mounting a compass...

groundhog · #1 (**permalink**) 10-01-2006

Just bought a Contest 101.
I also bought a tube of 3M 5200, thinking I would need it.

But I looked at the part of the compass that mounts against the vertical cabin surface, I noticed it has a small foam gasket all the way around the circumference.

The foam gasket doesn't look too substantial. I have urges to cream 5200 all over it. Good idea or mistake?

gh

Faster · #2 (**permalink**) 10-01-2006

I wouldn't use 5200 for this job, you'll likely never get it off again if you needed to.

What the manual from Plastimo says is not to use a mastic acetic acid - any sealant that smells like vinegar - which includes many silicones. Use BoatLife or some such caulking instead.

groundhog · #3 (**permalink**) 10-01-2006

Manual?
I got an instruction sheet with the compass that devotes like one paragraph to mounting.
gh

jerryrlitton · #4 (**permalink**) 10-01-2006

You will need a brass screwdriver to make your adjustments.

Jerry

Faster · #5 (**permalink**) 10-02-2006

Groundhog: I got that tidbit off Plastimo's website, where you can get instruction sets in PDF format.

sailingdog · #6 (**permalink**) 10-02-2006

Even a small foam gasket can work quite well, since the compass is generally mounted in a location that isn't going to be all that wet... I'd second not using 5200, it is far too agressive an adhesive, and if you have to remove the compass for any reason, you'll end up destroying the plastic of the compass before the 5200 gives way.

One thing I would recommend highly is that if you have to go through a cored area of the cabintop for the installation...you should pot the installation with epoxy to prevent water that does leak (and it will) from entering the laminate core.

groundhog · #7 (**permalink**) 10-02-2006

When you say pot the installation, do you mean basically sealing the cut edges of the hull by spreading a film of epoxy glue on it?

I usually think of potting as filling up something totally with epoxy or some type of compound.

gh

camaraderie · #8 (**permalink**) 10-02-2006

Over time you may need to remove the compass for LED changeout or fluid addition etc. so silicone is the preferred bedding agent.
Yeah...I think that is what SD is saying...seal the edges with epoxy (not glue) IF they are cored...if it is just glass, don't worry about it.

sailingdog · #9 (**permalink**) 10-02-2006

Yes, but to actually pot the installation properly, you should remove the core from the edges of the hole, and then fill the gap left behind with thickened epoxy. You should also drill the holes for the fasteners oversized, fill them with thickened epoxy and then re-drill the fastener holes the right size, after the epoxy has cured.

As Camaraderie has said, if it is just glass laminate, and no core...don't bother. Most modern boats have cored decks and topsides though...

groundhog · #10 (**permalink**) 10-02-2006

I thought epoxy was glue....