Interior Attachments to Foam Cored Hull - Two schools of thought.

[Chotu]

Originally Posted by coopec43

I'm surprise Chotu's has been laid up with epoxy! (Are you sure?)

That’s right. The whole boat is made from epoxy. It’s a resin infused hull and structural cross members, which were then bonded to each other with biax tape laid by hand. Also laid up several areas (like the nose cone) with straight hand lamination. See attached pic of a resin infused structural cross member beam bulkhead getting placed. You can also see my daggerboard trunks getting hand laminated in the background.

That’s the whole reason I can’t go near epoxy anymore. This boat. I mixed every drop of epoxy to make it.

Once fully cured (more than 6 months in 90F or 20C type heat), the amines I’m severely allergic to are fully bonded and gone into the polymer.

However, machining the cured epoxy releases small amounts of the amines again as the polymers are cut by the cutting or grinding tool and this is enough to send me to the hospital.

I have found a workaround or two.

I can happily drill into the boat with the drill in one hand and an outdoor shop vac with a very long hose in the other hand, grabbing every speck of the dust that’s created. Emptying the shop vac is a job for someone else.

I can also have someone help me do an epoxy lamination while I leave the marina and as long as they completely paint over the epoxy with polyester and encase it away from the world, I can return to the boat before 6 months.

[SailingVeracity]

I’ve used the weldmount system and found them versatile, secure and easy to use without compromising the substrate.
http://www.weldmountsystems.com/index.php

[Chotu]

Originally Posted by SailingVeracity

I’ve used the weldmount system and found them versatile, secure and easy to use without compromising the substrate.
Weld Mount - Adhesive Fastening System

That’s a nice looking system.

[rslifkin]

I'm now picturing you installing hardware on the boat in a sealed hazmat suit with an air tank on your back...



I wonder... West Systems mentions mixing epoxy to the minimum hardener ratio for building tanks to minimize the risk of amine leaching (rather than targeting the optimum ratio). I wonder if that (and/or an elevated temperature cure for parts where that's practical) would reduce the amount of time required before you could be near something made from epoxy that someone else has built for you?

[Chotu]

Originally Posted by rslifkin

I'm now picturing you installing hardware on the boat in a sealed hazmat suit with an air tank on your back...



I wonder... West Systems mentions mixing epoxy to the minimum hardener ratio for building tanks to minimize the risk of amine leaching (rather than targeting the optimum ratio). I wonder if that (and/or an elevated temperature cure for parts where that's practical) would reduce the amount of time required before you could be near something made from epoxy that someone else has built for you?

Neat, non-sloppy epoxy work and painting it with polyester lets me come aboard the next day, once the air has definitely changed inside, so that’s the way I do it. Epoxy is only used for structural glass work now, of which there are only the chain plates and longeron mount points at the bow left.

Drill and fills and resin bonding are done with vinylester. All new components are done in polyester or vinylester, whichever is appropriate.

For example, the sail control table, where winches are mounted, will be built in polyester or vinylester and vinylestered in to the floor/bulkhead. Epoxy isn’t as necessary for things that aren’t the cross beams or rig attachment points.

[DougR]

Check out the products made by “click bond” . Used by many boat builders...

[coopec43]

Originally Posted by rslifkin

I'm now picturing you installing hardware on the boat in a sealed hazmat suit with an air tank on your back...



I wonder... West Systems mentions mixing epoxy to the minimum hardener ratio for building tanks to minimize the risk of amine leaching (rather than targeting the optimum ratio). I wonder if that (and/or an elevated temperature cure for parts where that's practical) would reduce the amount of time required before you could be near something made from epoxy that someone else has built for you?

OMG! Just 20 seconds ago I mentioned Gougeon Bros and how they warned against using epoxy for water tanks./ I'll see if I can find it.......

[coopec43]

I just had a quick look and I think this is the article I referred to.


https://www.epoxyworks.com/index.php...nk-guidelines/


I made my tanks out of Polyester and asked the resin supplier if polyester was alright for water tanks and he said NO!. "You go and get advice on experts in coating materials" Eventually I gave the tanks several coats of Crommelin water based bitumen,


Water Based Bitumen Paint: Waterproofing: Crommelin

[PirateFoxy]

Originally Posted by Chotu

I can happily drill into the boat with the drill in one hand and an outdoor shop vac with a very long hose in the other hand, grabbing every speck of the dust that’s created. Emptying the shop vac is a job for someone else.

Not sure how much drilling you anticipate but we have a vacuum that attaches *to* the drill (the drill bit goes through the collection nozzle) made by Milwaukee - intended primarily for concrete work so it has an OSHA table 1 (I think) HEPA filter. Usually around ~$180 but my SO found it for ~$65 on sale and we have an old house so Stealth Lead is a concern so we thought we’d try it. Works very nicely.

The only issue with it is that it is designed for concrete drills which have a second handle that fastens on and the vacuum is intended to fix to that same place, so if you’re using it with a different make of drill you have to get a bit creative about mounting them together.

[rslifkin]

Originally Posted by coopec43

I just had a quick look and I think this is the article I referred to.


https://www.epoxyworks.com/index.php...nk-guidelines/


I made my tanks out of Polyester and asked the resin supplier if polyester was alright for water tanks and he said NO!. "You go and get advice on experts in coating materials" Eventually I gave the tanks several coats of Crommelin water based bitumen,


Water Based Bitumen Paint: Waterproofing: Crommelin

I read that article several times before starting my tank build. When I finish the tank, I've got this stuff waiting to go on as a final coating over the epoxy: https://www.ravenlining.com/products...uatapoxy-a-61/


It meets the NSF standard for tanks 50+ gallons (mine will be about 110), so with everything having adequate cure time before and after coating, plus a good flushing of the tank at first use and carbon filters in the water system, it should produce safe water.

[Boatyarddog]

Originally Posted by marcjsmith

I like option 1 As it gives you some flexibility with either just screwing a zip tie to the block or screwing a zip tie mount to the block

But what about using sika or 5200 or a tape adhesive to stick a zip tie mount direct to hull

Yes I think 5200 is a good adhesive for this purpose and is the fastest way.
For the pad, a piece of a hull cutout, or starboard.

This makes for an easy attachment.

With glass one needs to be sure to size the screw hole appropriately, so as to not break off the screw, with starboard the screw makes its own hole and will not corrode.

Unfortunately, those little adhesive pads let go, eventually.
Boatyarddog

[Boatyarddog]

Originally Posted by Chotu

That’s a nice looking system.

Didn't really look at the formula, but it looks to be a two part compound.
Probably thickened epoxy.
Boatyarddog

[Boatyarddog]

Originally Posted by Chotu

That’s right. The whole boat is made from epoxy. It’s a resin infused hull and structural cross members, which were then bonded to each other with biax tape laid by hand. Also laid up several areas (like the nose cone) with straight hand lamination. See attached pic of a resin infused structural cross member beam bulkhead getting placed. You can also see my daggerboard trunks getting hand laminated in the background.

That’s the whole reason I can’t go near epoxy anymore. This boat. I mixed every drop of epoxy to make it.

Once fully cured (more than 6 months in 90F or 20C type heat), the amines I’m severely allergic to are fully bonded and gone into the polymer.

However, machining the cured epoxy releases small amounts of the amines again as the polymers are cut by the cutting or grinding tool and this is enough to send me to the hospital.

I have found a workaround or two.

I can happily drill into the boat with the drill in one hand and an outdoor shop vac with a very long hose in the other hand, grabbing every speck of the dust that’s created. Emptying the shop vac is a job for someone else.

I can also have someone help me do an epoxy lamination while I leave the marina and as long as they completely paint over the epoxy with polyester and encase it away from the world, I can return to the boat before 6 months.

Chotu, is this the stage of production of your vessel, or an older image?
Quite the project.
Boatyarddog

[psk125]

Don't screw anything through the inner skin of a cored hull. We found this out by having a 2' x 3' section of our hull delaminate because of a cable tie that had been screwed to the inside of the hull of our J/36, under the starboard quarter berth. How could water get in there, you ask? The bundled wires were for the engine controls and gauges. Any splashes leaking in through the cockpit, any condensation or other drips, would be directed by the bunched wires directly to where the screw pierced the hull. Twenty years of this and "Voilà"! Studs with adhesive would have saved me a week's worth of cramped boat surgery.

[thinwater]

Choto:


My bad on Locktite. Devcon Plastic Welder is rebadged Plexus MA300. I was not thinking. AFAIK, most of the other "plastic welder" and "plastic bonder" products at the hardware store are epoxies, which you really do not want!!


I mentioned Devcon because you can buy just a little and because it is fast-cure. The Weldmount MMA is just a little thicker.


I have used both epoxy and Plexus/Weldmount to attach even heavy objects to cored hulls. It is permanent and it is the way the pros and manufacturers do it.



I would not screw in the the laminate. No way.


3M5200 is not good at bonding to metal or plastic, so the mounts will likely fall off over time. I have seen this many times on used boats, after 3-10 years. Same goes for self-adhesive mounts.


I'd look at the Weldmount system, and then imagine DIY variations on the theme if you want or need something different.


I don't know if your sensitivity extends to MMAs. How ever, they do stink and you will still want to wear a respirator inside a boat. They cure fast, so the vapors should be gone in a few hours.