Bathroom light fixture replacement

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Blue~Go
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Joined: July 31st, 2014, 1:01 am
Location: 1999 Concourse

Re: Bathroom light fixture replacement

Post by Blue~Go »

kdarling wrote:
So you replaced the entire assembly, right?

Any difficulty removing the original one?
I realize you were asking Scott, but in the spirit of "in case you don't mind more information," I did completely remove my original vent to re-bed it (it had started a slight drip in one corner, which I luckily noticed right away). It was a cinch to remove. It was bedded in a non-butyl type putty tape (hence it was slightly dried out and cracked), and then had the gummy type "leveling" stuff around the perimeter and over the screw heads, RV style. I used a screwdriver bit in a drill to poke into the screw heads and loosen them, after which it was not hard to get the gummy off. Then I used a thin flexible putty knife to slide under the vent flange (I cut up milk jugs into flat pieces and use them between any parts of the tool not under the flange, and the roof to avoid scratching). Popped right out and all cleaned up easily with mineral spirits (ahhhhh, one of the benefits of them not having used silicone or something super adhesive).

I put mine back with "true" butyl tape (not putty tape) under the flange and under the fastener heads. Nothing "around the edge" or over the top of the screw heads (I mean, do you put Neosporin on top of a band-aid or underneath it?). I have removed 20+ year old real butyl tape and had it still be stretchy and doing its job. If that had been used I probably would not have needed to re-bed. However, that said, I have no problem with re-bedding once every 15 years as long as the bedding compound(s) used are easy to clean up and re-do. It's trying to remove failed silicone or 5200 or the like that is ridiculously vexing and takes hours or days :evil:

This is the butyl tape I use. It's the only currently available butyl tape I have found that is just like the 25 year old stuff I still have. Any other I have bought has been completely inferior and more like just putty tape (even if called butyl). This is a boater who got sick of not being able to find any himself and started having it made for him (he has a "one guy" marine business).

http://www.pbase.com/mainecruising/butyl_tape

I see Hamilton Marine is carrying it too now.

http://store.hamiltonmarine.com/browse. ... 63071.html

His tutorial on bedding things is really good. I've done basically the same things on my boats for years and do the same on the Chinook now. (With some minor technique adjustments for things like the vent that have thin/flimsy flanges.)

http://www.pbase.com/mainecruising/rebe ... are&page=1

Best part is that when/if you do have to re-bed (or something breaks; or you just want to put in something different), clean up is a breeze and you are ready to go again.
1999 Concourse
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Scott
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Joined: October 12th, 2015, 5:54 am
Location: Santa Cruz

Re: Bathroom light fixture replacement

Post by Scott »

kdarling wrote:Scott,

So you replaced the entire assembly, right?

Any difficulty removing the original one? (e.g. when I replaced the stock crank antenna with a stationary new one, it was basically a lot of scraping off old waterproofing).

Do you just use butyl tape to waterproof it?

Did it come with a garnish ring?

thanks!
Hey Kev,

This is the el cheapo vent assembly I used:
http://smile.amazon.com/gp/product/B00V ... ge_o07_s00

I’ve purchased and installed two of these so far and I’m satisfied. Both came with garnishes despite the description. The second unit came with decent screws and some low-quality putty tape. I’m going to replace the fan switch with a two dollar potentiometer. Much nicer vent options are certainly available for much more money, but I dislike the shrouded fan in the Fantastic units (despite their better functionality) because they block light and the sky view.

As Blue mentioned, I just used a screw gun and Phillips bit to penetrate the lap sealant and back out the screws. Then used a putty knife to get under the vent flange, pried it up, removed the fan motor for another project, then lobbed the whole unit into the trash. The decades-old putty that Chinook used was still supple and the roof core was bone dry. It all cleaned up with mineral spirits. The hole pattern in the new vent was different so I marked the new hole locations and drilled pilot holes. I puttied the flange, screwed it down just so the putty would creep out a bit, and put a small bead of lap sealant around each screw head (Blue, don’t flame me for using lap sealant!!! :oops: ).

I’ve been using this butyl for various things with great results:
http://smile.amazon.com/gp/product/B001 ... ge_o00_s02

I don’t know if it’s “real” butyl or not, but it’s soft and easy to work with and I expect it to last.

Hope that helps.
1994 Premier
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Scott
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Re: Bathroom light fixture replacement

Post by Scott »

Blue~Go wrote:I put mine back with "true" butyl tape (not putty tape) under the flange and under the fastener heads. Nothing "around the edge" or over the top of the screw heads (I mean, do you put Neosporin on top of a band-aid or underneath it?).
Hey Blue,

I understand and agree with your aversion to lap sealant, and that tutorial you linked to was awesome. However, I think all of his examples of using butyl under fastener heads involved countersunk through-holes and bolts/nuts rather than screws, correct? If the bolt doesn’t spin and the compression is achieved via a nut, then that appears to work brilliantly. But I tried that technique with wood screws and no countersinks (the vent flange is too thin) and the spinning caused the butyl to squeeze out completely once the screw head made contact with the flange. As a result, I had very slight leaking through a few of the fasteners in my galley vent. Once I put a bit of lap sealant around the screw heads, no more leaking.

But I certainly don’t use any goo around the flange. I just wait a couple days to let the butyl to creep out, then clean it up with either a ball of butyl or plastic razor. I’ve done this with two windows, two vents, a skylight, and the upper fridge vent.
1994 Premier
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