

What's wrong with just using epoxy?