CABIN LINER

[ebb]

sheeeese, ebb shud keep is trap shut.
BUT, Eternabond. Is a new generation double stick mastic/gasket material, so I wouldn't run out and buy it just yet as there will no doubt be others with similar material. The stuff is 'environmental friendly, naturally UV resistant, has a 16 to 35 year life expectancy exposed to weather (1/2 that in the tropics?), 5 year shelf life, pliable, self amalgamates, and can be applied under water.' Can't beat that!
The problem with it is that its bond or adhesive quality is unknown in our marine application. It could be total overkill. Or be worthless. It might have other good uses like under stanchion bases and cleats. And once it gets off the roof it might show up in grey or white color instead of only black.

There are myriad sealing, gasketing foam tapes. They come dry, one side sticky and double stick. The foam comes in many forms, formulas, and densities. Mostly the foam tapes have the glue applied so there can be delamination and the foams can break down. Research imco targets the window glazing industry. Maybe transportation too. Most modern glazing, though, uses channel and extruded foams, few flat tapes. It's a toss up what foam tape might cross over to our low surface energy (polycarbonate) slab-on install on our curved cabin sides.
Haven't found anything yet that'll fry in the sun, boil in the heat, stay sticky
under water pressure with no leaks, and be removable years in the future. There is a lot of polycarbonate in the window glazing industry so that is a good place to keep an eye.

Polysulfide if it was available as a sticky tape that held its thickness well under pressure with no oozing might be the ticket - but it doesn't exist. Using polysulfide to mount any polycarbonate is not possible because the solvents in the rubber attack the polycarbonate. Any tube caulk will get squeezed too thin in a bolt on to curved surface scenario. BoatLife's hybrid answer to marine glazing (the polyurethan/silicone tube goop) could be perfect in a wet gasket form but...

McMasterCarr has black butyl rubber sealing tape* that is used outdoors and is said to be "nonstaining, odorless, paintable - has permanent resilience and elongation properties, won't crack, sag, harden even under severe weather conditions."
It's 1/8" thick and comes in 3 widths. The 1 1/2" comes 16yds for $18.25 (76385A150) I'd guess it could be doubled up if you wished. Haven't used it. One cruiser says he has used this tape* under his chainplates (not on your everyday maintenace list) instead of polysulfide.
He had bad leaks with the poly and just a small one with the butyl. The guy describes his chainplates as moving around alot!

I wonder if the tape can be used in the Ariel's original double frame install?
There just may be not enough surface under the outside frame for the tape to seal good?

The eternal bonding quality of Eternabond bothers me. It could bond too well to the cabin laminate and be a gummy mess like silicone to remove. So it's McMasterCarr's butyl for this fool - can't beat the price - maybe it'll seal under stancion bases too - which really DO move around alot!.......unless somebody knows better.....
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*OK, what I'm describing here is NOT what the skipper used under his chainplates (but what I MIGHT use under the polycarbonate which is exposed to the sun.) He used the Butyl-Coated PVC Foam Sealing Tape which has butyl encapsulated foam, that McMasterCarr mentions "for marine applications". It's operating temp range is lower than the all butyl tape. The cabin and deck can get mighty hot at times. These tapes are narrower. Look it up (75875A663) $10.18, 17yds.
The American Window Glazing Tape Assoc. has to invent a UV gradient system for us consumers. These butyl tapes and most other foam tapes do not mention UV in touting their charms. Or if they do it's never in terms of time.
'Has great UV resist properties guaranteed for 6 months or until the rubber hardens, whichever comes first.'

[ebb]

First test(s)
Got two 50' rolls of dark grey 1" wide DOUBLE-STICK tapes from
www.bestmaterials.com
which is a "discount warehouse" for roofing supplies. I figure that what ever has to spend its life on a roof has to be a candidate for use on a boat. Most products are asphalt. Some have graduated to become rubberized asphalt, and highend epdm and urethanes are being used for membranes. It was from an RV forum, I think, that I first noticed Eternabond. Eternal subject on RV forums are their !^#%*&# eternal leaks.

Eternabond sticks to everything except silicone. My interest in non-tube caulking is that I believe when mounting any kind of flat window or frame to the mildly curved cabin sides on the Ariel we will get hard or 'dry' spots where the caulk is squeezed out to nothing creating possible leaks. Hence: tapes. The assumption is that tapes will hold their thickness under pressure - which may not be the case. Tapes also are a lot cleaner to use than tube goop.

The former coamings on Little Gull were mounted with evil silicone. The area has been minused the rubber with scraping, but no sanding has been done. This became my 'test' area. A section was cleaned and scrubbed with Dow-Corning silicone remover (methylsiloxane), a 2nd section prepped with a potent epoxy solvent reducer, and the third was sanded. Blue Tape used to identify the sections stuck best to the first, ok to the second and hardly at all to the sanded section. Blue Tape is a good quick test to see what's up on any surface.

So, 1" wide tapes represent the width of the caulk I'm interested in. I began unpeeling the ($20 a roll) Eternabond gasket. (1"wide and 1/16" thick.) The side IN has an easily removed clear separator. The idea is to unroll it and press it in place - then remove the top. I left the top paper in place. I tried to bend a piece of this gasket around a corner of a window - the top paper disallows this. If the paper is removed, the material is so sticky that it cannot be worked with. It gets pulled out of dimension, does NOT keep its shape. Eternabond is like chewing gum - but this gum aggressively sticks to the skin, and only if you are lucky can you pull it off. Not my idea of a GASKET. In the form I got it's not a friendly product.

By contast, the other Eternabond product: ($5.25 a roll) "High-Temp Butyl Sealing Tape" (1"wide and 3/32" thick) is the exact opposite. It easily bends around the window corner without changing shape or thickness - sticks, but not aggressively. The slight extra thickness seems right.

The test areas on the coaming seat rise revealed that the miracle Eternabond could not be peeled off from any section. The E. Butyl Tape showed mild adhesion to the solvent prep areas, and came off too easy on the sanded, where the blue tape hardly wanted to stick.

Tried to push the E. gum off with a putty knife. Sticks to the knife, sticks to fingers, sticks to the gelcoat, sticks to self. But it's a disappoinment in that it doesn't stick to self good enough. Nothing is supposed to remove it. Had no trouble at all cleaning it off with naptha. Tested some WM Thinner and Wax Remover (essentially Naptha) and it did just as well cleaning the E. gum off.

My feeling now* about the silicone oil contamination on and in the gelcoat around the windows (and anywhere else) is that the oil is now part of the gelcoat and cannot be removed or neutralized. The gelcoat now has a builtin release agent for any gasket (except Eternabond, and even E. can be cleaned off with naptha). No epoxy is going to stick and I have my doubts about LPU or other eurthanes that have primers that are epoxies. The solution is to remove the gelcoat.

I'm going to go with the nice, docile hightemp butyl tape, see how it goes. Do some butyl longevity studies in Hawaii, French Polynesia, Samoa, places like that. At least taking the windows apart again will not be a federal case. We'll try it. I'll get some of the foamcore butyl from McMasterCarr to check out FIRST. Dang, thought I'd got some....
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* casual glob tests where a dab of epoxy-gel mix is smeared on various suspect sites (around the windows inside) and allowed to set - then a chisel is tapped against the lump - shows no adhesion in shear. The gobs can all be removed wth a lite tap.