And grooving with FREDDIE NYLON'S PLASTIC STUDS:
Changed horses midstream [again], assume it is an improvement.
[It's important that the description here won't make much sense
unless it is realized that the window openings were previously prepared
by filling in the surrounding space between cabin and liner with epoxy paste.*]
Thought that 1/4", 5/16"OD, barrel nuts (sex bolts) in 304 and 316 from McMCarr was the way to go to mount slab-on Lexan ports to the cabin sides - no hex heads, nice shiney round heads inside and out.
Had the lexan cut, rounded, sanded, prepped, and drilled with 5/16" holes - matched to 5/16" holes drilled thru to the inside of the cabin where the barrel nuts would be.
BUT then it FINALLY dawned on me that poking machine screws through sticky butyl taped lenses and marrying them up inside with barrel nuts wasn't an option - what would keep them from turning? My arms weren't long enough.
And the nagging problem: how to paint the cabin inside with 50 blingy screw heads poking out around the four lights.....wasn't going to paint over them, was I?
So the natural choice became 1/4" 304 T- NUTS - which also happen to have a 5/16" OD barrel that is 1/2" long but with a 3/4"D flange on one end and really sharp stamped spikes at 90degrees around the perimeter. Not so sexy.
Nasty little buggers...... but could be POTTED WITH EPOXY into the cabin wall.
Found a counterbore from McMCarr (cat.pg.2458 - a short 3/4" bit with a 5/16" interchangable smooth pilot that would, and did, precisely counter-bored the inside 5/16" holes into 3/4" diameter holes.
- drilled out each location stopping the countersink just at the cabin molding!!!Used a sharpie pen to depth mark the bit, and drilled easy-does-it.
At this point plain nutz, prepped EACH T-nut with Dremel sanding disks, scuffing up all reachable surfaces so that the epoxy gel filler had more surface area to stick to. Made up some temporary thread protection by screwing polyethylene** all-thread pieces into each barrel - loaded up each of the 52 fittings with gel using a 2oz syringe (TAP Plastic) and pressed each gooper into its perfectly sized hole.
Was going to use the plastic all-thread pieces to position T-nuts exactly in the hole relative to the cabin exterior - but normal s.s. nuts proved to be too tight to turn onto the plastic.
Cabin sides - previously filled with epoxy goop between the cabin and the liner -
have some variation in overall thickness around the window cutouts. T-nuts with a 1/2" length barrel worked for almost every location (also had some 3/8" barrel length on hand, just in case) - and stayed exactly where they were pressed in wet.
The T-nut flange in almost very hole inside ended up slightly below the surface of the liner inside.
The holes are now disappeared and the surface, faired with goop and 407.
There's NO telltale around the window openings (What stinkun T-nuts?) and there is instead an uninterrupted new coat of white primer.
Will mount Lexan with 1/8" offWHITE butyl tape. Squeeze out is inevitable - and necessary. Controling squeeze-out has to be done by introducing O-rings or washers around each screw as the lexan is positioned for the install. The light bronze tinted lex is clear - the butyl is white - and nearly all O-rings are black or red. Maybe 6/6Nylon washers, which are white. An alternative are 1/16" thick and fairly narrow polycarbonate washers (from McMC) that are clear, more durable, more pricey, and maybe just mo'betta.
Screw length has to be watched. T-nuts are open on both ends.
Could turn them in and run them out the now blind end into the cabin - will try to avoid this as the butyl tape is squeezed to its final thickness.
Each fitting had a piece of plastic all-thread screwed in that filled the entire barrel thread to the bottom of the flange - keeping epoxy out. The plastic studs also provided an indispensable 'handle' for holding, gooping and positioning. And also, screwed all the way into the flange allowed filling the shallow dips inside with epoxy gel. Hard to figure how this ballet is done without these so convenient plastic allthread studs.
Wanted to use a nut on the allthread outside to draw the gooped up T-nut into alignment - wasn't possible.
But it seems the process worked anyway. After epoxy set every piece of plastic backed out leaving clear thread all the i/2" way into the flange and the cosmetic evidence of NO fastenings around the windows inside. The counter bore allowed the T-nuts no wiggle room to move out of alignment. Some are probably out of square - a little. Have to assume Incurable Curmudgeon drilled the original holes square.
Anybody want any virgin sex bolts?
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Don't know if this really wants pointing out.
Recently had a short exchange at an Alberg Fleet breakfast with a new Triton owner who had just epoxy glued his polycarbonate slabs to the cabin sides!
Certainly simple and direct....I think.
Conceivably the immobilized polycarbonate - which is more flexible and gummy than the cabin - could move with heat and cold and stay stuck. If acrylic is used it will shatter, imco, without question. He had visited a circumnavigator's yacht and seen, first hand, lexan lights that were glued on that way - and said to have gone around the world with nary an errant leak....
Only the French can do stuff like that!
If your cabin is 1/4" fiberglass laminate and you cut some holes in it to let the light in....
you might glue some 1/4" polycarbonate over the holes to keep the water out - and hope all movement and flexing will equalize and keep the windows in place.
I still don't think it'll work on any Alberg.... and said so.
The receiving T- nuts potted into the cabinside in the above ap are as immobile as the cabin sides. The 3/8" plastic lens floats on a pad of ever flexible butyl tape.
1/4" PHMS are screwed in through slightly oversized 5/16" holes in the lens with a fat EPDM washer under the head against the plastic. Could almost argue these screws, or rather the plastic lenses, are 'floating' .
Have to hope there is room enough in the thru-holes for the lexan to breathe a little. Maybe no.
I guess we'll have to see what happens.
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* The window openings in the cabin of A338 some time ago had their perimeters filled - the very approximate 1/2" space between the cabin and the liner inside the cabin - with epoxy mishmash.
This fix isolates the window openings from any water intrusion into the liner which exits inside over the shelves at the hullsides in as-built Ariels.
This process consequently stiffens and supports the cabin sides in way of the huge openings. Upgrade has been described here and in other threads.
** Mentally stuck on this material. On going back into the McMC catalog discovered there isn't any polyethylene threaded rod. So it has to be Nylon. Epoxy doesn't stick to this material either. I found the 6' long threaded piece sticking out of a tube in a corner of the shop and just ASSUMED. Easy to cut, of course, but very hard to make it easy to screw into a nut, the end has to be clean and trimmed just right. This material also comes as STUDS in the McMC catalog, Suggest that, if you thunk this single-use method of keeping the threads clear of glue is worth it, you spring for the studs. They easily screw into the T-nutz. 1 1/2" would be my choice.
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