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!

[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.

[Robert Lemasters]

on my Commander I used a thick weather stripping material that has a sticky side between the coamings and side decks after replacing the old screws with new larger ones.
The strip provides a great water seal, is flexable and is UV and weather proof. There is an automotive stripping for trucks and stripping for homes either will do well; although, thicker automotive may in the long run be a little better.

[CapnK]

I'm with Craig and Robert -

Been digging scraping and cursing silicone-weilding DPO's during the whole refurb of Katie Marie's brightwork. It's on the glass, and worse, even forced into the wood grain of the coamings and parts - which makes getting a good finish with varnish damned near impossible. Haven't yet primed and painted the glass in those areas - I guess I'll be finding out if I got enough of that removed when I start that phase (varnish is going on the wood right now).

Found a bad bit of core, forward port cockpit seat, where the PO had bolted a race car chair in place (he needed it for the stability it provided). That area's drying right now (if the rain will hold off), and will need fixing. At least there was no silicone there.

I had thought about using weatherstripping in place of a sealant (I like LifeCaulk), and had forgotten the idea. Thanks Robert for reminding me, as well as confirming its usefullness.

[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.

[Hull376]

Lots of opinions in this thread. How bout any "results?" I've got to re-bed my dead lights which were last bedded with sillycone. A local RV supply store has sticky butyl rubber tape (1"x3/16"x20ft) on sale. And it is white. So any experience from using this tape on deadlights? I want to avoid using anything out of a tube. The last time I did the job single handed, things slipped and slid around so much before the screws on the frames could be tightened that most of the tube contents were on my body. I think I still have those micro molecules of sillycone oil permanently infused into all 5-7 layers of my skin. Maybe also why I can't seem to hold on to a golf club anymore. But I've noticed that paint clean-up on my hands is very fast. If no experience with tape butyl since these posts, then I guess I'll be a sticky butyl rubber tape guinea pig.

[mbd]

Kent,

No first-hand experience, but I am looking forward to trying it out when I rebed my stanchions.

There is a great website with lots of projects and excellent pics: Compass Marine Project Articles

He uses butyl tape to bed some new portlights here: Installing New Found Metals Stainless Portlights

[ebb]

We certainly done a bunch of rantin-n-aravin about silicone here.
It has its place in the engine room.
There is a hybrid by BoatLife called LifeSeal which by other manufacturers is well thought of. It's not new, been around for 20 years. LifeSeal is a silicone/urethane mix. Supposed to have the best of each and none of the bad.

I've used it on the boat, but it is untested. Its ability to stay attached to surfaces and, most of all, to stay flexible for 20 years in the tropics I have yet to witness.
I check the forums every now and again but most can't yet make the distinction between LifeSeal hybrid and BoatLife LifeCaulk polysulfide. It is Boat Life's fault in keeping the confusion going.
Professionals use Bostick products who have customed the hybrid for specific uses. Like one hybrid for caulking teak and synthetic decks and another that resists squeezeout for bedding stanchion bases and portlights.
[Adding to the confusion is exampled by BoatLife selling a 'marine quality silicone sealant' under their own label. Doubt there are cautions about its use around a boat on the tube. I think this irresponsible. And is a major reason I steer away from their products.]
Would think that Sika and 3M have their versions.

So there is a 'silicone' product that could be used if you want to pay for it.

Imco most of our aps can't really use a wet caulk successfully. Bostick's hybrid silthane for mounting stuff has body built into it, forget the term they use. LifeSeal has only the one tube, I believe. If you don't have a thick hard-to-squeeze goop there's no gasket quality. If you got metal to fiberglass you going to leak even tho you put $5 of rubber there.


SO, butyl IS THE WAY TO GO.
If you use butyl tape you don't have a mess.
If you have a difficult surface you can augment with tube butyl. IT's very sticky, so I believe you can get as good a seal as with the adhesives: polysulfide and polyurethane. You are just not gluing your fitting in forever.
And maybe having it leak anyway.
You have to learn how to use butyl. If you have something like a portlight that always requires rebedding then use butyl bedding not adhesive. Most cruisers use butyl I believe for portlight frames. Haven't heard any grousing about it - but then most forums are not set up for follow-through on a subject.

Butyl will always stay soft (pliable) and sticky. Polysulfide can get hard and start cracking in a couple years, depends where you are located.
I don't doubt that butyl can give up the ghost but it's a piece of cake to take the fitting or whatever apart and rebed it. You know it's something you can do, not something you want to avoid.

That's my take on Butyl. The tape and tube are inexpensive. I'll bet their storage life is 10 times longer than tube polysulfide. Means we can have it in the bosun's locker, always available.


I have a Marelon seacock that's going in on 1/8" b.tape. I'll use tube b. on the thruhull flange and in the bolt holes. Underwater, I know, but if it leaks I can redo it OR clean it off with Stoddard solvent and zapp it with polysulfide.

I'll have lexan windows bolted on over butyl tape. It bends nicely around curves. I can see the method (simplified) as stick on the tape, locate the fastening holes, put the fixture in place, poke the fasteners thru with a bit of wet butyl. With a seethru material like lexan dry spots will be noticed. I'm thinking that a dry surface could be primed by pre-smearing wet butyl on it to help get 100% contact? That's an idea for now.

[Hull376]

Mike,

Thanks for the tips on the site. I guess it doesn't take a lot of work to clean up or re-do a butyl tape installation if it doesn't work out. Mineral spirits and its gone, looks like to me. I'll let you know if I do it, and how it turns out.

And ebb, you comments are very much appreciated. Your rational is sound. I'll give it a go.