Silicone is truly evil.

[c_amos]

Silicone.

This is truly an evil evil thing. I removed all the hardware from the area surrounding the lazzerette hatch this afternoon. Sadly, it was not bedded in 4200, or even 5200. It was gooped in Silicone sealant.

I know I will have to remove it, and grind all of the gell coat off that has been in contact with it, and then hope foe th best.

The reason for this post is simply to say, for anyone who may not know.

[size=6]Do not ever use silicone sealant on any surface on your boat that will ever need to be painted![/size]

It really does not stick well, and it wicks into the paint/gelcoat and makes it nearly impossible to get paint to stick to anyting in the future!

Thanks for listening. I may be better now

[dasein668]

I find that it actually sticks too well.... but not where you expect it to. I just pulled the old toe rail off my boat and have spent seemingly endless hours trying to get the hellish material off. Yuck.

I second c_amos's plea for no silicone! The stuff has no place anywhere in this world except inside computers...

[ebb]

At best silicone is a form in place high temperature gasket material. That's it. On a boat it does everything else really badly and without forgiveness. Evil!

For a more dispassionate review of alternatives to evil silicone check out

www.bosunsupplies.com

Go to 'knowledge' up top.
'useful info' next - then
'adhesive sealants'


I've just removed the coamings on 338. Like everywhere else: evil silicone. But looks like the dfo merely did the toothpaste onestep and slapped them back on with 2" #14 s.s screws for whatever reason he tookem off. Criminal the way it stuck to the gelcoat where they are mounted and hardly at all to the varnished wood. If you are interested in 'coaming' do the 'search' bar up top here.

The virgin gelcoat exposed by removing the coamings seemed easy to scrape once the original bedding compound and the silicone was pulled off. Don't think that here, anyway, we have to go down to the glass. On 338 there is a slight but noticable concave surface to the molded surface of the boat. It was put there, no doubt, so that the coaming would lie tight with the least amount of crack between it and the deck when screwed on. And also hold a layer of bedding.

The other bedding material under the transparent blobs had the color of fried bacon. Wood should always be bedded with something so that rot won't have a place to start. This is a great place for Dolphinite. a non-adhesive bedding compound. [OR BUTYL] Protects the wood (which should be at least varnished, but better to epoxy here) and helps keep water out of the fastenings and the ancient encapsulated mahogany in there what holds the screws. I think the coamings were originally put on with Dolpinite paste.

I also removed the winch pads. They had never been off the boat. So what was revealed was a snapshot of the day the pads were bolted down on the deck. Wonderful! The larger footprint showed the same translucent bedding bacon colored compound, some in the center still movable - 40 years!. Some Dolphinite back then was pretty evil too. Like pentachlorophenol, something bad, in the formula. It had the reputation that whenever two pieces were put together with this stuff, nothing happened in that joint, nothing.

The winch pad bottoms. themselves, are like brand new. I understand that the Dolphinite on the market today is nowhere as lethal yet has a good rep too for protecting mating surfaces. The winch pads were bolted on with a sinle 5/16" bolt thru the center - plenty of opportunity over 40 years for water to get between the wood and the deck!

Best treat was to see a bit of the original deck there under the winch pads. The antiskid pattern on 338 was not 'basket weave' or 'pyramid'. It was tiny barely separated squares, slightly larger than 1/16" with three miniature cuts or slices in the top surface of each one! Can't hardly imagine what the peeler was on this one that released it from the mold trhe deck was made in. I would have to argue the antiskid was applied to the deck after the deck was on the boat. It must have been high-tech stuff in 1965. It's long gone except for these two archeological prints.

[ebb]

C'amos, G'day,
Think to add, thanks to your banner headline/thread, something you know, but others might not.
That is,
Do not use any solvent (or heat) in the attempt to prep the surface of the evil silicone violated surface. Solvents are drivers, they will end up pushing the oily residue deeper into the porus gelcoat. Mechanical scraping, hand scuffing with nylon pad without heat buildup is the only way. And the caveat to this is the grit of sanding sheets can make deeper grooves into which the silicone oil is forced. What they say.

The oily stain produced by silicone is a general observation by workers. Haven't seen any micro photos of this phenomenon. Ditto sanding surface grooves with silicone deposits. Sometimes this kind of 'knowledge' gets passed from one author to another like rumors. Like it sounds right. It might not be as bad as you've been led to think. And you may have done some of this we're not supposed to do. I have. Therefor test the de-evil-siliconed surface with a daub of good quality 2-part epoxy. Let it set. See if you can lift it off with a metal spatula.

If you can, then more scraping (shaving) is necessary. You find hand scrapers with carbide blades, including shaped ones, in independant hardware stores. BACHO has nice ones for detail, and just got a two inch wide one from Rockler but haven't tried it yet on glass, which is the test.

But if you don't want to mess with the gelcoat. it is possible to have a solution with a mental shift! Instead of attempting to create a surface that adhesive will stick to........ just consider it a bearing surface requiring a gasket. The wood on an A/C shouldn't be glued on, metal fittings neither. They are bedded with the main purpose to keep water out of the thru fastenings. Deadlights would be better served if they compressed a gasket. So, in theory, no prep is necessary at all!

White vinegar for two-part epoxy clean up is a green alternative becoming popular. Perhaps it might be useful as a degreaser/cleaner for rebedding. It is easier to use than Simple Green detergent in the work place.

[mbd]

Uh oh! I could swear Don Casey's book, "This Old Boat", suggested using silcone as a rubber-like gasket when dry mounting and reseating your deck hardware. I used it on my previous boat, an ODay 22 when I upgraded my chainplates...

[ebb]

hiya Mike,
Key word: DRY mounting.
Forming gaskets in place, like on near vertical surfaces, must be an artform in and of itself. I will never be able to do it. But if you are squeezing dry silicone rubber between two immovable objects, it's a gasket. Probably has an effective working life of 50 years, longer than you or me for sure and five times longer than 5200.

Ever hear if those plates are still waterproof?

[mbd]

Lost touch with the new owner, but I'm hoping he's not blasting the PO on some ODay list somewhere!

[Theis]

My understanding is that Silicone is only sealing windows and their frames. Period. I used it on the windows and it works fine. Do not use sulfite as it does not work and will start leaking in a couple years, and be cleaned and replaced with silicone. But silicone is messy stuff, and difficult to both get off the sorrounding window opening (beyond the window frame) and impossible to get of the plastic windows (I guess I should have taped the windows, but didn't).

Don't use 5200 for the fittings if you ever want to get them off. It will take the gel coat off with it (at least that eliminates the sanding). I have had super experience using 5200 as a glue/adhesive that also seals (even when I don't need a sealer - like gluing two rusty cast iron peices together). If I recall, 4200 is a removable version of the 5200.

Otherwise, the word is to use sulfite for fittings, the coaming, etc. I have done that and it works well. No problems and it is long lived.

The problem I have not figured out is that Boatlife products are mixtures of various stuff, and I don't know how their products compare to the 3M and West products which are sulfide, silicone or polysomethingorother (5200).

[willie]

Great reading in GOB nov/dec. issue. What to use where, why, and how come!
Worth the price of the mag.

[dasein668]

I know quite a few people who swear by butyl sealant for their ports and deadlights. Haven't tried it myself, but I may give it a go when they go back in this spring...

[ebb]

Yea! Butyl is civilized caulking. It is caulking, not sealant, not adhesive. Comes in tubes and sheets, so you could actually cut to a pattern and fit it. Elegant. Intricate installation can be completely disassembled by civilized methods.

But if you are paranoid and your parts don't fit good and you feel a need to power your fittings together, and you too chicken to use the real stuff, 5200!, than, of course, squirt on a lower number compound, compromise with the not so macho rubber blubber bummer.

Have you asked your Self just why the COAMINGS have to be GLUED on? No, they don't.
Why would you GLUE your HANDRAILS on? No. they don't. Why would you GLUE your STANCHION BASES on? No, you don't What is it: snit, bad temper, frustration? What ever it is it is overkill. OK? 'Cuse me. And, to remove the compound you get to shell out another couple sawbucks for the chemical RELEASE! Y E A ! Hey. it's the right stuff. Gotcha, baby!

[c_amos]

First,

I hope no one takes offence the red ink earlier in the thread. I do hate silicone though, all the more so after scraping it out from under my combings, grab rails, hatch slide rails....



The reason for this post though relates to your statement about Butyl caulking. Does it sufficiently adhere to the surface to assist in the bonding?

I like it for the grab rails, since they are through bolted. I wonder if it would be ok for the teak boards the hatch slides mount to since they are just screwed from the bottom through the cabin top? I was thinking 4200 there for the additional strength. (Of course, this will eventually be protected by the sea hood anyway...)

The varnish is drying on these parts as I type this, but I prefer the idea of not having to deal with more adhesive if there is no need.



OBTW;
I wish I had caught this the first time you posted it;

White vinegar for two-part epoxy clean up is a green alternative becoming popular. Perhaps it might be useful as a degreaser/cleaner for rebedding.

I 'discovered' it about a month later, after much misery.

[ebb]

g'mornin Graig,
Butyl doesn't adhese too good. It is a rubber bedding material classed as a sealant. It's major contribution to the caulking wars is that it remains flexible, which is where waterproofing comes in. The 'sheet' stuff or sticky tapes you get from auto stores are recomended by New Found Metals, eg, for mounting the inner parts of their ports. The stuff is black so they run a cosmetic bead of something white around the squeezeout areas (Sikaflex 291). S291 is a fast set polyurethane.

I think it is agreed that polyurethanes and even polysulfides loose flexibility over time from UV and boat lotions. So here is where your super adhesive gets leaky. I don't know that I would use tube butyl (comes in colors and white) to bed rails on the cabin. I might try the tapes if they came in white, because you want a 'caulk line' On the rails I wouldn't want to squeeze out any caulk or adhesive I put there.

Might try the approved stanchion base method on the rails which is to spread an even thick layer (GOOD LUCK!) of caulk, mount in place and then semi-cinch the fastenings so that everything is even and positiuoned, let it harden to some degree (some will say partially - others will say all the way) then drive the screrws home, hopefully pulling the rails down so that the caulking bulges. (Sheet or sticky gasket material would be SO much easier.) You will have done some carefull blue taping. Last resort would be to cut the bulge off when you leave the tape on too long. Could look real smart!

If you decide to use tube butyl to mount the rails because of its reputation to always flex, here is a trick I just read about. That is to use O-rings around the fastening holes to avoid squeezing all the sealant out. For that matter, if I had some of the tape which is much more firm than butyl out of the tube, might try doughnuts of that around the screw holes. And finish up with tube butyl or polysulfide.

Might go with 4200 - but polysulfide has a rep for lasting longer exposed, and renewing is 100 times easier.

There are issues mounting the hand rails to the cabin. My guess is that witout elaborate oversized drilling and filling the cabin/liner the rails will always want to move. Injecting epoxygel inside the cabin/liner can't be taken lightly, as that can be even more permanent than 5200! The liner is dimpled and distorted by the screws so you have to decide what level of restoration you want.

For a quick fix I would use polysulfide.
I always think in terms of having to take things apart later, curse of the maintenance man. I think dissimilar materials should be bedded, but that's just me - somebody else wants to glue them together, that's ok too! But I'ld have to be starving to take the job of fixing the leak that is bound to show up.

NFM recommends using a metal spatula heated with a hot air gun to soften 5200 when you're trying to remove it!


++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++

Butyl - which is so cheap - might also be considered to bed the coamings. It would be great if an inexpensive material could be useful on the boat. Cleanup is with not so bloody lethal mineral spirits. Hope someone trys it here and reports.

[Tony G]

Okay-now I'm in trouble...I thought I had scraped all of the silicone off of the cabin last year sometime. Wrong. I only got three of the four ports done. However, I did just jump in with the RO sander the other morning and discovered that shiney $#&*! in between some areas of freshly uncovered primer.

So now that I've ground it in (complete BONEHEAD manuver) what do I do to remove it? Anybody? I'm starting a search tonight to find as much info as I can before I do anything else stupid.

Any help is greatly appreciated.

[c_amos]

Tony,

I am quoting your post from the 'silicone again' thread, here because I think Ebb's post answers your question. Read his advise for testing the surface with epoxy, I think that will work.

Okay-now I'm in trouble...I thought I had scraped all of the silicone off of the cabin last year sometime. Wrong. I only got three of the four ports done. However, I did just jump in with the RO sander the other morning and discovered that shiney $#&*! in between some areas of freshly uncovered primer.

So now that I've ground it in (complete BONEHEAD manuver) what do I do to remove it? Anybody? I'm starting a search tonight to find as much info as I can before I do anything else stupid.

Any help is greatly appreciated.

C'amos, G'day,
Think to add, thanks to your banner headline/thread, something you know, but others might not.
That is,
Do not use any solvent (or heat) in the attempt to prep the surface of the evil silicone violated surface. Solvents are drivers, they will end up pushing the oily residue deeper into the porus gelcoat. Mechanical scraping, hand scuffing with nylon pad without heat buildup is the only way. And the caveat to this is the grit of sanding sheets can make deeper grooves into which the silicone oil is forced. What they say.

The oily stain produced by silicone is a general observation by workers. Haven't seen any micro photos of this phenomenon. Ditto sanding surface grooves with silicone deposits. Sometimes this kind of 'knowledge' gets passed from one author to another like rumors. Like it sounds right. It might not be as bad as you've been led to think. And you may have done some of this we're not supposed to do. I have. Therefor test the de-evil-siliconed surface with a daub of good quality 2-part epoxy. Let it set. See if you can lift it off with a metal spatula.

If you can, then more scraping (shaving) is necessary. You find hand scrapers with carbide blades, including shaped ones, in independant hardware stores. Sandvic has nice ones for detail, and just got a two inch wide one from Rockler but haven't tried it yet on glass, which is the test.

But if you don't want to mess with the gelcoat. it is possible to have a solution with a mental shift! Instead of attempting to create a surface that adhesive will stick to........ just consider it a bearing surface requiring a gasket. The wood on an A/C shouldn't be glued on, metal fittings neither. They are bedded with the main purpose to keep water out of the thru fastenings. Deadlights would be better served if they compressed a gasket. So, in theory, no prep is necessary at all!

White vinegar for two-part epoxy clean up is a green alternative becoming popular. Perhaps it might be useful as a degreaser/cleaner for rebedding. It is easier to use than Simple Green detergent in the work place.