Best Way to Install NFM Ports in Thin Hull.

[xymotic]

OK, so the boat I bought came with all new Ports from New Found Metals. The cabin is 1/8" steel, and the original ports were installed in solid teak blocks that are about 10x10 by 1" thick. I think the ports are 1 1/4 thick.

I had overdrilled the holes in the steel to accommodate a nylon bearing in an attempt to isolate the stainless from the steel. But now I'm wondering if that's just paranoid?

The PO cracked a couple of the wood blocks getting them out, and now I'm a little perplexed trying to figure out the best way to install these things.

I'm thinking of milling out a backplate out of 1/2" starboard or something, then some insulation and then a 'finish' panel of 1/4" or so???

Or would I just be better off forgetting the insulation and putting in a solid teak block? (If I can even afford to replace the busted ones)

And lastly, I'm curious why NFM wants the trim ring installed with sealant rather than just using butyl everywhere?

[AnchorageGuy]

I'm not sure why you want to isolate steel ports on a steel hull. Use the teak spacers since starboard will not allow anything to stick to it and they will eventually leak. As to the butyl, use all butyl or all caulking, the choice is yours, but IMO butyl is a better bedding. I believe Newfound sells the teak spacers for thin bulkheads and hulls. We installed five new ports from Newfound Metal and posted the install on our Beach House site. Chuck

[David M]

No problem with letting steel touch stainless steel. They are not reactive enough with each other to worry about it. They are also not below the waterline. You can stop any reaction by bedding them well so that oxygen or water does not go to where the two metals make contact.

[Maine Sail]

Originally Posted by xymotic

And lastly, I'm curious why NFM wants the trim ring installed with sealant rather than just using butyl everywhere?

Because they sell black butyl and it tends to bleed if the ports are not seated well... The black can be quite messy.

[S/V Alchemy]

True, but if you dog down a butyl seal gradually (and don't overdo it in the first place), you can trim it with a sharp piece of plastic or even a sliver of wood and get good results. I used grey 1/16th x 1/2" butyl bedding strips. Cost: $5 for enough to only use half the roll.

I've done this job using fairly crude HDPE "stand-off rings" I made in the garage and I've had zero leaks in the pilothouse for the last six months. The rings are crude because they will be buried under insulation and a clean covering. They are glorified washers, really. It took some doing to find the metric hex bolts, however, that fit the outside SS trim ring. I think they were 10 mm.

Read how I did it here: The world encompassed: Bright and butyl full



I remain impressed with NFM's products, price point and service (I had to correct my order once). The biggest part of the job was going from a 9 3/8" hole to 10 5/8", a finicky and small amount of material removal I had to keep circular (except for the notch at the bottom!) I burnt out a grinder before I found the right cutting disk for the job. It's significantly easier to just drill new bolt holes to an existing "stock" hole in the cabin side. Remember to paint all bare metal carefully: you don't want to have to pull this apart in the future to source a streak of rust.