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

[Chotu]

If I have a wire run or hydraulic steering run inside the boat, what do you think is a reasonable way to attach the zip ties or other holders and organizers for the run to the foam cored hull?

I’ve heard a couple conflicting techniques:

1) make a small pad and adhere it to the hull, then use stainless screws to screw the zip tie to the pad

2) just screw right into the hull laminate


This is INDOOR work and not something normally exposed to rain.

What’s your opinion?

[GordMay]

Adhesive Cable Tie Mounting Pads? ➥ https://www.fastenal.com/product/details/0719868

[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

[tkeithlu]

These are really low-load attachments. That's a good job for an adhesive. There isn't really a need for the second step in #1, because adhesive clips like Gord recommends come with wire ties:

https://www.amazon.com/Adhesive-Mana...xpY2s9dHJ1ZQ==

[coopec43]

Originally Posted by Chotu

If I have a wire run or hydraulic steering run inside the boat, what do you think is a reasonable way to attach the zip ties or other holders and organizers for the run to the foam cored hull?

I’ve heard a couple conflicting techniques:

1) make a small pad and adhere it to the hull, then use stainless screws to screw the zip tie to the pad

2) just screw right into the hull laminate


This is INDOOR work and not something normally exposed to rain.

What’s your opinion?

Chotu

You didn't say what sort of foam core? I used Airex Foam core which does not absorb water.

I have used electrical cable PVC Channel (with snap on lids) attached to the inner layup with SS self tappers

[JBP]

The PO of my boat did #2, screwed into interior laminate. While it worked for a while, the inside layer of laminate is very thin and the core offers no screw holding power, and the holes eventually stripped.

[Benz]

Those doodads that Gord showed, glued on with Plexus or a sort of fast-setting marine super-glue whose name I forget are popular around here.

[thinwater]

For stronger attachments, use Weldmount studs or DIY variations.


It's not epoxy, it is methy methacrylate adhesive (MMA), very similar to Plexus MA300 but a little thicker. I don't know it that is OK for you.


You can buy Plexus MA 300 as Locktite Plastic Welder. Most plastic adhesives are epoxies, but this is re-badged Plexus.


From Duckworks:

From Weldmount:

[Jetx]

Originally Posted by thinwater

You can buy Plexus MA 300 as Locktite Plastic Welder. Most plastic adhesives are epoxies, but this is re-badged Plexus.

Thin, you said Loctite, but did you mean Devcon Plastic Welder? I seem to recall the Devcon product being the one discussed in the recent “favorite adhesives” thread.

[Chotu]

Originally Posted by Jetx

Thin, you said Loctite, but did you mean Devcon Plastic Welder? I seem to recall the Devcon product being the one discussed in the recent “favorite adhesives” thread.

There’s a locktite “plastic bonder.” I think he’s talking about that. I looked at the SDS and it says it’s a methyl acrilate so my guess is that’s the stuff. And a wonderful thing to know. Thanks thinwater for that info!!

And thanks to everyone for posting. I’ll try to hunt down some of these adhesive ones. I never really liked putting any holes into the core. I just wanted to make sure I wasn’t wasting time thinking about using adhesive pads.

[rslifkin]

I agree with everyone's adhesive suggestions. The only time I'd put a hole into the core is if I were planning on removing a bit of core around the hole, back filling, and through bolting with a backing plate.

[Luvboats]

Chotu,

Based on your previous posts outlining your severe epoxy sensitivities I would think using mechanical fasteners into the core would be ill advised. I would imagine that you would be using a variety of a coarse threaded wood/sheet metal style fastener and prior to installing these in fiberglass most suggest pre-drilling to avoid fracturing the surrounding material. I would think that this pre-drilling would liberate epoxy/amine contaminated particles to which you would be susceptible, no?

Even if you can work around this concern, I am still in the non core penetrating version of attachment, unless I am doing exactly what rslifkin mentioned above, for what it is worth.

Good luck with your many projects and let us know how they are progressing.

Safe Journeys,
~Jeb

[coopec43]

Originally Posted by Luvboats

Chotu,

wood/sheet metal style fastener and prior to installing these in fiberglass most suggest pre-drilling to avoid fracturing the surrounding material. I would think that this pre-drilling would liberate epoxy/amine contaminated particles to which you would be susceptible, no?

Even if you can work around this concern, I am still in the non core penetrating version of attachment, unless I am doing exactly what rslifkin mentioned above, for what it is worth.

Safe Journeys,
~Jeb

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

[coopec43]

I think for what Chotu is doing (securing a couple of cables to the hull) a cable tie mount is the way to go.

With my yacht I had to secure a dozen+ pairs along the hull and I found the PVC cable channel ideal. I suppose I could replace the SS self tappers with a dob of adhesive but I don't intend to.

[Chotu]

Absolutely correct.

In my case I wouldn’t be pre-drilling since compressing the foam makes for a slightly better bite than pre-drilling.

However, very good point. Why not eliminate all possibility of exposure? Another good argument for the adhesive ones.

I’m thinking of doing home brew ones though. I read the 3m and other sticky ones don’t adhere well to rough surfaces or round surfaces. Mine is both.

So, I’ll get together some small wooden or plastic blocks and stick those on with a better adhesive that lets me fill in the cracks.

Originally Posted by Luvboats

Chotu,

Based on your previous posts outlining your severe epoxy sensitivities I would think using mechanical fasteners into the core would be ill advised. I would imagine that you would be using a variety of a coarse threaded wood/sheet metal style fastener and prior to installing these in fiberglass most suggest pre-drilling to avoid fracturing the surrounding material. I would think that this pre-drilling would liberate epoxy/amine contaminated particles to which you would be susceptible, no?

Even if you can work around this concern, I am still in the non core penetrating version of attachment, unless I am doing exactly what rslifkin mentioned above, for what it is worth.

Good luck with your many projects and let us know how they are progressing.

Safe Journeys,
~Jeb